PDS Data Product Software Interface Specification (SIS)

For

Mini-RF Advanced Technologies –

Lunar Reconnaissance Orbiter (LRO)

Payload Operations Center

February 25, 2010

Prepared by
Mini-RF Program

Prepared by

Mr. Michael Reid                                                                Date

Mini-RF POC Data Archivist

JHU/APL

Reviewed by                                                              

Mr. David B. LaVallee                                                         Date

Mini-RF Payload Operations Center Manager

JHU/APL

Ms. Helene Winters                                                              Date

Project Manager

JHU/APL

Approved by

Dr. D. Ben Bussey                                                                Date

Mini-RF Principle Investigator

JHU/APL

Ms. Susan Slavney                                                              Date

NASA PDS Representative, Geosciences Node

Washington University, St. Louis

Dr. Charles Acton                                                                Date

NASA PDS Representative, Navigation & Ancillary Information Facility (NAIF) Node

JPL

Table of Contents

1.    Purpose and Scope of Document                                                                                         1

2.    Applicable Documents                                                                                                       1

3.    Relationships with other Interfaces                                                                                     2

4.    Data Product Characteristics and Environment                                                                    2

4.1    Instrument Overview                                                                                                      2

4.1.1    Instrument Description                                                                                             2

4.2    Data Processing                                                                                                            3

4.2.1    Data Processing Levels                                                                                             3

4.2.2    Calibration                                                                                                             5

4.2.3    Science Data Processing Burst Mode                                                                          5

4.2.3.1    Level 0 Burst Mode Processing                                                                           6

4.2.3.2    Level 1 Burst Mode Processing                                                                           6

4.2.3.3    Level 2 Burst Mode Processing                                                                           8

4.2.4    Science Data Products Continuous (Interferometry) Mode                                               8

4.2.4.1    Level 1 Continuous Mode Processing                                                                  8

4.3    Archived Data Products                                                                                                  9

4.3.1    Raw Data                                                                                                             10

    Derived                                                                                                                      12

4.3.2    Burst Mode Products                                                                                             12

4.3.2.1    Level 1                                                                                                         12

4.3.2.2    Level 2                                                                                                         13

4.3.3    Level 3 Polar Mosaics                                                                                            16

4.3.4    Continuous Mode Products                                                                                     17

4.3.4.1    Level 1                                                                                                         17

4.3.5    Calibration Data Products                                                                                       18

4.3.6    Ancillary Data Products                                                                                          19

4.3.6.1    Instrument Housekeeping Data                                                                          19

4.3.6.2    Digital Elevation Model (DEM) Files                                                                 19

4.3.7    SPICE Kernels                                                                                                      19

4.3.8    PDS Archive Files                                                                                                 20

4.4    Data Product Archiving                                                                                                23

4.4.1    Data Flow                                                                                                            23

4.4.2    Labeling and Identification                                                                                      23

4.5    Standards Used in Generating Data Products                                                                   23

4.5.1    PDS Standards                                                                                                      23

4.5.2    Time Standards                                                                                                     24

4.5.3    Coordinate Systems                                                                                               24

4.5.4    Archiving Standard                                                                                                25

4.5.5    Data Storage Conventions                                                                                       25

4.6    Data Validation                                                                                                          25

4.7    Data Product Structure and Organization                                                                        26

4.7.1    File Naming                                                                                                         26

4.7.1.1    File Naming Conventions for the Orbit-Based Science Data Products                       26

4.7.1.2    File Naming Conventions for the Level 3 Polar Mosaics                                        29

4.7.1.3    File Naming Conventions for SPICE Kernels                                                       29

4.7.1.4    File Naming Conventions for the Digital Elevation Model (DEM) File                     30

4.8    Label and Header Descriptions                                                                                      30

4.8.1    PDS Label Parameter Descriptions                                                                            30

4.8.2    Examples of SAR PDS Labels                                                                                 35

4.8.2.1    Example PDS Minimal Label for a LRO Raw PDR Data Product                            35

4.8.2.2    Example PDS label for a LRO Level 1 SAR Data Product                                      36

4.8.2.3    Example PDS label for a LRO Level 2 SAR Data Product                                      38

4.8.2.4    Example PDS Daughter Product Label                                                                41

4.8.2.5    Example PDS label for a LRO Level 3 SAR Data Product                                      43

5.    Applicable Software                                                                                                         45

5.1    Software Distribution And Update Procedures                                                                  45

6.    Appendices                                                                                                                     46

6.1    Level 3+ Derived Data Record (DDR) Products                                                                46

6.1.1.1    SAR Stereo File Naming                                                                                 48

6.2    Glossary                                                                                                                    49

6.3    Acronyms                                                                                                                   49

1.    Purpose and Scope of Document

This Software Interface Specification (SIS) describes the archived Lunar Reconnaissance Orbiter (LRO) Mini-RF instrument science-related data products. Mini-RF is an instrument that flies on the NASA LRO spacecraft. It is a synthetic aperture radar (SAR), which will image and characterize the lunar surface. The Payload Operations Center (POC) is located at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. It hosts processing systems, which will generate levels of science data products from the raw telemetry received from the instrument. The raw SAR data are processed within the POC through Level 2 using Microsoft^®/Vexcel^®’s SAR Processor. This document specifies the format and content of those products and is intended to serve as a guide for producing and using them.

Figure 1: The LRO spacecraft.

This document is intended for scientists and engineers in the planetary science community and others who wish to understand the format and content of the Mini-RF science data products. The SIS applies to the Mini-RF data products produced during the course of LRO Mission operations.

2.    Applicable Documents

The LRO Mini-RF SIS references or is applicable to the following documents:

1        Planetary Data System Standards Reference, NASA/JPL, February 27, 2009, Version 3.8. JPL D-7669, Part-2. Available from http://pds.jpl.nasa.gov/documents/sr/index.html. [Accessed: January 26, 2010].

2        Planetary Data System Archive Preparation Guide, August 29, 2006, Version 1.1, JPL D-31224, NASA/JPL. Available from http://pds.jpl.nasa.gov/documents/apg/index.html. [Accessed: May 8, 2007].

3        Lunar Reconnaissance Orbiter (LRO) Project Instrument Team Data Management and Archive Plan, Mini-RF program.

4        Lunar Reconnaissance Orbiter (LRO) Mini-RF Science Team and PDS Geosciences Node Interface Control Document (ICD), Mini-RF program.

5        Data Interface Control Document for Mini-RF Advanced Technologies – LRO (MRF-2101), Mini-RF program.

6        Archive Volume Software Interface Specification (SIS) for Mini-RF Advanced Technologies (LRO) (MRF-4011), Mini-RF program [DOCUMENT/AV_SIS/MRFLRO_AV_SIS].

7        Lunar Reconnaissance Orbiter Data Management and Archive Plan, 431-PLAN-000182, NASA/GSFC LRO Project.

8        P. L. McKerracher, J. R. Jensen, H. B. Sequeira, R. K. Raney, R. C. Schulze, D. B. J. Bussey, B. J. Butler, C. D. Neish, M. Palsetia, G. W. Patterson, P. D. Spudis, B. J. Thomson, F. S. Turner, Mini-RF calibration, a unique approach to on-orbit synthetic aperture radar system calibration, 2010 [DOCUMENT/MRF_CAL/MRF_CAL_MCKERRACHER_ET_AL2010].

9        J. R. Jensen, LRO Mini-RF S-band transmit polarization ellipse as observed at Green Bank on August 23, 2009 [DOCUMENT/GB_CAL/MRFLRO_CAL_GBT_JENSEN2010].

3.    Relationships with other Interfaces

The LRO data products are produced at the POC and are delivered to the PDS. The products are decompressed radar image files, calibration data, miscellaneous ancillary data, and possibly SPICE kernels. Their formats comply with PDS standards. The image and other files will be archived to the PDS Geosciences node. Any SPICE kernels will be archived at the PDS NAIF node.

4.    Data Product Characteristics and Environment

4.1    Instrument Overview

Mini-RF is an instrument on the LRO spacecraft. It is capable of active burst and continuous mode SAR imaging. The continuous mode images are used to create interferometry (also called “InSAR”) products. High-resolution SAR images of Polar Regions of the lunar surface will be obtained. The search for water ice, particularly in the polar regions of the Moon, is its primary science mission, but it will also characterize the surface roughness and thickness of the regolith.

4.1.1    Instrument Description

The LRO Mini-RF instrument has the following parameters, which describe it. The associated values given here are typical, not absolute, and many of them vary.

Table 1 Description of the LRO Mini-RF instrument.

4.2    Data Processing

There are two modes of data acquisition from the Mini-RF instrument on the LRO spacecraft, burst and continuous mode. Burst mode is referred to in this document as the standard SAR product. Continuous mode (also a type of SAR product) is used to create interferometry products. Processed numeric data products are provided in little-endian format.

4.2.1    Data Processing Levels

There are four levels of SAR data products archived at the PDS: raw, Level 1, Level 2, and Level 3 (mosaics). There is a Level 0 processing performed at the POC; however, these are intermediate products that are not scientifically useful and are not archived at the PDS. Additionally, there are ground calibration and ancillary products. All are generated at the POC. Each product will have a unique file name and follow the file naming convention (see File Naming section 4.7.1). Each product file will be associated with a particular data set (see Table 3). A special product, a refined interferometry product, may also be produced. These are described in Appendix section 6.1. The processing levels given in the DATA_SET_IDs are CODMAC levels. All other references to processing levels in this document are NASA processing levels.

