urn:nasa:pds:magellan_scvdr:data_edf:edf04355 1.0 1.23.0.0 Product_Observational 2025-09-10 1.0 Initial PDS4 version 1992-03-09T01:21:45.201Z 1992-03-09T01:37:28.868Z Magellan Mission urn:nasa:pds:context:investigation:mission.magellan data_to_investigation The Magellan Spacecraft Host urn:nasa:pds:context:instrument_host:spacecraft.mgn is_instrument_host Magellan Spacecraft Radar System Instrument urn:nasa:pds:context:instrument:mgn.rdrs is_instrument Venus Planet urn:nasa:pds:context:target:planet.venus data_to_target SCVDR 1 4355 Mapping Cycle 3 mg_2145 urn:nasa:pds:magellan_scvdr:document:scvdr_sis data_to_document edf04355_1.dat 1994-10-11T06:00:47Z The Emissivity Data File (EDF) contains measurements of the microwave emissivity of the Venus surface, obtained from the radiometer mode of the Magellan radar sensor. The EDF contains a CCSD header, a keyword and value SFDU, a binary header record SFDU, and one or more binary data record SFDUs, sandwiched between starting and ending marker SFDUs.

0 20 7-Bit ASCII Text CCSD header.

20 372 7-Bit ASCII Text SFDU keyword label (K-type).

Emissivity Header Table 392 1 The single binary EDF header record contains constants that describe the radiometry data reduction process, the algorithm IDs, and planetary parameters. 29 1 92 SFDU_AGGREGATE_HEADER 1 1 ASCII_String 20 'NJPL1I00002100000072', the number '0021' is registered with the NJPL SFDU authority as the 'Emissivity Header Record'. The '00000072' signifies that the remainder of the SFDU is 72 bytes in length. ORBIT_NUMBER 2 21 UnsignedMSB4 4 The Magellan orbit number for the data represented in these data records. VERSION_NUMBER 3 25 UnsignedMSB4 4 The orbit version number for these data. Obtained from the VERSION_ID keyword of the corresponding C-BIDR Orbit Header File (Note: This turns out not to be a good indicator of the version of the data file; the Orbit Header File itself is rarely updated). RADI_MAJOR_VERSION_NUMBER 4 29 UnsignedMSB2 2 The number of the major software version of Stanford program RADI used to process these data. RADI_MINOR_VERSION_NUMBER 5 31 UnsignedMSB2 2 The number of the minor software version of Stanford program RADI used to process these data. NUMBER_OF_DATA_RECORDS 6 33 UnsignedMSB4 4 The number of emissivity records in this file. RADP_MAJOR_VERSION_NUMBER 7 37 UnsignedMSB2 2 The number of the major software version of Stanford program RADP used to process these data. RADP_MINOR_VERSION_NUMBER 8 39 UnsignedMSB2 2 The number of the minor software version of Stanford program RADP used to process these data. ENGEX_MAJOR_VERSION_NUMBER 9 41 UnsignedMSB2 2 The number of the major software version of Stanford program ENGEX used to process these data. ENGEX_MINOR_VERSION_NUMBER 10 43 UnsignedMSB2 2 The number of the minor software version of Stanford program ENGEX used to process these data. SABEX_MAJOR_VERSION_NUMBER 11 45 UnsignedMSB2 2 The number of the major software version of Stanford program SABEX used to process these data. SABEX_MINOR_VERSION_NUMBER 12 47 UnsignedMSB2 2 The number of the minor software version of Stanford program SABEX used to process these data. RCOMP_MAJOR_VERSION_NUMBER 13 49 UnsignedMSB2 2 The number of the major software version of Stanford program RCOMP used to process these data. RCOMP_MINOR_VERSION_NUMBER 14 51 UnsignedMSB2 2 The number of the minor software version of