OBJECT = COLUMN NAME = SFDU_LABEL_AND_LENGTH START_BYTE = 1 DATA_TYPE = CHARACTER BYTES = 20 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_SFDU USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The SFDU_label_and_length element identifies the label and length of the Standard Format Data Unit (SFDU)." END_OBJECT OBJECT = COLUMN NAME = FOOTPRINT_NUMBER START_BYTE = 21 DATA_TYPE = LSB_INTEGER BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_NFOOT USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The footprint_number element provides a signed integer value. The altimetry and radiometry processing program assigns footprint 0 to that observed at nadir at periapsis. The remaining footprints are located along the spacecraft nadir track, with a separation that depends on the Doppler resolution of the altimeter at the epoch at which that footprint is observed. Pre-periapsis footprints will be assigned negative numbers, post-periapsis footprints will be assigned positive ones. A loss of several consecutive burst records from the ALT-EDR will result in missing footprint numbers." END_OBJECT OBJECT = COLUMN NAME = ALT_FLAG_GROUP START_BYTE = 25 DATA_TYPE = LSB_UNSIGNED_INTEGER BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_FLAG USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The ALT_FLAG_GROUP element identifies the following flag fields. AR_FIT=0x0001 Record contains footprint values that have been fitted in the altimetry and radiometry mgmtac processing phase. AR_EPHC=0x0002 Geometry values have been corrected for ephemeris errors in the mgmorb phase. AR_RHOC=0x0004 Reflectivity values have been corrected from SAR backscatter values in the mgmorb phase. AR_RS2=0x0008 Range-sharpened values have passed the 2nd-order template fitting criteria in the mgmtac phase. AR_NRS2=0x0010 Non-range-sharpened values have passed the 2nd-order template fitting criteria in the mgmtac phase. AR_BAD=0x0020 Ignore this record entirely. AR_RBAD=0x0040 Ignore the range-sharpened profile range_sharp_echo_profile[] and the associated derived_planetary_radius value. AR_CBAD=0x0080 Ignore the non_range_sharp_echo_prof[] and the associated radar_derived_surf_roughness and derived_fresnel_reflectivity values. AR_TMARK=0x0100 Temporary derived_planetary_radius marker flag, used in the mgmdqe phase. AR_CMARK=0x0200 Temporary radar_derived_surf_roughness marker flag, used in the mgmdqe phase. AR_FMARK=0x0400 Temporary derived_fresnel_reflect marker flag, used in the mgmdqe phase. AR_HAGFORS=0x0800 radar_derived_surf_roughness and its errors and correlations are expressed as Hagfors' C parameter instead of degrees of RMS slope. This flag will not be set in any standard ARCDR products. It is solely used during some phases of internal MIT processing. AR_BADALTA=0x1000 The altimetry antenna was pointed more than 5 degrees from its expected location as given by the nominal look-angle profile. AR_SLOPEBAD=0x2000 The radar_derived_surf_roughness parameter value is suspect, and non_range_sharp_echo_prof should also be disregarded. AR_RHOBAD=0x4000 The derived_fresnel_reflectivity value is suspect. AR_RAD2=0x8000 This record was created under software version 2 or higher, in which mult_peak_fresnel_reflect_corr, derived_planetary_thresh_radi, signal_quality_indicator, and derived_thresh_detector_index are significant. AR_RAD2BAD=0x10000 The derived_planetary_thresh_radi value is suspect. AR_AMBIG=0x20000 The value of derived_planetary_radius has been shifted by a multiple of the range ambiguity, (10.02 km) during the MGMDQE processing phase. AR_AMBIG2=0x40000 The value of derived_planetary_thresh_radi has been shifted by a multiple of the range ambiguity, (10.02 km) during the MGMDQE processing phase." END_OBJECT OBJECT = COLUMN NAME = ALT_FLAG2_GROUP START_BYTE = 29 DATA_TYPE = LSB_UNSIGNED_INTEGER BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_FLAG2 USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " Additional flag fields (unused)." END_OBJECT OBJECT = COLUMN NAME = ALTIMETRY_FOOTPRINT_TDB_TIME START_BYTE = 33 DATA_TYPE = VAX_REAL BYTES = 8 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_SCET USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The altimetry_footprint_tdb_time element provides the value of the ephemeris time at which the spacecraft passed directly over the center of the footprint. As each