Table 2 The standard NASA and CODMAC processing levels for science data sets. These are used in defining the data set IDs.

Table 3 The archived science data products, their PDS data set IDs and corresponding processing levels. See the description of CODMAC levels in Table 2. ^*SPICE kernels (optional for the Mini-RF instrument) are archived separately at the NAIF PDS node (VOLUME_ID = LROSP_1000).

Table 4 Values of mission and instrument identifying key words.

4.2.2    Calibration

McKerracher et al (2010) [See Sec. 2, Ref. 8] and Jensen (2010) [See Sec. 2, Ref. 9] describe instrument and data calibration that are applied to the CDRs in documents included in the DOCUMENT directory of the PDS archive. The raw calibration data products are available in the CALIB directory in the accompanying archive. See CALIB/CALINFO.TXT for a listing and discussion of these product files.

4.2.3    Science Data Processing Burst Mode

There are three levels of SAR LRO data products produced while the instrument is in burst mode, which are archived at the PDS Level 1, Level 2, and Level 3 (mosaics). The data are created in the cross-product format in either the baseline or zoom resolution modes with the square pixel spacing aspect ratio. Additionally, there are ground calibration and ancillary products. All are generated at the POC. Each product will have a unique file name and follow the file naming convention given in section 4.7.1. The processed science data products are provided in little-endian format (PC_REAL).

The processing of SAR data into imagery involves the following 3 broad processes.

·       Level 0 Processing

·       Level 1 Processing

·       Level 2 Processing

·       Generation of Level 3 mosaics from data from multiple orbits

4.2.3.1    Level 0 Burst Mode Processing

The Level 0 processing is an intermediate step in the production of deliverable SAR products. The resulting Level 0 products are not scientifically useful in themselves, so they are not archived. However, they are mentioned here to aid in the understanding of the deliverable products. The Level 0 Processing steps involve the following:

·       Telemetry Packets Processing (typically CCSDS format)

·       Processing of available on-board calibration and housekeeping data

·       Meta-data Extraction (reading of relevant radar parameters from science data header, reading of ephemeris/attitude/time correlation from relevant files)

·       Parameter Estimation (Doppler centroid and rate estimation for the data strip, geo-location, range and azimuth spectra, raw data histogram)

4.2.3.2    Level 1 Burst Mode Processing

The level 1 Processing can be carried out in Burst Mode or Continuous Mode depending on the whether the instrument acquired the phase history data in the burst or continuous modes. The flow chart for the Burst Mode processor for data acquired in one polarization only is show in Figure 2 below. The processing consists of the following major steps:

• Range Compression
• Range FFT
• Compression Filter
• Range IFFT
• Azimuth Compression
• Azimuth FFT
• Range Migration Curvature Correction
• Slant Range to Ground Range Conversion
• Azimuth IFFT
• Chirp Transform SPECAN
• Radiometric Compensation
• Range radiometric compensation
• Azimuth radiometric compensation
• Multi-look Overlay

Figure 2 The burst mode processor.

4.2.3.3    Level 2 Burst Mode Processing

The level 2 processing steps involve the following:

·       Generation of the corners of the output Level 2 image in the chosen projection. The corners serve to provide processing bounds for the image strip to be ortho-rectified.

·       Image Formation, wherein the L1 image, and optionally an available DEM or GCP file(s) are used to project the image into desired projection.

4.2.4    Science Data Products Continuous (Interferometry) Mode

Continuous mode data acquisition is intended for use in producing interferometric (InSAR) data products. There are two levels of continuous mode products archived at the PDS, Level 1 and possibly derived topographic data (Level 3+). There is a Level 0 processing performed at the POC; however, these are intermediate products that are not scientifically useful and are not archived at the PDS. There are no Level 2 continuous mode products. All are generated at the POC. Each product will have a unique file name and follow the file naming convention (File Naming, section 4.7.1).

4.2.4.1    Level 1 Continuous Mode Processing

The flow chart for data acquired in continuous mode for a single polarization channel is shown in the Figure 3 below. The processing consists of the following major steps:

• Range Compression
• Range FFT
• Compression Filter
• Range IFFT
• Azimuth Compression
• Azimuth FFT
• Range Migration Curvature Correction
• Azimuth IFFT
• Radiometric Compensation
• Range radiometric compensation

Figure 3 The continuous mode processor

4.3    Archived Data Products

The format and organization of the archived science, calibration, and ancillary products are described in this section. Metadata accompanies the Raw PDR and CDR data products in a Vexcel^®-developed human and machine-readable structured text format called “CONI.” These metadata are stored in parameter files of the same name as the data product, except that the file name suffix is .TXT. The associated PDS label contains a reference to the parameter file. The tables in this section contain detailed descriptions of the product files. The Num Files column in the tables indicates the number of files, which make up the specific product.

4.3.1    Raw Data

The Raw Packetized Data Records (PDRs) are in the form of raw binary telemetry in Consultative Committee for Space Data systems (CCSDS) packet format, which have been extracted from frames downlinked from the instrument. PDRs have duplications removed and include any ancillary information needed to understand what is in a given packet. They are retained so that future researchers can reproduce the higher-level products if they so desire. These data will not be reformatted or processed further and are delivered to the PDS with detached minimal PDS labels. Because the higher-level products can be reprocessed as often as desired, there may be a one-to-many relationship a raw data product to a processed data product.

The formats of these packets are identical, but their contents differ. Each of these packets is composed of five segments: the CCSDS Primary Header which contains packet identification information, the CCSDS Secondary Header which contains the packet time stamp, the Science Header which contains associated metadata, the Science Data which contains the data samples, and a trailer (“Other Data”) which contains transmission information. Byte values are 8-bits long, Integer values are 32-bits long, short (integers) are 16-bits long, and floating point values are 32-bit IEEE numbers. These data only are provided in big-endian format.

The science data are time-ordered and consist of Vertical (V) or Horizontal (H) polarization channel samples contained within a pulse. The packets will contain either H or V channel data, never both in the same packet. The “V/H Channel Indicator” flag in the Science Header indicates if the data are H or V channel. Data gaps in the derived products or breaks in the sequence count field in the primary CCSDS packet header would indicate missing packets.

Table 5 Layouts of the Raw Data PDRs. Unlike the other data products, the Raw PDR files are delivered in big-endian format.

Table 6 Files containing the Raw Data PDRs (DATASET_ID: LRO-L-MRFLRO-1-PDR-Vn.n).

4.3.2    Derived Burst Mode Products

Each pixel in the cross product burst contains like power intensities (HH*, VV*) and the cross power intensity (HV*). The “H” and “V” notation as used here is not to be confused with broadcast and receive polarization.

4.3.2.1    Level 1

The Level 1 data products are Level 1 Calibrated Data Records (CDRs). The POC produces Level 1 SAR CDRs by ingesting the Level 0 EDRs and associated Level 0 ancillary files into the SAR processor (Level 0 data are intermediate products generated from raw (PDR) products. Level 0 data are not archived in PDS.). The Level 1 CDRs are SAR images in range and azimuth orientation with pixel values in beta naught, which have been radiometrically and polarmetrically calibrated. Each cross-product image file contains simple lines of pixels. Each pixel consists of four 4-byte floating-point numbers for a total of 16 bytes. The first two floating-point numbers are the image intensity values for the horizontal (H) and vertical (V) channel receive. The second two numbers are the real and imaginary parts of the single complex number, which gives the cross power intensity image between the H & V receive. H & V represent the complex amplitudes of the horizontal and vertically polarized backscatter respectively. An ‘*’ represents a complex conjugate of H or V. The Level 1 products are the lowest level usable science data products.

Table 7 Level 1 files. IMG DAT files are binary instrument data and TIF are TIFF images (DATASET_ID: LRO-L-MRFLRO-3-CDR-Vn.n).

4.3.2.2    Level 2

The Level 2 burst mode data products are CDRs that the POC produces by ingesting the Level 1 CDRs into the Level 2 SAR processor. The Level 2 CDRs differ from the Level 1 products in that they are orthorectified and are re-sampled into map projections. Typically, images of regions between ±79° of the lunar equator will be rendered into equirectangular projections. Images of regions closer to the lunar poles will be rendered into oblique cylindrical projections. The “equator” of the map projection will correspond to the line of longitude that the subspacecraft point crossed at the equator before the data collection. These will be archived both at the POC and at the PDS. Each pixel is of the same data type as that of the Level 1 image. Seven derived products, sometimes referred to as “daughter products” are included along with each Level 2 CDR. These daughter products include four stokes parameter files, a circular polarization ratio file, a same sense polarization ratio products, and an opposite sense polarization ratio product.

4.3.2.2.1    Stokes Parameters

All Level 2 CDR image products are each accompanied by four Stokes parameters files. Mini-RF transmits a right circular polarized signal, and receives Horizontal and vertical polarized signals, and the phase between the polarizations. The Level 2 file consists of four pieces of information per pixel. The received power on the horizontal polarization (E_RH), the received power in the vertical polarization (E_RV) and the real and imaginary portions of the cross product between the two polarization signals (Re E_RH E_RV^* & Im E_RH E_RV^* ).

The first Stokes parameter, defined as S₁ = <|E_LH|² + |E_LV|²>, represents the total power or total intensity of the received field.

