PDS_VERSION_ID        = PDS3
RECORD_TYPE           = STREAM

OBJECT                = TEXT
   PUBLICATION_DATE    = 2007-09-08
   NOTE                = "Description of contents of BROWSE directory"
END_OBJECT            = TEXT
END

EDR browse products are organized into subdirectories in a structure that 
parallels that of the EDR directory. That is, by year and DOY, e.g.
2006/2006_350, with subdirectories for each observation named for the
combination of class type and observation ID unique to a single observation,
e.g. "FRT00001270". 

In the subdirectory for the observation, there are two types of products. One 
is an HTML file that gives the key parameters of the component EDRs and links 
to PNG files for each EDR. A detached label to the HTML file describes the 
observation at a high level.

The browse product fro each EDR is a scaled (0-255), median DN value from 
selected wavelengths for each spatial element in an EDR multiband image, 
stored in PNG format. A detached label to the PNG file describes the source 
EDR and the scaling between its raw data values and the PNG file.

The file naming convention for the HTML browse products is as follows.
(ClassType)(ObsID)_BROWSE_EDR(version).(Ext)
where:
Class Type = 
    FRT (Full Resolution Targeted Observation)
    HRL (Half Resolution Long Targeted Observation)
    HRS (Half Resolution Short Targeted Observation)
    ASE (Atmospheric Survey EPF)
    MSS (Multispectral Survey, lossy compressed)
    MSP (Multispectral Survey, losslessly compressed)
    MSW (Multispectral Window)
    CAL (Radiometric Calibration)
    FFC (Flat Field Calibration)
    ICL (Calibration source intercalibration)
    STO (Star Observation)
    FUN (Functional test)
    UNK (no valid EDRs within observation that indicate class type)
ObsID=    nnnnnnnn, Observation ID, unique for the whole CRISM mission, 
expressed as a hexadecimal number
version=    0, 1,...,9, a, ..., z
Ext= HTML

The file naming convention for the PNG browse products is as follows. 
(ClassType)(ObsID)_(Counter)_ (Activity)(SensorID)_RAW(version).(Ext)
where:
Counter= nn, a monotonically increasing ordinal counter of EDRs from one 
Observation ID 
Activity= for an EDR, type of observation, e.g. 
    BInnn - Bias measurements / Macro#
    DFnnn - Dark field measurements / Macro#
    LPnnn - Lamp measurements / Macro #
    SPnnn - Sphere measurements / Macro #
    SCnnn - Scene measurements / Macro #
    T1nnn - Focal plane electronics test pattern 1 / Macro #
    T2nnn - Focal plane electronics test pattern 2 / Macro #
    T3nnn - Focal plane electronics test pattern 3 / Macro #
    T4nnn - Focal plane electronics test pattern 4 / Macro #
    T5nnn - Focal plane electronics test pattern 5 / Macro #
    T6nnn - Focal plane electronics test pattern 6 / Macro #
    T7nnn - Focal plane electronics test pattern 7 / Macro #
    UNnnn - Instrument configuration does not match macro library / Macro #
Sensor ID= S for VNIR, or L for IR
version=    0, 1,...,9, a, ..., z
Ext= PNG