Stanford program RCOMP used to process these data. RADIATIVE_TRANSFER_MODEL_ID 15 53 UnsignedMSB2 2 The number of the major software version of Stanford program RATM used to process these data. QUATERNION_COMPUTATION_METHOD 16 55 UnsignedByte 1 The code number for the specific method for determining the quaternion correction (if any; see Section 5.7 of the SCVDR SIS). TSKY_COMPUTATION_METHOD 17 56 UnsignedByte 1 The code number for the specific method for determining sky temperature as seen at the surface of Venus (see Section 5.7 of the SCVDR SIS). VENUS_DISK_BRIGHTNESS_COMP_METHOD 18 57 UnsignedByte 1 The code number for the specific method of determining the effective global temperature of Venus as seen at the spacecraft (see Section 5.7 of the SCVDR SIS). BEAM_EFFICIENCY_COMP_METHOD 19 58 UnsignedByte 1 The code number for the specific method of determining high-gain antenna beam efficiency (see Section 5.7 of the SCVDR SIS). REFLECTIVITY_COMP_METHOD 20 59 UnsignedByte 1 The code number for the specific method for estimating the surface Fresnel reflectivity appropriate for the sky brightness reflection at the surface (see Section 5.7 of the SCVDR SIS). VARIANCE_ESTIMATION_COMP_METHOD 21 60 UnsignedByte 1 The code number for the specific method of determining the variance expected in the estimates of Venus surface brightness and emissivity (see Section 5.7 of the SCVDR SIS). SYSTEMATIC_ERROR_CORRECTION_METHOD 22 61 UnsignedByte 1 The code number for the specific method for correcting the radiometry signal for systematic effects (such as capacitive discharge associated with altimeter bursts; see Section 5.7 of the SCVDR SIS). GEOMETRY_COMPUTATION_METHOD 23 62 UnsignedByte 1 The code number for the specific method for computing the spacecraft position, velocity and orientation (see Section 5.7 of the SCVDR SIS). SOURCE_OF_TELEMETRY_INFO 24 63 UnsignedByte 1 The code number for the specific method for computing and conditioning the spacecraft telemetry signals (see Section 5.7 of the SCVDR SIS). SPARE 25 64 UnsignedByte 1 Spare. VENUS_TEMPERATURE 26 65 IEEE754MSBSingle 4 K The effective (global) brightness temperature of Venus as seen at the spacecraft (nominally 635K). COSMIC_BACKGROUND_TEMPERATURE 27 69 IEEE754MSBSingle 4 K The cosmic background temperature (nominally 3K) for emissivity measurements at Venus. BEAM_EFFICIENCY 28 73 IEEE754MSBSingle 4 The high-gain antenna beam efficiency used for interpreting emissivity measurements (nominally 0.8). ANTENNA_RADIATION_EFFICIENCY 29 77 IEEE754MSBSingle 4 The high-gain antenna radiation efficiency used for interpreting emissivity measurements (nominally 0.977). 1 12 1 0 81 12 SPARE 1 1 UnsignedByte 1 Spare. Emissivity Data Table 572 1062 Each fixed length EDF data record contains the result of processing a pair of measurements made by the radiometric mode of the Magellan radar system, one in which the receiver was coupled to the high gain antenna, the other to a load at a known temperature. The difference between these values is used to derive the surface microwave brightness, and hence its emissivity. 