The second Stokes parameter, defined as S₂ = <|E_LH|² - |E_LV|²>, represents the difference between the horizontally and vertical components of the polarized portion of the received em field.

The third and fourth Stokes parameters are defined as S₃ = 2 Re< E_LH E_LV^*> and S₄ = -2 Im < E_LH E_LV^*>, respectively. They represent respectively the cosine and the sine of the average phase between the horizontally and vertically polarized components of the received field.

4.3.2.2.2    Polarization Products

4.3.2.2.2.1    Same sense circular polarization (SC)

Mini-RF transmits two orthogonal, linearly polarized waves with a phase shift of (nominally)one quarter of the wavelength, and the resulting superposition of these two forms a (nominally) circularly polarized beam. The same sense circular polarization product describes the polarization state of the received field that has an identical polarization to the transmitted beam. This product is calculated as one half of the difference between the Stokes S₁ and S₄ parameters (SC = 0.5*S₁ – 0.5*S₄).

4.3.2.2.2.2    Opposite sense circular polarization (OC)

The opposite sense circular polarization product describes the polarization state of the received field that has the opposite circular polarization to the transmitted beam. This product is calculated as one half of the sum of the Stokes S1 and S4 parameters (OC = 0.5*S₁ + 0.5*S₄).

4.3.2.2.2.3    Circular polarization ratio (CPR)

This dimensionless parameter is the ratio of the same sense circular polarization to the opposite sense circular polarization (CPR = SC / OC). The average CPR value of the entire lunar surface is on the order of 0.3. CPR values for certain types of surface deposits may be either anomalously low (near zero for very smooth terrain) or anomalously high (>1.0 for blocky large-scale rough features). High CPR also is due to volumetric backscattering from thick deposits of frozen volatiles, such as water-ice.

Degree of polarization (m): The fraction of radar backscatter that is polarized is given by the ratio m = (S₂² + S₃² + S₄²)^1/2/S₁. The average value of m at the moon is about 0.6.

Table 8 Level 2 data products (DATASET_ID: LRO-L-MRFLRO-3-CDR-MAP-Vn.n).

4.3.3    Level 3 Polar Mosaics

The Level 3 Burst mode data products are Derived Data Records (DDRs) generated from multiple Level 2 CDRs. They are mosaics that the POC produces by ingesting the Level 2 Stokes parameter files into the ISIS software. Four Level 3 mosaics will be produced of each lunar pole (i.e., regions above 80° latitude) per imaging opportunity. Unlike the lower-level products, these are composed of data sets collected during multiple acquisitions and are produced manually using the ISIS software provided by the Astrogeology branch of the USGS. The final ISIS products are archived at the PDS. Level 3 is the final stage of data processing performed at the POC. These will be archived both at the POC and at the PDS.

Table 9 Level 3 Burst Mode SAR Mosaic data products produced using the USGS ISIS software (DATASET_ID: LRO-L-MRFLRO-3-CDR-MOSAIC-Vn.n).

See Appendix sec. 6.1 for a description of additional derived Level 3+ data products.

4.3.4    Continuous Mode Products

4.3.4.1    Level 1

The continuous mode Level 1 data products are Level 1 Calibrated Data Records (CDRs). These may be used to create refined interferometric products. The POC produces Level 1 SAR CDRs by ingesting the Level 0 EDRs and associated Level 0 ancillary files into the Vexcel^® SWATH processor. The Level 1 CDRs are SAR images and interferometry in range and azimuth orientation with pixel values in beta naught. The data are created in single-look complex format with pixel spacing in the native sampling aspect ratios. They are the lowest level usable science data products. There are no additional products produced from interferometry data.

Table 10 Level 1 files (DATASET_ID: LRO-L-MRFLRO-3-CDR-INSAR-Vn.n).

4.3.5    Calibration Data Products

Calibration data products used in processing consist of raw, packetized data records received from the Mini-RF instrument on-board the spacecraft and produced by calibration activities using the Arecibo Radio Telescope in Puerto Rico and the Greenbank Radio Telescope in West Virginia. These are described in papers referenced in sec. 4.2.2.

Table 11 Calibration products. These products are found in the CALIB directory in the archive volume.

4.3.6    Ancillary Data Products

Ancillary data accompanies the science data and are also archived at the POC and the PDS. They too will have detached PDS standard labels.

4.3.6.1    Instrument Housekeeping Data

The Instrument Housekeeping Data contain information about the state of the instrument. The data are provided in comma separated variable (CSV) text files. The exact contents of this may vary depending on data rate and other factors. See Table 12 for a description of the ancillary data product that contains these data.

4.3.6.2    Digital Elevation Model (DEM) Files

The DEM files are produced using both interferometric and SAR stereo techniques. They consist of cartographically projected maps of topography. They will be used by scientists to study the topography of the polar regions.

Table 12 List of ancillary data files.

4.3.7    SPICE Kernels

The SPICE Kernels are structured parameter files that describe, among other things, the ephemeris and attitude of the spacecraft, the spatial orientation of the instrument, the ephemeris and physical parameters of the Earth, Moon and other natural bodies in the Solar System, the relationship between spacecraft time and time as measured on Earth, and the locations and orientations of ground stations. Some of these files are standard products generated by the NAIF team at JPL and are not mission specific. Others are produced specifically for a particular mission or instrument. Some of these files are binary and others are text. The SPICE kernels generated for the overall LRO mission will not be part of the data archive generated by the POC and delivered to the PDS. The LRO project will manage these and provide for their archiving. If SPICE kernels are generated specifically for the Mini-RF instrument, they will be archived separately at the NAIF node of the PDS. These are optional products. The Mini-RF project will determine during the course of the mission if any instrument-specific SPICE kernels are to be created. There existence and archival at the NAIF node will be noted in the AAREADME.TXT file that accompanies the archive volume.

SPICE Kernel files are intended for use with the SPICE software library. This is a software product from the Navigation and Ancillary Information Facility (NAIF) at the NASA Jet Propulsion Laboratory (JPL), which contains functions that perform computations for space mission-related and astronomical applications. Any SPICE kernels used in product generation will be listed in the SOURCE_PRODUCT_ID field of the accompanying PDS labels.

Table 13 SPICE kernels optionally delivered with the product sets.

4.3.8    PDS Archive Files

There is a set of standard files that accompany a data product to be archived at the PDS. These files and some supporting documents are described here. See the Mini-RF LRO Data Archive Volume SIS [sec. 6] document for more information about these files and their locations in the archive.

Table 14 PDS standard files that contain descriptive and indexing information about the archive.

4.4    Data Product Archiving

The LRO Mini-RF POC is responsible for science data product generation, validation, and archiving. The POC supports and works with the LRO mission operations, the LRO Mini-RF science team, and the PDS.

4.4.1    Data Flow

Prior to science phase of the LRO mission, the POC produces sample data products from raw telemetry generated by spacecraft and instrument simulators located at GSFC. During the mission, the spacecraft control center receives the science data downlink from the spacecraft on one channel and the housekeeping data on a second channel. The MOC sends the raw data from the Mini-RF instrument to the POC through a data link. At the POC, the Vexcel^® SAR and Calibration processors process the raw SAR data through levels 0, 1, and 2. Level 3 mosaics are produced using the ISIS software from the USGS. Interferometry data are processed through a separate processor. Software applications developed specifically for and running only at the POC facilitate this processing and package the data for later archiving at the PDS.

The Vexcel^® SAR processors consist of the SKY Level 0 processor (products not archived), the SWATH Level 1 processor, and the ORTHO Level 2 processor. Each processor’s output products are the input to the next level’s processor. Calibration is performed by the Vexcel^® CALPRO processor.

4.4.2    Labeling and Identification

With the exception of the Raw data, all data products described in this document which are to be delivered to the PDS are accompanied by full PDS standard labels. Detached minimal labels accompany the Raw data. The PDS labels are detached text files, which describe the associated product file. There will be one label file for each product file. These labels conform to the PDS version 3 standards. A product ID in its PDS label will uniquely identify each product. The file name may be used for the product ID as long as it is unique.

The PDS label describes and provides ancillary information about the data product. They are written in a structured text language called “Object Description Language (ODL).” Examples of a LRO Mini-RF PDS labels are given in section 4.8.2. Note that not all of the keywords are necessarily present in a given PDS label.

4.5    Standards Used in Generating Data Products

4.5.1    PDS Standards

The LRO Mini-RF science and calibration data products are constructed according to the data object concepts developed by the PDS. By adopting the PDS format, the data products are consistent in content and organization with other planetary image collections. In the PDS standard, the data product file is grouped into objects with PDS labels describing the objects. All PDS labels are written in ODL, a subset of the Parameter Value Language (PVL), which is a structured text format (Applicable Document 1). The LRO Mini-RF data products contain:

1. PDS Label Files describing the specific product (including external data files)
2. SAR or Interferometry image data files.
3. Stokes parameter files.
4. Calibration data files.
5. Ancillary files containing housekeeping data, lunar geometric data, and metadata in an ASCII table format.
6. Documentation.

The image data will be delivered in an uncompressed form.

4.5.2    Time Standards

All time values in the PDS labels shall be given in Coordinated Universal Time (UTC). The time in UTC shall be represented in ISO calendar format standard: yyyy-mm-ddThh:mm:ss.ss eg 2006-08-14T15:02:10.12.