footprint is composed of data collected from several altimeter bursts, this epoch doesn't necessarily coincide with a particular burst." END_OBJECT OBJECT = COLUMN NAME = ALT_SPACECRAFT_POSITION_VECTOR START_BYTE = 41 DATA_TYPE = VAX_REAL BYTES = 8 ITEMS = 3 UNIT = km OBJECT = ALIAS NAME = AR_POS USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The alt_spacecraft_position_vector element provides the value of the spacecraft position at altimetry_footprint_tdb_time, relative to the Venus center of mass, expressed in inertial coordinates in the J2000 coordinate system." END_OBJECT OBJECT = COLUMN NAME = ALT_SPACECRAFT_VELOCITY_VECTOR START_BYTE = 65 DATA_TYPE = VAX_REAL BYTES = 8 ITEMS = 3 UNIT = 'km/s' OBJECT = ALIAS NAME = AR_VEL USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The alt_spacecraft_velocity_vector element provides the spacecraft velocity at altimetry_footprint_tdb_time, relative to the Venus center of mass, expressed in inertial coordinates in the J2000 coordinate system." END_OBJECT OBJECT = COLUMN NAME = ALT_FOOTPRINT_LONGITUDE START_BYTE = 89 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = deg OBJECT = ALIAS NAME = AR_LON USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The alt_footprint_longitude (VBF85) element provides the value of the crust-fixed longitude of the center of the altimeter footprint, in the range of 0 - 360 easterly longitude. Periapsis nadir increases in longitude by about 1.48 deg per day (about 0.2 deg per orbit)." END_OBJECT OBJECT = COLUMN NAME = ALT_FOOTPRINT_LATITUDE START_BYTE = 93 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = deg OBJECT = ALIAS NAME = AR_LAT USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The alt_footprint_latitude (VBF85) element provides the value of the crust-fixed latitude of the center of the altimeter footprint, in the range of -90 (South Pole) to 90 (North Pole)." END_OBJECT OBJECT = COLUMN NAME = ALT_ALONG_TRACK_FOOTPRINT_SIZE START_BYTE = 97 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = km OBJECT = ALIAS NAME = AR_XFOOT USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The alt_along_track_footprint_size element provides the value of along-track dimension of the Venus surface area whose mean radius, RMS slope, and reflectivity are reported in this data record. The along track dimension is chosen to be the smallest multiple of the Doppler resolution of the altimeter (at this point in the spacecraft orbit) that is greater than 8 km." END_OBJECT OBJECT = COLUMN NAME = ALT_CROSS_TRACK_FOOTPRINT_SIZE START_BYTE = 101 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = km OBJECT = ALIAS NAME = AR_YFOOT USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The alt_cross_track_footprint_size element provides the value of the cross-track footprint dimension determined solely by the radar baud length and the spacecraft altitude at this point in the orbit." END_OBJECT OBJECT = COLUMN NAME = RECEIVER_NOISE_CALIBRATION START_BYTE = 105 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = 'km**2' OBJECT = ALIAS NAME = AR_RCAL USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The receiver_noise_calibration element provides the value of a measure of the altimeter noise background, obtained from the pulse- compressed altimeter signals by the mgmtac phase of the altimetry and radiometry data reduction program." END_OBJECT OBJECT = COLUMN NAME = UNCORRECTED_DISTANCE_TO_NADIR START_BYTE = 109 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = km OBJECT = ALIAS NAME = AR_RANGE USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The uncorrected_distance_to_nadir element provides the `raw' measurement of range-to-surface, obtained from the pulse-compressed altimeter signals by the MGMTAC phase of the altimetry and radiometry data reduction program." END_OBJECT OBJECT = COLUMN NAME = ATMOS_CORRECTION_TO_DISTANCE START_BYTE = 113 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = km OBJECT = ALIAS NAME = AR_ATMOS USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The atmos_correction_to_distance element provides the value of the correction applied to derived_planetary_radius to allow for the delay of signals passing through the atmosphere, calculated by the MGMOUT phase of the altimetry and radiometry data reduction program." END_OBJECT OBJECT = COLUMN NAME = DERIVED_PLANETARY_RADIUS START_BYTE = 117 