32 10 240 SFDU_AGGREGATE_HEADER 1 1 ASCII_String 20 'NJPL1I00002200000220', the number '0022' is registered with the NJPL SFDU authority as the 'Emissivity Data Record'. The final '00000220' signifies that the remainder of the SFDU is 220 bytes in length. FOOTPRINT_NUMBER 2 21 UnsignedMSB4 4 Starting from 1, the number of the Emissivity Data Record by increasing emissivity footprint time (S_C_EMISSIVITY_EPOCH), starting at 1. SAB_NUMBER 3 25 UnsignedMSB4 4 The number assigned to the burst header that contains the antenna measurement (as opposed to the calibration measurement) referenced by this Stanford emissivity data record. FLAGS 4 29 UnsignedMSB4 4 Stanford Emissivity Data Record Flag Values (see Table 5-16 of the SCVDR SIS). S_C_EMISSIVITY_EPOCH 5 33 IEEE754MSBDouble 8 second The ephemeris time (seconds of TDB since J2000) at which the emissivity measurement was made. 1 3 1 0 41 12 S_C_POSITION_VECTOR 1 1 IEEE754MSBSingle 4 km The S/C position at S_C_EMISSIVITY_EPOCH, relative to the Venus center of mass, expressed in inertial coordinates. 2 3 1 0 53 12 ALTIMETER_POINTING_VECTOR 1 1 IEEE754MSBSingle 4 The altimetry antenna pointing vector at S_C_EMISSIVITY_EPOCH expressed as a unit vector in inertial coordinates. 3 3 1 0 65 12 SAR_POINTING_VECTOR 1 1 IEEE754MSBSingle 4 The HGA pointing vector at S/C_EMISSIVITY_EPOCH, expressed as a unit vector in inertial coordinates. FOOTPRINT_LATITUDE 6 77 IEEE754MSBSingle 4 degree The body-fixed latitude, at S_C_EMISSIVITY_EPOCH, of the boresight intercept point (obtained from the C-BIDR Processing Parameters file). FOOTPRINT_LONGITUDE 7 81 IEEE754MSBSingle 4 degree The body-fixed longitude, at S/C_EMISSIVITY_EPOCH, of the boresight intercept point (obtained from the C-BIDR Processing Parameters file). AZIMUTH_FROM_FOOTPRINT_TO_S_C 8 85 IEEE754MSBSingle 4 degree At (FOOTPRINT_LATITUDE, FOOTPRINT_LONGITUDE) the spacecraft azimuth measured positive toward the east from local north. POLARIZATION 9 89 ASCII_String 2 Horizontal received ('HH') or vertical received ('VV'). 4 2 1 0 91 2 SPARE 1 1 UnsignedByte 1 Spare. FOOTPRINT_PLANETARY_RADIUS 10 93 IEEE754MSBSingle 4 km The estimated planetary radius at the boresight intercept point (obtained from the C-BIDR Processing Parameters file). FOOTPRINT_INCIDENCE_ANGLE 11 97 IEEE754MSBSingle 4 degree The incidence angle at the boresight intercept point (obtained from the C-BIDR Processing Parameters file). 5 10 1 0 101 10 SAR_STATUS_FOR_PRECEDING_BURST 1 1 UnsignedByte 1 The original SAB header status field from the burst preceding the Antenna Measurement, of interest because the Antenna Measurement actually occurs during this burst. 6 10 1 0 111 10 SAR_STATUS_FOR_ANTENNA_BURST 1 1 UnsignedByte 1 The original SAB header status field used for the radiometry (emissivity) measurement. 7 10 1 0 121 10 SAR_STATUS_FOR_CALIBRATION_BURST 1 1 UnsignedByte 1 The original SAB header status field used for the radiometry (emissivity) calibration. TRANSMITTER_A_FLAG 12 131 UnsignedByte 1 If set (1), transmitter A was active; if not set (0) transmitter B was active. RECEIVER_A_FLAG 13 132 UnsignedByte 1 If set (1), receiver A was active; if not set (0), receiver B was active. ONU_A_FLAG 14 133 UnsignedByte 1 If set (1), ONU A was active; if not set (0), ONU B was active. 