The spacecraft time in Mission Elapsed Time (MET) shall also be given in the science product labels in the form of SPICE spacecraft clock (SCLK) strings. An SCLK string has the form “<partition>/<MET seconds>:<MET subseconds>”, where partition is the current spacecraft clock partition, MET seconds is the mission elapsed time in seconds, and MET subseconds is the vernier counter representing a fraction of a second. An example of an SCLK string is “1/123456789:123456”.

4.5.3    Coordinate Systems

Table 11 lists the computational assumptions for the geometric and viewing data provided in the PDS label. There are two reference frames (coordinate systems) in use: 1) the International Celestial Reference Frame (ICRF), also frequently called the J2000 or the E.M.E. 2000 frame, used for target and spacecraft position and velocity vectors, and instrument pointing and 2) a lunar body-fixed reference frame, used for specifying certain viewing geometry vectors and target location. The lunar body-fixed frame used by the Mini-RF investigation is the Mean Earth/Polar Axis frame (commonly abbreviated as ME), as realized using NASA’s SPICE products (Frames Kernel).

Table 15 Computational assumptions.

4.5.4    Archiving Standard

The science data products will be archived by orbit number and the complete archive will consist of approximately 720 orbits.

4.5.5    Data Storage Conventions

All text files are of standard ASCII format and in accordance with PDS standards, each line in a text file terminates with a carriage return (ASCII 13) and line feed (ASCII 10) end of line (EOL) marker (i.e., <CR><LF>).

4.6    Data Validation

Basic data validation is performed at the POC and consists of the following:

• POC staff check the data products for conformance to this document and the Archive Volume SIS, and for valid science content.
• Generation of data products and volumes, together with validation are completed within the required validation period of six months from the availability of processing input data.
• Prior to the first delivery of the products to the PDS, PDS representatives and other interested parties review a sample product set generated by the POC and may request changes to the product set as necessary to conform to the SIS.
• The data pipeline is also reviewed as part of the validation process.
• In accordance with PDS requirements, the design of the data products as described by this Data Product SIS, and as shown by a set of sample products, undergoes a peer review prior to the beginning of processing. A review committee made up of a few scientists who are knowledgeable in the area along with representatives from the POC and the PDS evaluate the products. They may produce a list of liens against the product set that will be resolved prior to PDS archiving.

4.7    Data Product Structure and Organization

4.7.1    File Naming

The file names developed for any PDS archive are restricted to a maximum 27-character base name and 2 or 3 character extension name with a period separating the file and extension names. Also known as the “27.3” format, this is compliant with the ISO 9660 Level 2 specification, which is required by PDS. All file names for products archived at the PDS contain only capital letters, numerals, and underscores (except for the one period ‘.’ which separates the file basename from the file extension). All files begin with the one character instrument identifier L (LRO) which is the file designation for all LRO Mini-RF files. In accordance with PDS standards, all file names are in capital letters. The three-character file extension for each type of product file is given in the File Extension column of each product description table in section 4.2.1.

4.7.1.1    File Naming Conventions for the Orbit-Based Science Data Products

The following table describes the detailed naming convention used for the Raw, Level 1, Level 2, and Level 3 data products. The Vexcel^® processors produce the Level 1 and Level 2 products.

Format: Mfm_ooooo_ltt_abu_ccdeee _Vv.ext

M = Indicates the instrument.

L = LRO

F = Forerunner

B = Both

f = Frequency band

       S = S-band

       X = X-band

       B = Both

       N = N/A

m = Radar mode

       B = Baseline SAR

       I = Interferometry

       S = Scatterometry

       Z = Zoom

       A = Arecibo Radio Telescope Calibration

       G = Greenbank Radio Telescope Calibration

       C = Other Calibration

       O = Other (housekeeping, etc.)

ooooo = The orbit number in which the data acquisition began. Numeric, range 00001…99999.

l = Processing level

       R = Raw PDR

       1 = Level 1

       2 = Level 2

       3 = Level 3

tt = File type

       PD = Packetized Data Records

       CD = Calibrated Data Records

       S1 = Stokes Parameter 1 File

       S2 = Stokes Parameter 2 File

       S3 = Stokes Parameter 3 File

       S4 = Stokes Parameter 4 File

       SC = Same-Sense Polarization Image File

       OC = Opposite-Sense Polarization Image File

       CP = Circular Polarization Ratio image File

HK = Instrument Housekeeping data (Associated with

     RAW data only)  

a = projection

       O = Oblique cylindrical

       E = Equirectangular

       P = Polar stereographic

       X = N/A (for Raw, Level 1, Housekeeping, cal, etc.)

b = pixel resolution bin scale in pixels per degree (ppd)

       A = 1 ppd

       B = 2 ppd

       C = 4 ppd

       See Table 16.

       X = N/A (calibration or housekeeping data)

Table 16 Association of letter-designated bins for pixel resolutions.

u = bit type and scaling

       U = Unnormalized floating point

       F = Normalized floating point

       B = Byte

cc = Lunar center latitude to nearest whole degree

       Numeric value range 00…90.

       XX = N/A or Unknown

d = hemisphere of latitude

       N = North latitude

       S = South latitude

       X = N/A

eee = Lunar center longitude to nearest whole degree

       Numeric value range 000…359.

       XXX = N/A or Unkown

v = Product version number. Numeric range 1…9.

ext = Product type (complies with PDS conventions)

       IMG = Processed image file

       DAT = Unformatted binary data (e.g., raw files)

       JPG = JPEG formatted browse images

       TXT = Unstructured text data (e.g., parameter

              files)

       CSV = Comma Separated Value text files

              (housekeeping)

       LBL = PDS label file

The following is an example file name of a Mini-RF SAR mode raw data product. It is baseline SAR, S-band, raw data, packetized data record, byte format, no projection, 75 m/pixel resolution, center coordinates 82ºN, 231º, orbit 512, version 1.

LSB_00512_RPD_XJB_82N231_V1.DAT

The following is an example file name of a Mini-RF LRO SAR mode level 2 CDR data product. It is zoom mode, X-band, level 2 processed, calibrated data record, oblique cylindrical projection, 512 pixels/degree resolution, unnormalized floating point format, center coordinates 82ºN, 231º, orbit 617, version 3.

LXZ_00617_2CD_OJU_82N231_V3.IMG

The following is an example file name of a Mini-RF LRO SAR mode level 2 stokes 3 data product. It is baseline SAR mode, S-band, level 2 processed, stokes parameter, simple cylindrical projection, unnormalized floating point format, 512 pixels/degree resolution, center coordinates 82ºN, 231º, orbit 512, version 2.

LSB_00512_2S3_EJU_82N231_V2.IMG

The following is an example file name of a Mini-RF LRO calibration data product. It is a raw product collected using the Arecibo Radio Telescope. The spacecraft orbit number is 975, it is a raw packetized data record product, bit type is binary, the location on the Moon is not specified, and it is version 1.

LSA_00975_RPD_XXB_XXXXXX_V1.DAT

4.7.1.2    File Naming Conventions for the Level 3 Polar Mosaics

The following table describes the detailed naming convention for this dataset. These products are mosaics. They contain data from multiple orbits. The file names of the polar mosaics follow the same naming convention as the other science products, except that the center latitude and longitude given in their file names are that of the center of the mosaic and the orbit number is that of the highest orbit number product among the lower-level products used in the mosaic.

The following is an example file name of a Mini-RF LRO polar mosaic, zoom, SAR, S-band, level 3, same-sense polarization, unnormalized floating point, north pole mosaic product, 2048 ppd, version 01. The highest orbit number data that was used was orbit 752.

LSZ_00752_3SC_PLU_90N000_V1.IMG

All files have a corresponding PDS label of the same name except for a suffix ending .LBL.

4.7.1.3    File Naming Conventions for SPICE Kernels

The Mini-RF instrument kernel is the only LRO kernel, which might be created, by the POC and therefore, the only one discussed here. The creation of this product is optional. The LRO project creates other SPICE kernels for the mission, but they are created and archived separately and not discussed here. The file naming convention for the sole Mini-RF SPICE kernels is lro_mrf_vv.ti where nn is the version number and the “.ti” suffix indicates that it is an instrument kernel. The kernel filename is in all lower-case per PDS NAIF node standards.

Instrument kernel (IK):

Format: lro_mrf_vnn.ti

Label: lro_mrf_vnn.lbl

4.7.1.4    File Naming Conventions for the Digital Elevation Model (DEM) File

The DEM naming convention and that of its associated parameter file are given below. yyyymmdd is the date that they were released. If provided, the DEM files will be included in the EXTRAS directory within the archive volume and will not have associated PDS labels.

Format: LUNAR_DEM_yyyymmdd_vv.DAT

Format : LUNAR_DEM_yyyymmdd_vv.TXT

4.8    Label and Header Descriptions

4.8.1    PDS Label Parameter Descriptions

The key words used in LRO Mini-RF data product PDS labels are described in Table 17 below.

The a_axis_radius element provides the value of the semimajor axis of        

the ellipsoid that defines the approximate shape of a target body.  'A' is usually in the equatorial plane.

The b_axis_radius element provides the value of the intermediate axis        

of the ellipsoid that defines the approximate shape of a target body.        

'B' is usually in the equatorial plane.

The c_axis_radius element provides the value of the semiminor axis of        

the ellipsoid that defines the approximate shape of a target body.  'C' is normal to the plane defined by 'A' and 'B'.