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = km OBJECT = ALIAS NAME = AR_RADIUS USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The derived_planetary_radius element provides the value of the mean Venus radius for this radar footprint, obtained by subtracting (uncorrected_range_to_nadir - atmospheric_correct_to_range) from the length of the alt_spacecraft_position_vector element." END_OBJECT OBJECT = COLUMN NAME = RADAR_DERIVED_SURF_ROUGHNESS START_BYTE = 121 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = deg OBJECT = ALIAS NAME = AR_SLOPE USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The radar_derived_surf_roughness element provides the value of the root mean square meter-scale surface slope, averaged over the radar footprint, obtained by fitting the altimeter echo to a suite of theoretical templates derived from the Hagfors scattering model." END_OBJECT OBJECT = COLUMN NAME = DERIVED_FRESNEL_REFLECTIVITY START_BYTE = 125 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_RHO USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The derived_fresnel_reflectivity element provides the value of the bulk reflectivity of the surface material, averaged over the radar footprint, obtained by fitting the altimeter echo to a suite of theoretical templates derived from the Hagfors scattering model, but ignoring the effect of small-scale surface roughness." END_OBJECT OBJECT = COLUMN NAME = DERIVED_FRESNEL_REFLECT_CORR START_BYTE = 129 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_RHOCOR USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The derived_fresnel_reflect_corr element provides the value of the derived_fresnel_reflectivity correction factor for diffuse scattering which is a factor which must be added to the derived_fresnel_reflectivity (but only if the AR_RHOC flag is set in alt_flag_group), to allow for the effect of small-scale surface roughness." END_OBJECT OBJECT = COLUMN NAME = FORMAL_ERRORS_GROUP START_BYTE = 133 DATA_TYPE = VAX_REAL BYTES = 4 ITEMS = 3 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_ERROR USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The formal_errors_group element provides the value of the 1-sigma statistical errors expected in the determination of the derived_planetary_radius, the radar_derived_surf_roughness, and the derived_fresnel_reflectivity elements, respectively." END_OBJECT OBJECT = COLUMN NAME = FORMAL_CORRELATIONS_GROUP START_BYTE = 145 DATA_TYPE = VAX_REAL BYTES = 4 ITEMS = 6 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_CORREL USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The formal_correlations_group provides the formal correlations between the derived_planetary_radius and the derived_rms_surface_fresnel_reflect elements, and between the derived_fresnel_reflectivity and the derived_planetary_radius elements, respectively. As the profile fitting algorithm is non-linear, the correlations may not be symmetric." END_OBJECT OBJECT = COLUMN NAME = EPHEMERIS_RADIUS_CORRECTION START_BYTE = 169 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = km OBJECT = ALIAS NAME = AR_DRAD USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The ephemeris_radius_correction element provides the value of the correction applied to the length of the alt_spacecraft_position_vector element by the post-fitting MGMORB phase of the altimetry and radiometry reduction program." END_OBJECT OBJECT = COLUMN NAME = EPHEMERIS_LONGITUDE_CORRECTION START_BYTE = 173 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = deg OBJECT = ALIAS NAME = AR_DLON USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The ephemeris_longitude_correction (VBF85) element provides the value of the correction applied to the footprint longitude value by the post-fitting MGMORB phase of the altimetry and radiometry reduction program." END_OBJECT OBJECT = COLUMN NAME = EPHEMERIS_LATITUDE_CORRECTION START_BYTE = 177 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = deg OBJECT = ALIAS NAME = AR_DLAT USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The ephemeris_latitude_correction (VBF85) element provides the value of the correction applied to the footprint latitude value by the post-fitting MGMORB phase of the altimetry and radiometry reduction program." END_OBJECT OBJECT = COLUMN NAME = ALT_PARTIALS_GROUP START_BYTE = 181 DATA_TYPE = VAX_REAL BYTES = 4 ITEMS = 18 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_PARTL USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The alt_partials_group of the alt_footprint_longitude, alt_footprint_latitude, and the derived_planetary_radius with respect to the alt_spacecraft_position_vector and alt_spacecraft_velocity_vector elements provides the value of the partial derivatives of the footprint coordinates with respect to changes in the spacecraft position and velocity." END_OBJECT OBJECT = COLUMN NAME = NON_RANGE_SHARP_FIT START_BYTE = 253 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_FIT USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The non_range_sharp_fit element provides the value of the 'goodness of fit' measuring the correlation between the observed profile non_range_sharp_echo_prof and the theoretical template best_non_range_sharp_model_tpt elements." END_OBJECT OBJECT = COLUMN NAME = SCALING_FACTOR START_BYTE = 257 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = 'km**2' OBJECT = ALIAS NAME = AR_SCALE USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The scaling_factor element provides the value of the conversion factor for the best_non_range_sharp_model_tpt and the non_range_sharp_echo_prof element that multiplies the integer array elements of the best_non_range_sharp_model_tpt and the non_range_sharp_echo_prof to yield their physical values, expressed as equivalent radar cross-sections in units of km**2." END_OBJECT OBJECT = COLUMN NAME = NON_RANGE_SHARP_LOOKS START_BYTE = 261 DATA_TYPE = LSB_UNSIGNED_INTEGER BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_LOOKS USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The non_range_sharp_looks element provides the value of the number of statistically independent measurements of echo profile that were summed to produce the value for the profile non_range_sharp_echo_prof element." END_OBJECT OBJECT = COLUMN NAME = NON_RANGE_PROF_CORRS_INDEX START_BYTE = 265 DATA_TYPE = LSB_UNSIGNED_INTEGER BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_NPROF0 USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The non_range_prof_corrs_index element provides the value of the index of the element in non_range_sharp_echo_prof that corresponds to the first element in best_non_range_sharp_model_tpt[0]. The indices start at zero." END_OBJECT OBJECT = COLUMN NAME = NON_RANGE_SHARP_ECHO_PROF START_BYTE = 269 DATA_TYPE = UNSIGNED_INTEGER BYTES = 1 ITEMS = 302 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_PROF USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The non_range_sharp_echo_prof element provides the value of the power vs. time echo profile, at half-baud (0.21 microsecond) intervals, assembled from up to 16 frequency components, without shifting their time origins (see range_sharp_echo_profile element). This profile yields the best estimate of the time dispersion of the echo, and hence the value of the radar_derived_surf_roughness and derived_fresnel_reflectivity element." END_OBJECT OBJECT = COLUMN NAME = BEST_NON_RANGE_SHARP_MODEL_TPT START_BYTE = 571 DATA_TYPE = UNSIGNED_INTEGER BYTES = 1 ITEMS = 50 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_TMPL USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The best_non_range_sharp_model_tpt provides the value of the theoretical echo profile, at half-baud (0.21 microsecond) intervals, that best approximates the peak of the non_range_sharp_echo_prof array. The optimal fit is made by matching best_non_range_sharp_model_tpt[i] with non_range_sharp_echo_prof[i+non_range_prof_corrs_index], where i is a value from 0 to 49." END_OBJECT OBJECT = COLUMN NAME = RANGE_SHARP_FIT START_BYTE = 621 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_RSFIT USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The range_sharp_fit element provides the value of the parameter which measures the correlation between the observed range_sharp_echo_profile and the theoretical template best_range_sharp_model_tmplt elements." END_OBJECT OBJECT = COLUMN NAME = RANGE_SHARP_SCALING_FACTOR START_BYTE = 625 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = 'km**2' OBJECT = ALIAS NAME = AR_RSSCALE USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The range_sharp_scaling_factor element provides the value of the conversion factor for the best_range_model_tmplt and the range_sharp_echo_profile