8 3 1 0 134 3 SPARE 1 1 UnsignedByte 1 Spare. CALIBRATED_RADIOMETRY_SIGNAL 15 137 IEEE754MSBSingle 4 The difference between the antenna radiometry (emissivity) measurement ANT and the calibration measurement COMPENSATED_CALIB_MEASUREMENT (CALIBRATED_RADIOMETRY_SIGNAL = ANT - COMPENSATED_CALIB_MEASUREMENT), in units of radiometer counts. This value has been corrected for non-systematic radiometric effects, but has not been corrected for systematic errors. CORRECTED_RADIOMETRY_SIGNAL 16 141 IEEE754MSBSingle 4 The radiometer signal after correction for systematic errors in units of radiometer counts. COMPENSATED_CALIB_MEASUREMENT 17 145 IEEE754MSBSingle 4 The radiometer measurement when it is connected to the reference load, in units of radiometer counts. This value has been corrected for non-systematic radiometric effects. RECEIVER_PHYSICAL_TEMPERATURE 18 149 IEEE754MSBSingle 4 K The physical temperature of the SAR receiver as reported from telemetry in image Processing Parameter files. SENSOR_INPUT_NOISE_TEMPERATURE 19 153 IEEE754MSBSingle 4 K The system temperature of the sensor RF input port, obtained from the radiometry (emissivity) signal and compensated for receiver gain and temperature. 9 5 1 0 157 20 CABLE_TEMPERATURE_SENSORS 1 1 IEEE754MSBSingle 4 K The physical temperatures reported by five sensors along the cable between the antenna and the receiver front end. HGA_ANTENNA_NOISE_TEMPERATURE 20 177 IEEE754MSBSingle 4 K The system temperature of the HGA antenna, determined from the sensor input noise temperature and the loss and physical temperature of the HGA cable. HGA_REFLECTOR_PHYSICAL_TEMP 21 181 IEEE754MSBSingle 4 K High gain antenna physical temperature obtained from engineering telemetry channel E-0100. S_BAND_FEED_PHYSICAL_TEMP 22 185 IEEE754MSBSingle 4 K S-Band feed physical temperature obtained from engineering telemetry channel E-0098. REFLECTED_SKY_TEMPERATURE 23 189 IEEE754MSBSingle 4 K The sky brightness in the forward scatter (specular) direction, nominally equal to COSMIC_BACKGROUND_TEMPERATURE but computed according to TSKY_COMPUTATION_METHOD. SOLID_ANGLE_SUBTENDED_BY_VENUS 24 193 IEEE754MSBSingle 4 radian The solid angle subtended by the Venus disk at the spacecraft. ONE_WAY_TRANSMISSION_RAY_PATH_TO_BIP 25 197 IEEE754MSBSingle 4 The one-way power transmission factor for the atmosphere between the point at (FOOTPRINT_LATITUDE, FOOTPRINT_LONGITUDE, FOOTPRINT_PLANETARY_RADIUS) and the spacecraft using the atmospheric model. SURFACE_PHYSICAL_TEMP 26 201 IEEE754MSBSingle 4 K The physical temperature of the surface obtained from the assumed radius at the boresight intercept point (FOOTPRINT_PLANETARY_RADIUS) and the (Magellan-adopted) model for atmospheric structure. UPWELLING_ATMOSPHERIC_EMISSION_T 27 205 IEEE754MSBSingle 4 K The effective temperature of the atmosphere resulting from self-emission along the ray path determined by the HGA. DOWNWELLING_ATMOSPHERIC_EMISSION_T 28 209 IEEE754MSBSingle 4 K The effective temperature of the atmosphere observed at the surface along an incoming ray that, after specular reflection from the (average) spherical surface, would reach the spacecraft. DOWNWELLING_ATMOSPHERIC_EMISSION_T 29 213 IEEE754MSBSingle 4 K The brightness temperature of the Venus surface derived from the radiometry (emissivity) measurements. SURFACE_BRIGHTNESS_TEMP_VARIANCE 30 217 IEEE754MSBSingle 4 Variance of the derived Venus brightness temperature using the method identified by VARIANCE_ESTIMATION_COMP_METHOD. EMISSIVITY 31 221 IEEE754MSBSingle 4 The emissivity of the Venus surface. EMISSIVITY_VARIANCE 32 225 IEEE754MSBSingle 4 Variance of the derived emissivity using the method identified by VARIANCE_ESTIMATION_COMP_METHOD. 10 12 1 0 229 12 SPARE 1 1 UnsignedByte 1 Spare.