The BANDS element indicates the number of bands in the image.

BAND_NAME is the name given to a single band in a multi-band image           

or image qube.  These identify the components of the radar image pixel.

The band_storage_type element indicates the storage                          

sequence of lines, samples and bands in an image.  The                       

values describe, for example, how different samples are                      

interleaved in image lines, or how samples from different                    

bands are arranged sequentially.

The carrier frequency of the SAR in Hertz.

The center_latitude element provides a reference latitude for the map projections (always 0 for oblique cylindrical) and a center point for Level 1 images.

The coordinate_system_name element provides the full name of the coordinate system to which the state vectors are referenced.

There are three basic types of coordinate systems: body-fixed rotating, body-fixed non-rotating and inertial. A body-fixed coordinate system is one associated with a body (e.g., the Moon).

The full name given to the data set.

The maximum numerical value of longitude unless it crosses the            

Prime Meridian.

The sensor beam incidence angle. The angle between the local vertical and the spacecraft direction.

The unique identifier for the spacecraft which carries the instrument.

Describes the instrument mode which is identified by the instrument_mode_id element.

The instrument-dependent designation of operating mode.

Identifies the type of latitude (planetocentric) used in the labels, e.g., for the maximum, minimum, center, reference, and standard-parallel latitudes.

The line index of the first pixel that was physically recorded at the beginning of the image array.

The line offset value of the map projection origin position from the line and sample 1,1 (line and sample 1,1 is considered the upper left corner of the digital array).

The total number of data instances along the vertical axis of an image.

Identifies the type of projection characteristic of a given map, always oblique cylindrical in this case.

The scale of the map in pixels/degree. The scale is defined as the ratio of the actual distance between two points on the surface of the target body to the distance between the corresponding points on the map.

One of the three angles defining the oblique coordinate system used in the   

OBLIQUE CYLINDRICAL projection.  This is the ordinary latitude in degrees 

of the pole (Z axis) of the oblique system.

One of the three angles defining the oblique coordinate system used in the   

OBLIQUE CYLINDRICAL projection.  This is the ordinary longitude in degrees   

of the pole (Z axis) of the oblique system.

One of the three angles defining the oblique coordinate system used in the OBLIQUE CYLINDRICAL projection.  This is a rotation in degrees around the polar (Z) axis of the oblique system that completes the transformation from  

standard to oblique coordinates.

Identifies the direction of longitude (e.g. EAST, WEST) for a planet.  This is EAST for the Moon.

The full_name of the individual mainly responsible for the production of a data set.

The date when a published document was issued.

The zero latitude in a rotated spherical coordinate system that was used in a given map_projection_type.

The zero longitude in a rotated spherical coordinate system that was used in a given map_projection_type.

Identifies the unique identifier associated with a specific release of a data set. All initial releases should use a RELEASE_ID value of '0001'.

The stored number of bits, or units of binary information, contained in a 

line_sample value.

The sample index for the first pixel that was physically recorded at the beginning of the image array.  Always 1 for Mini-RF images.

The sample index for the last pixel that was physically recorded at the end of the image array.

The data storage representation of sample value.  PC_REAL for Mini-RF images.

The height on the surface of the target of the projection of a pixel onto the surface.  This is the line spacing in Mini-RF images.

The width on the surface of the target of the projection of a pixel onto the surface.  This is the pixel spacing in Mini-RF images. 

The standard deviation (sigma value) of the pixel values in the image array.

The minimum numerical value of longitude unless it crosses the Prime Meridian.

Table 17 The PDS label keywords used in the Mini-RF labels.

4.8.2    Examples of SAR PDS Labels

4.8.2.1    Example PDS Minimal Label for a LRO Raw PDR Data Product

PDS_VERSION_ID = PDS3

LABEL_REVISION_NOTE = "2010-JHU/APL Mini-RF LRO Ver. 1"

RECORD_TYPE = UNDEFINED

FILE_NAME = "LSZ_01408_RPD_XKB_32N355_V1.DAT"

DATA_SET_ID = "LRO-L-MRFLRO-1-PDR-V1.0"

DATA_SET_NAME = "LRO MOON MINI-RF 1 PACKETIZED DATA RECORD

V1.0"

PRODUCER_ID = "JHUAPL"

PRODUCER_FULL_NAME = "MINI-RF POC TEAM"

PRODUCER_INSTITUTION_NAME = "JOHNS HOPKINS UNIVERSITY APPLIED PHYSICS

LABORATORY"

PRODUCT_ID = "LSZ_01408_RPD_XKB_32N355_V1"

PRODUCT_VERSION_ID = "1.0"

ORIGINAL_PRODUCT_ID = "

PacketsFrom2009290_20091017_142550_20100115_214904.down"

SOFTWARE_VERSION_ID = "1.0"

PRODUCT_CREATION_TIME = 2010-02-05T04:39:01

RELEASE_ID = "0001"

MISSION_NAME = "LUNAR RECONNAISSANCE ORBITER"

INSTRUMENT_HOST_NAME = "LUNAR RECONNAISSANCE ORBITER"

INSTRUMENT_HOST_ID = LRO

INSTRUMENT_NAME = "MINI-RF LRO"

INSTRUMENT_ID = MRFLRO

TARGET_NAME = MOON

MISSION_PHASE_NAME = "NOMINAL MISSION"

START_TIME = 2009-10-17T14:25:50.922

STOP_TIME = 2009-10-17T14:32:57.921

ORBIT_NUMBER = 0

DESCRIPTION = "LRO SAR Packetized Data Record (PDR) file.

The Raw Packetized Data Records (PDRs) are in the form of raw binary

telemetry received in CCSDS packet format, which have been extracted from

frames downlinked from the instrument. PDRs have duplicates removed and

include any ancillary information needed to understand what is in a given

packet. They are retained so that future researchers can reproduce the

higher-level products if they so desire."

/* Metadata Associated with the Image. */

OBJECT = PARAMETER_FILE

^TEXT = "LSZ_01408_RPD_XKB_32N355_V1.TXT"

RECORD_TYPE = STREAM

FILE_RECORDS = 16

OBJECT = TEXT

PUBLICATION_DATE = 2010-02-05

NOTE = "A parameter file generated by the raw data

processor."

END_OBJECT = TEXT

END_OBJECT = PARAMETER_FILE

END

4.8.2.2    Example PDS label for a LRO Level 1 SAR Data Product

PDS_VERSION_ID = PDS3

LABEL_REVISION_NOTE = "2010-JHU/APL Mini-RF LRO Ver. 1"

/* File Identification and Structures. */

RECORD_TYPE = FIXED_LENGTH

RECORD_BYTES = 26032

FILE_RECORDS = 23308

/* Pointer to data object. */

^IMAGE = "LSZ_01408_1CD_XKU_32N355_V1.IMG"

/* Identification Data Elements. */

DATA_SET_ID = "LRO-L-MRFLRO-4-CDR-V1.0"

DATA_SET_NAME = "LRO MOON MINI-RF 4 CALIBRATED DATA RECORD

V1.0"

PRODUCER_ID = "JHUAPL"

PRODUCER_FULL_NAME = "MINI-RF POC TEAM"

PRODUCER_INSTITUTION_NAME = "JOHNS HOPKINS UNIVERSITY APPLIED PHYSICS

LABORATORY"

PRODUCT_ID = "LSZ_01408_1CD_XKU_32N355_V1"

PRODUCT_VERSION_ID = "1.0"

ORIGINAL_PRODUCT_ID = "

PacketsFrom2009290_20091017_142550_20100115_214904.000.cp"

MISSION_PHASE_NAME = "NOMINAL MISSION"

PRODUCT_CREATION_TIME = 2010-02-05T22:05:17

RELEASE_ID = "0001"

MISSION_NAME = "LUNAR RECONNAISSANCE ORBITER"

INSTRUMENT_HOST_NAME = "LUNAR RECONNAISSANCE ORBITER"

INSTRUMENT_HOST_ID = "LRO"

INSTRUMENT_NAME = "MINI-RF LRO"

INSTRUMENT_ID = MRFLRO

TARGET_NAME = MOON

SOURCE_PRODUCT_ID = {"LRO_SCLK_20100202_00.TSC","naif0009.tls"}

START_TIME = 2009-10-17T14:25:53.362224

STOP_TIME = 2009-10-17T14:27:40.799

SPACECRAFT_CLOCK_START_COUNT = "UNK"

SPACECRAFT_CLOCK_STOP_COUNT = "UNK"

ORBIT_NUMBER = 1408

INCIDENCE_ANGLE = 53.61261526<deg>

CENTER_FREQUENCY = 2380.00008611<GHz>

INSTRUMENT_MODE_ID = "ZOOM_S"

INSTRUMENT_MODE_DESC = "SAR"

SOFTWARE_NAME = "FOCUS"

SOFTWARE_VERSION_ID = "9.0.320"

LOOK_DIRECTION = LEFT

DESCRIPTION = "Mini-RF Level 1 SAR Calibrated Data Record

(CDR) file. The Level 1 data product is the lowest level of processed data

product that is scientifically useable. It consists of a calibrated, but not

georectified SAR image."

/* The ground range/slant range coefficients. */

LRO:RANGE_COEFFICIENT_SET = ( ("2009-10-17T14:25:53.386",

62716.470892, 7.696415E-01, 3.368160E-06, -3.310459E-11),

("2009-10-17T14:26:01.206", 62716.471172, 7.692234E-01, 3.373354E-06,

-3.313990E-11), ("2009-10-17T14:26:06.319", 62716.471997, 7.689241E-01,

3.377114E-06, -3.316900E-11), ("2009-10-17T14:26:11.733", 62716.470219,

7.685646E-01, 3.381498E-06, -3.319549E-11), ("2009-10-17T14:26:16.846",

62716.469516, 7.682650E-01, 3.385265E-06, -3.322443E-11),

("2009-10-17T14:26:22.259", 62716.471800, 7.679047E-01, 3.389759E-06,

-3.325698E-11), ("2009-10-17T14:26:27.372", 62716.470879, 7.676055E-01,

3.393422E-06, -3.327958E-11), ("2009-10-17T14:26:32.786", 62716.470899,

7.672450E-01, 3.397908E-06, -3.331208E-11), ("2009-10-17T14:26:37.899",

62716.468868, 7.669451E-01, 3.401656E-06, -3.333879E-11),

("2009-10-17T14:26:43.312", 62716.471006, 7.665846E-01, 3.406134E-06,

-3.337045E-11), ("2009-10-17T14:26:48.425", 62716.469268, 7.662236E-01,

3.410591E-06, -3.340105E-11), ("2009-10-17T14:26:53.839", 62716.470149,

7.658628E-01, 3.415113E-06, -3.343629E-11), ("2009-10-17T14:26:58.952",

62716.467871, 7.655629E-01, 3.418765E-06, -3.345736E-11),

("2009-10-17T14:27:04.366", 62716.469982, 7.651406E-01, 3.424016E-06,

-3.349598E-11), ("2009-10-17T14:27:09.479", 62716.469638, 7.648401E-01,

3.427802E-06, -3.352542E-11), ("2009-10-17T14:27:14.892", 62716.467454,

7.644179E-01, 3.432936E-06, -3.355662E-11), ("2009-10-17T14:27:20.005",

62716.467937, 7.640558E-01, 3.437508E-06, -3.359395E-11),

("2009-10-17T14:27:25.419", 62716.468774, 7.636945E-01, 3.441921E-06,

-3.362111E-11), ("2009-10-17T14:27:30.532", 62716.468191, 7.633325E-01,

3.446382E-06, -3.365133E-11), ("2009-10-17T14:27:38.341", 62716.468455,

7.627890E-01, 3.453189E-06, -3.370367E-11) )

/* Data Object Description. */

OBJECT = IMAGE

NAME = "MINI-RF SAR DATA"

CENTER_LONGITUDE = -4.716889<deg>

CENTER_LATITUDE = 32.260219<deg>

MAXIMUM_LATITUDE = 35.146284<deg>

MINIMUM_LATITUDE = 29.373404<deg>

WESTERNMOST_LONGITUDE = 354.934983<deg>

EASTERNMOST_LONGITUDE = 355.606469<deg>

LINES = 23308

LINE_SAMPLES = 1627

SAMPLE_TYPE = PC_REAL

SAMPLE_BITS = 32

MINIMUM = 0.000000000

MAXIMUM = 7.224467278

MEAN = 0.294750041

STANDARD_DEVIATION = 0.011127740

SCALED_PIXEL_HEIGHT = 7.500000000000

SCALED_PIXEL_WIDTH = 7.500000000000

LRO:AZIMUTH_RESOLUTION = 15.674092

LRO:RANGE_RESOLUTION = 30.486847

LINE_EXPOSURE_DURATION = 0.004609439305

BANDS = 4

BAND_STORAGE_TYPE = SAMPLE_INTERLEAVED

BAND_NAME = ("H RECEIVE INTENSITY", "V RECEIVE

INTENSITY", "CROSS POWER INTENSITY (REAL)", "CROSS POWER INTENSITY

(IMAGINARY)")

DESCRIPTION = "The ground range detected cross-product

polarimetric image file. Each pixel is represented by two 4-byte floating

point values and an 8-byte complex value (one 4-byte floating point real

and one 4-byte floating point imaginary component) for a total of 16 bytes

per pixel. The first two numbers are the intensity images for H and V

receive, respectively. The complex value is the cross power intensity

image between the H and V receive."

END_OBJECT = IMAGE

/* Metadata Associated with the Image. */

OBJECT = PARAMETER_FILE

^TEXT = "LSZ_01408_1CD_XKU_32N355_V1.TXT"

RECORD_TYPE = STREAM

FILE_RECORDS = 1815

OBJECT = TEXT

PUBLICATION_DATE = 2010-02-05

NOTE = "A parameter file generated by the SAR

data processor."

END_OBJECT = TEXT

END_OBJECT = PARAMETER_FILE

END

4.8.2.3    Example PDS label for a LRO Level 2 SAR Data Product

PDS_VERSION_ID = PDS3

LABEL_REVISION_NOTE = "2010-JHU/APL Mini-RF LRO Ver. 1"

^IMAGE = "LSZ_01408_2CD_OKU_32N355_V1.IMG"

RECORD_TYPE = FIXED_LENGTH

RECORD_BYTES = 27312

FILE_RECORDS = 23616

DATA_SET_ID = "LRO-L-MRFLRO-5-CDR-MAP-V1.0"

DATA_SET_NAME = "LRO MOON MINI-RF 5 MAP-PROJECTED CALIBRATED

DATA REC V1.0"

PRODUCER_ID = "JHUAPL"

PRODUCER_FULL_NAME = "MINI-RF POC TEAM"

PRODUCER_INSTITUTION_NAME = "JOHNS HOPKINS UNIVERSITY APPLIED PHYSICS

LABORATORY"

PRODUCT_ID = "LSZ_01408_2CD_OKU_32N355_V1"

PRODUCT_VERSION_ID = "1.0"

ORIGINAL_PRODUCT_ID = "

PacketsFrom2009290_20091017_142550_20100115_214904.000.ortho_OC"

MISSION_PHASE_NAME = "NOMINAL MISSION"

PRODUCT_CREATION_TIME = 2010-02-05T14:19:17

RELEASE_ID = "0001"

MISSION_NAME = "LUNAR RECONNAISSANCE ORBITER"

INSTRUMENT_HOST_NAME = "LUNAR RECONNAISSANCE ORBITER"

INSTRUMENT_HOST_ID = LRO

INSTRUMENT_NAME = "MINI-RF LRO"

INSTRUMENT_ID = MRFLRO

TARGET_NAME = MOON

SOURCE_PRODUCT_ID = {"LRO_SCLK_20100202_00.TSC","naif0009.tls"}

START_TIME = 2009-10-17T14:25:53.362224

STOP_TIME = 2009-10-17T14:27:42.2187

SPACECRAFT_CLOCK_START_COUNT = "UNK"

SPACECRAFT_CLOCK_STOP_COUNT = "UNK"

ORBIT_NUMBER = 1408

CENTER_FREQUENCY = 2380000086.11031818<Hz>

INCIDENCE_ANGLE = 53.61261526<deg>

INSTRUMENT_MODE_ID = "ZOOM_S"

INSTRUMENT_MODE_DESC = "SAR"

SOFTWARE_NAME = "Ortho"

SOFTWARE_VERSION_ID = "9.0.320"

LOOK_DIRECTION = LEFT

DESCRIPTION = "Mini-RF Level 2 SAR Calibrated Data Record

(CDR) file. The Level 2 data products are orthorectified and are re-sampled

into oblique cylindrical map projected SAR images."

/* Data Object Description. */

OBJECT = IMAGE

NAME = "MINI-RF SAR DATA"

LINES = 23616

LINE_SAMPLES = 1707

SAMPLE_TYPE = PC_REAL

SAMPLE_BITS = 32

MINIMUM = 0.000000000

MAXIMUM = 7.224467278

MEAN = 0.294667579

STANDARD_DEVIATION = 0.010913741

SCALED_PIXEL_HEIGHT = 7.4<m/pixel>

SCALED_PIXEL_WIDTH = 7.4<m/pixel>

LRO:AZIMUTH_RESOLUTION = 15.674092

LRO:RANGE_RESOLUTION = 30.486847

LINE_EXPOSURE_DURATION = 0.004609439305

BANDS = 4

BAND_STORAGE_TYPE = SAMPLE_INTERLEAVED

BAND_NAME = ("H RECEIVE INTENSITY", "V RECEIVE

INTENSITY", "CROSS POWER INTENSITY (REAL)","CROSS POWER INTENSITY

(IMAGINARY)")

DESCRIPTION = "This image contains multi-valued pixels.

The ground range detected cross-product polarimetric image file resampled

into an oblique cylindrical map projection. Each pixel is represented by

two 4-byte floating point values and an 8-byte complex value (one 4-byte

floating point real and one 4-byte floating point imaginary component) for

a total of 16 bytes per pixel. The first two numbers are the intensity

images for H and V receive, respectively. The complex value is the cross

power intensity image between the H and V receive."

END_OBJECT = IMAGE

/* Map Projection Information. */

OBJECT = IMAGE_MAP_PROJECTION

^DATA_SET_MAP_PROJECTION = "DSMAP.CAT"

POSITIVE_LONGITUDE_DIRECTION = "EAST"

KEYWORD_LATITUDE_TYPE = "PLANETOCENTRIC"

COORDINATE_SYSTEM_NAME = "PLANETOCENTRIC"

COORDINATE_SYSTEM_TYPE = "BODY-FIXED ROTATING"

LINE_FIRST_PIXEL = 1

SAMPLE_FIRST_PIXEL = 1

FIRST_STANDARD_PARALLEL = "N/A"

SECOND_STANDARD_PARALLEL = "N/A"

A_AXIS_RADIUS = 1737.4<km>

B_AXIS_RADIUS = 1737.4<km>

C_AXIS_RADIUS = 1737.4<km>

LINE_LAST_PIXEL = 23616

SAMPLE_LAST_PIXEL = 1707

LINE_PROJECTION_OFFSET = 11600.9521456

SAMPLE_PROJECTION_OFFSET = -6310.44370744

MAP_PROJECTION_TYPE = "OBLIQUE CYLINDRICAL"

MAP_PROJECTION_ROTATION = 90.0<deg>

MAP_RESOLUTION = 4096.08934062<pix/deg>

MAP_SCALE = 0.0074030002528<km/pix>

CENTER_LATITUDE = 0.0<deg>

CENTER_LONGITUDE = 0.0<deg>

REFERENCE_LATITUDE = 32.2468226517

REFERENCE_LONGITUDE = -178.075208329

MAXIMUM_LATITUDE = 35.146367<deg>

MINIMUM_LATITUDE = 29.373408<deg>

WESTERNMOST_LONGITUDE = 354.917237<deg>

EASTERNMOST_LONGITUDE = 355.623363<deg>

OBLIQUE_PROJ_POLE_LATITUDE = -0.572471<deg>

OBLIQUE_PROJ_POLE_LONGITUDE = -92.285964<deg>

OBLIQUE_PROJ_POLE_ROTATION = 122.248627<deg>

OBLIQUE_PROJ_X_AXIS_VECTOR = (-0.845280,-0.028407,0.533568)

OBLIQUE_PROJ_Y_AXIS_VECTOR = (0.532833,0.029727,0.845698)

OBLIQUE_PROJ_Z_AXIS_VECTOR = (-0.039885,0.999154,-0.009991)

END_OBJECT = IMAGE_MAP_PROJECTION

/* Metadata Associated with the Image. */

OBJECT = PARAMETER_FILE

^TEXT = "LSZ_01408_2CD_OKU_32N355_V1.TXT"

RECORD_TYPE = STREAM

FILE_RECORDS = 1872

OBJECT = TEXT

PUBLICATION_DATE = 2010-02-05

NOTE = "A parameter file generated by the SAR

data processor."

END_OBJECT = TEXT

END_OBJECT = PARAMETER_FILE

END

The above example is for a Level 2 map product in oblique cylindrical projection. Polar images are in this projection. Non-polar images are provided in equirectangular projection and have a slightly different label.

4.8.2.4    Example PDS Daughter Product Label

PDS_VERSION_ID = PDS3

LABEL_REVISION_NOTE = "2010-JHU/APL Mini-RF LRO Ver. 1"

NOTE = "Mini-RF LRO circular polarization ratio

product."

^IMAGE = "LSZ_01408_2CP_EKU_32N355_V1.IMG"

RECORD_TYPE = FIXED_LENGTH

RECORD_BYTES = 5788

FILE_RECORDS = 11823

DATA_SET_ID = "LRO-L-MRFLRO-5-CDR-MAP-V1.0"

DATA_SET_NAME = "LRO MOON MINI-RF 5 MAP-PROJECTED CALIBRATED

DATA REC V1.0"

PRODUCER_ID = "JHUAPL"

PRODUCER_FULL_NAME = "MINI-RF POC TEAM"

PRODUCER_INSTITUTION_NAME = "JOHNS HOPKINS UNIVERSITY APPLIED PHYSICS

LABORATORY"

PRODUCT_ID = "LSZ_01408_2CP_EKU_32N355_V1"

PRODUCT_VERSION_ID = "1.0"

ORIGINAL_PRODUCT_ID = "

PacketsFrom2009290_20091017_142550_20100115_214904.000.ortho_OC"

MISSION_PHASE_NAME = "NOMINAL MISSION"

PRODUCT_CREATION_TIME = 2010-02-19T21:49:34

RELEASE_ID = "0001"

MISSION_NAME = "LUNAR RECONNAISSANCE ORBITER"

INSTRUMENT_HOST_NAME = "LUNAR RECONNAISSANCE ORBITER"

INSTRUMENT_HOST_ID = LRO

INSTRUMENT_NAME = "MINI-RF LRO"

INSTRUMENT_ID = MRFLRO

TARGET_NAME = MOON

SOURCE_PRODUCT_ID = TBD

START_TIME = 2009-10-17T14:25:53.362224

STOP_TIME = 2009-10-17T14:27:42.2187

SPACECRAFT_CLOCK_START_COUNT = "UNK"

SPACECRAFT_CLOCK_STOP_COUNT = "UNK"

ORBIT_NUMBER = 1408

CENTER_FREQUENCY = 2380000086.11031818<Hz>

INCIDENCE_ANGLE = 53.61261526<deg>

INSTRUMENT_MODE_ID = "ZOOM_S"

INSTRUMENT_MODE_DESC = "SAR"

SOFTWARE_NAME = "ISIS"

SOFTWARE_VERSION_ID = "3.1.21 | 2009-09-16"

LOOK_DIRECTION = LEFT

DESCRIPTION = "This dimensionless parameter is the ratio

of the same sense circular polarization to the opposite sense circular

polarization (CPR = SC / OS). The average CPR value of the entire lunar

surface is on the order of 0.3. Certain types of surface deposits can have

either anomalously low (near zero) or anomalously high (>1.0) values."

/* Data Object Description. */

OBJECT = IMAGE

LINES = 11823

LINE_SAMPLES = 1447

BANDS = 1

BAND_STORAGE_TYPE = BAND_SEQUENTIAL

OFFSET = 0.0

SCALING_FACTOR = 1.0

SAMPLE_BITS = 32

SAMPLE_BIT_MASK = 2#11111111111111111111111111111111#

SAMPLE_TYPE = PC_REAL

CORE_NULL = 16#FF7FFFFB#

CORE_LOW_REPR_SATURATION = 16#FF7FFFFC#

CORE_LOW_INSTR_SATURATION = 16#FF7FFFFD#

CORE_HIGH_REPR_SATURATION = 16#FF7FFFFF#

CORE_HIGH_INSTR_SATURATION = 16#FF7FFFFE#

END_OBJECT = IMAGE

OBJECT = IMAGE_MAP_PROJECTION

^DATA_SET_MAP_PROJECTION = "DSMAP.CAT"

COORDINATE_SYSTEM_TYPE = "BODY-FIXED ROTATING"

MAP_PROJECTION_TYPE = "EQUIRECTANGULAR"

A_AXIS_RADIUS = 1737.4 <km>

B_AXIS_RADIUS = 1737.4 <km>

C_AXIS_RADIUS = 1737.4 <km>

FIRST_STANDARD_PARALLEL = "N/A"

SECOND_STANDARD_PARALLEL = "N/A"

COORDINATE_SYSTEM_NAME = PLANETOCENTRIC

POSITIVE_LONGITUDE_DIRECTION = EAST

KEYWORD_LATITUDE_TYPE = PLANETOCENTRIC

CENTER_LATITUDE = 0.0 <deg>

CENTER_LONGITUDE = 180.0 <deg>

LINE_FIRST_PIXEL = 1

LINE_LAST_PIXEL = 11823

SAMPLE_FIRST_PIXEL = 1

SAMPLE_LAST_PIXEL = 1447

MAP_PROJECTION_ROTATION = 0.0 <deg>

MAP_RESOLUTION = 2048.0 <pix/deg>

MAP_SCALE = 14.806323449292 <m/pixel>

MAXIMUM_LATITUDE = 35.146367 <deg>

MINIMUM_LATITUDE = 29.373408 <deg>

EASTERNMOST_LONGITUDE = 355.623363 <deg>

WESTERNMOST_LONGITUDE = 354.917237 <deg>

LINE_PROJECTION_OFFSET = 71980.499999997 <pixel>

SAMPLE_PROJECTION_OFFSET = -358229.5 <pixel>

END_OBJECT = IMAGE_MAP_PROJECTION

END

The above example is for a circular polarization ratio (CPR) product. SSP, OSP, and stokes parameter product labels are similar.

4.8.2.5    Example PDS label for a LRO Level 3 SAR Data Product

An example of a PDS label for the ISIS-generated mosaics is provided below. Right or left looking is relative to north. ORBIT_NUMBER contains the number of the first image used to make the mosaic.

PDS_VERSION_ID = PDS3

LABEL_REVISION_NOTE = "2008-JHU/APL Sample to PDS March 2008"

/* File Identification and Structures. */

RECORD_TYPE = FIXED_LENGTH

RECORD_BYTES = 32444

FILE_RECORDS = 8111

/* Pointer to data object. */

^IMAGE = "LSZ_3SC_PLU_90N000_00752_V1.IMG"

/* Identification Data Elements. */

DATA_SET_ID = "LRO-L-MRFLRO-5-CDR-MOSAIC-V1.0"

DATA_SET_NAME = "LRO MOON MINI-RF 5 POLAR MOSAIC CALIBRATED

DATA REC V1.0"

PRODUCER_ID = "JHUAPL"

PRODUCER_FULL_NAME = "MINI-RF POC TEAM"

PRODUCER_INSTITUTION_NAME = "JOHNS HOPKINS UNIVERSITY APPLIED PHYSICS

LABORATORY"

PRODUCT_ID = "LSZ_3SC_PLU_90N000_00752_V1"

PRODUCT_VERSION_ID = "1.0"

PRODUCT_CREATION_TIME = 2008-01-02T20:37:30

RELEASE_ID = "0001"

MISSION_NAME = "LUNAR RECONNAISSANCE ORBITER"

INSTRUMENT_HOST_NAME = "LUNAR RECONNAISSANCE ORBITER"

INSTRUMENT_HOST_ID = LRO

INSTRUMENT_NAME = "MINI-RF LRO"

INSTRUMENT_ID = MRFLRO

TARGET_NAME = MOON

START_TIME = 2007-10-31T17:52:06.798338

STOP_TIME = 2007-10-31T17:53:22.3410

SPACECRAFT_CLOCK_START_COUNT = "1/1234567:123"

SPACECRAFT_CLOCK_STOP_COUNT = "1/1234567:123"

ORBIT_NUMBER = 300

INCIDENCE_ANGLE = "N/A"

INSTRUMENT_MODE_ID = "N/A"

INSTRUMENT_MODE_DESC = "N/A"

SOFTWARE_NAME = "ISIS"

SOFTWARE_VERSION_ID = "3.1.14"

LOOK_DIRECTION = "N/A"

DESCRIPTION = "

Polar mosaic made from Mini-RF Level 2 SAR Calibrated Data Record (CDR) files."

/* Data Object Description. */

OBJECT = IMAGE

NAME = "MINI-RF SAR DATA"

LINES = 8111

LINE_SAMPLES = 8111

SAMPLE_TYPE = PC_REAL

SAMPLE_BITS = 32

MINIMUM = "N/A"

MAXIMUM = "N/A"

MEAN = "N/A"

STANDARD_DEVIATION = "N/A"

SCALED_PIXEL_HEIGHT = "N/A"

SCALED_PIXEL_WIDTH = "N/A"

AZIMUTH_RESOLUTION = "N/A"

RANGE_RESOLUTION = "N/A"

BANDS = 1

BAND_STORAGE_TYPE = BAND_SEQUENTIAL

BAND_NAME = "SAME SENSE POLARIZATION"

DESCRIPTION = "

This mosaic covers the north polar region of the Moon and

consists of strips of same sense polarization data."

END_OBJECT = IMAGE

OBJECT = IMAGE_MAP_PROJECTION

^DATA_SET_MAP_PROJECTION = "DSMAP.CAT"

COORDINATE_SYSTEM_TYPE = "BODY-FIXED ROTATING"

MAP_PROJECTION_TYPE = "POLAR STEREOGRAPHIC"

A_AXIS_RADIUS = 1738.100000 <KM>

B_AXIS_RADIUS = 1738.100000 <KM>

C_AXIS_RADIUS = 1738.100000 <KM>

FIRST_STANDARD_PARALLEL = "N/A"

SECOND_STANDARD_PARALLEL = "N/A"

COORDINATE_SYSTEM_NAME = PLANETOCENTRIC

POSITIVE_LONGITUDE_DIRECTION = EAST

KEYWORD_LATITUDE_TYPE = PLANETOCENTRIC

/* NOTE: CENTER_LATITUDE and CENTER_LONGITUDE describe */

/* the location of the center of projection, which is not */

/* necessarily equal to the location of the center point */

/* of the file. */

CENTER_LATITUDE = 90.000000 <DEG>

CENTER_LONGITUDE = 0.000000 <DEG>

REFERENCE_LATITUDE = "N/A"

REFERENCE_LONGITUDE = "N/A"

LINE_FIRST_PIXEL = 1

LINE_LAST_PIXEL = 8111

SAMPLE_FIRST_PIXEL = 1

SAMPLE_LAST_PIXEL = 8111

MAP_PROJECTION_ROTATION = 0.000000

MAP_RESOLUTION = 404.474236 <PIX/DEG>

MAP_SCALE = 0.075000 <KM/PIX>

MAXIMUM_LATITUDE = 90.000000 <DEG>

MINIMUM_LATITUDE = 80.000000 <DEG>

EASTERNMOST_LONGITUDE = 360.000000 <DEG>

WESTERNMOST_LONGITUDE = 0.000000 <DEG>

LINE_PROJECTION_OFFSET = 4055.000000

SAMPLE_PROJECTION_OFFSET = 4055.000000

END_OBJECT = IMAGE_MAP_PROJECTION

END

5.    Applicable Software

5.1    Software Distribution And Update Procedures

The LRO Mini-RF delivery to the PDS does not include software.

6.    Appendices

6.1    Level 3+ Derived Data Record (DDR) Products

Sandia National Laboratories will produce a tool that generates topography from the continuous mode SAR data to be acquired by Mini-RF on LRO.  They will use as input the SAR strips that have been processed by the Vexcel SAR processor.  Additionally Sandia will need to provide the viewing geometry limits that are needed in order for their tool to be able to generate topography.  This will affect targeting, as APL will need to acquire strips that are applicable for SAR stereo processing.

The output from the SAR stereo processor will be strips showing lunar topography.  These strips will have pixel values that either show lunar radius, or an altitude relative to a stated datum.  The strips will be in a polar stereographic projection for regions poleward of 80°.  If any equatorial data is acquired then the topographic strips will be in a simple cylindrical projection. Table 18 below describes these products.

Sandia will deliver both the processing tool as well as generate the image products and deliver them too.  It is envisioned that some training will be required on how to use the tool.

Table 18 The SAR Stereo product file description (DATASET_ID: LRO-L-MRFLRO-5-CDR-STEREO-V n.n).

Table 19 below describes the SAR Stereo Parameter file.  This file shall be an ASCII text file where the text is in a parameter name-value comma-separated value form.  The columns shall be comma delimited and the records are of fixed-length.

Table 19 The contents of the SAR Stereo Parameter file. The size of the image file in bytes should equal: (Line Length) * (Number of Lines) * (4 bytes/pixel).

Table 20 Sample contents of a Sandia SAR Stereo parameter file. Note that all string values are quoted and space-padded for constant field length.

6.1.1.1    SAR Stereo File Naming

The following table describes the detailed naming convention for this dataset.  These products are composed of two strips.  They contain data from two orbits.

The filenames of these products will follow the convention described in sec. 4.7.1 except that the center latitude and longitude given in their file names are that of the center of the image and the orbit number is that of the highest orbit number product among the lower-level products used in the product :

The following is an example file name of a Mini-RF LRO SAR stereo product, S-band, interferometric, level 3, calibrated data record, 512 ppd resolution, unnormalized floating point format, center coordinates 82ºN, 231º, highest orbit number 617, version 1.

LSI_3CD_XLU_82N231_00617_V1.IMG

It would be accompanied by the following metadata parameter file:

LSI_3CD_XLU_82N231_00617_V1.CSV

6.2    Glossary

6.3    Acronyms

APL               (The Johns Hopkins University) Applied Physics Laboratory

ASCII               American Standard Code for Information Interchange

CCSDS             Consultative Committee for Space Data Systems

CDR                 Calibrated Data Record

CK                   Camera-Matrix Kernel (SPICE)

CLM                 Chandrayaan-1 Lunar Module

CODMAC           Committee on Data Management and Computation

CPR                 Circular Polarization Ratio

CSV                  Comma-Separated Values

DEM                 Digital Elevation Model

dB                    Decibels

DDR                 Derived Data Record

EDR                 Experimental Data Record

GSFC               Goddard Space Flight Center

kHz                  Kilohertz

I&T                   Integration and Test

IK                     Instrument Measurement Kernel (SPICE)

ISIS                  Integrated Software for Imaging Spectrometers

ISRO                Indian Space Research Organisation

JHU/APL           The Johns Hopkins University Applied Physics Laboratory

K                      Kelvin

km                    Kilometers

LCP                  Left Circular Polarized

LSK                  Leap seconds Kernel (SPICE)

m                     Meters

m/s                   Meters per second

ms                    Microseconds (10^-6 seconds)

LRO                 Lunar Reconnaissance Orbiter

MET                  Mission Elapsed Time

NAIF                 Navigation and Ancillary Information Facility

NASA                National Aeronautics and Space Administration

NAWC               Naval Air Warfare Center

ns                    Nanoseconds (10^-9 seconds)

ODL                 Object Description Language

OSP                  Opposite Sense Polarization

PDF                  (Adobe) Portable Document Format

PDR                 Packetized Data Records

PDS                  (NASA) Planetary Data System

POC                 Payload Operations Center

PVL                  Parameter Value Language

RCP                 Right Circular Polarized

RDR                 Reduced Data Records

SAR                  Synthetic Aperture Radar

SCLK               Spacecraft Clock Kernel (SPICE)

SSP                  Same Sense Polarization

STF                  (Vexcel^®) SKY Telemetry Format

SPICE               Spacecraft, Planet, Instrument, C-matrix Events

SPK                  Spacecraft and Planets Kernel (SPICE)

TIFF                 Tagged Image File Format

ULCN2005        Unified Lunar Control Network 2005

USGS               United States Geological Survey

UTC                  Coordinated Universal Time

W                     Watts