element that multiplies the integer array of the best_range_model_tmplt and range_sharp_echo_profile elements to yield their physical values, expressed as specific radar cross-sections in units of km**2." END_OBJECT OBJECT = COLUMN NAME = RANGE_SHARP_LOOKS START_BYTE = 629 DATA_TYPE = LSB_UNSIGNED_INTEGER BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_RSLOOKS USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The range_sharp_looks element provides the value of the number of equivalent looks of statistically independent measurements of echo profile that were summed to produce the values for the range_sharp_echo_profile element." END_OBJECT OBJECT = COLUMN NAME = RANGE_SHARP_PROF_CORRS_INDEX START_BYTE = 633 DATA_TYPE = LSB_UNSIGNED_INTEGER BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_RSNPROF0 USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The range_sharp_prof_corrs_index element provides the value of the index of the element in range_sharp_echo_profile that corresponds to the first element in best_range_sharp_model_tmplt[0]. The indices start at zero." END_OBJECT OBJECT = COLUMN NAME = RANGE_SHARP_ECHO_PROFILE START_BYTE = 637 DATA_TYPE = UNSIGNED_INTEGER BYTES = 1 ITEMS = 302 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_RSPROF USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The range_sharp_echo_profile element provides the value of the power vs. time echo profile, at half-baud (0.21 microsecond) intervals, assembled from up to 16 frequency components, each shifted in time so as to align their rising edges. This profile yields the best estimate of the two-way echo time, and hence the value of the derived_planetary_radius element." END_OBJECT OBJECT = COLUMN NAME = BEST_RANGE_SHARP_MODEL_TMPLT START_BYTE = 939 DATA_TYPE = UNSIGNED_INTEGER BYTES = 1 ITEMS = 50 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_RSTMPL USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The best_range_sharp_model_tmplt element provides the value of the theoretical echo profile, at one-baud (0.21 microsecond) intervals, that best approximates the peak of the range_sharp_echo_profile array. The optimal fit is made by matching the best_range_sharp_model_tmplt[i] element with the range_sharp_echo_profile[i+range_sharp_prof_corrs_index] element, where i is a value from 0 to 49." END_OBJECT OBJECT = COLUMN NAME = MULT_PEAK_FRESNEL_REFLECT_CORR START_BYTE = 989 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_RHOFACT USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The mult_peak_fresnel_reflect_corr element provides the correction factor that has been applied to derived_fresnel_reflectivity to allow for radar echoes possessing more than an single peak." END_OBJECT OBJECT = COLUMN NAME = DERIVED_PLANETARY_THRESH_RADI START_BYTE = 993 DATA_TYPE = VAX_REAL BYTES = 4 UNIT = km OBJECT = ALIAS NAME = AR_RADIUS2 USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The derived_planetary_thresh_radi element provides the value of the threshold Venus radius for this radar footprint, obtained from the value of the derived_thresh_detector_index element, after correcting for atmospheric delay." END_OBJECT OBJECT = COLUMN NAME = SIGNAL_QUALITY_INDICATOR START_BYTE = 997 DATA_TYPE = IEEE_REAL BYTES = 4 UNIT = dB OBJECT = ALIAS NAME = AR_SQI USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The signal_quality_indicator element provides a measure of the signal-to- noise-ratio of the measurement of the derived_thresh_detector_index value. It is the ratio between the sum of the 10 successive values of range_sharp_echo_profile, starting 10 values after the element numbered by the derived_thresh_detector_index element value, to the 10 successive values of range_sharp_echo_profile, starting 20 values before the element numbered by the derived_thresh_detector_index element value. This ratio is expressed in decibels." END_OBJECT OBJECT = COLUMN NAME = DERIVED_THRESH_DETECTOR_INDEX START_BYTE = 1001 DATA_TYPE = LSB_UNSIGNED_INTEGER BYTES = 4 UNIT = 'N/A' OBJECT = ALIAS NAME = AR_THRESH USAGE_NOTE = "MAGELLAN MIT ARCDR SIS" END_OBJECT DESCRIPTION = " The derived_thresh_detector_index element provides the value of the element in range_sharp_echo_profile that satisfies the altimeter threshold detection algorithm, representing the distance to the nearest object in this radar footprint in units of 33.2 meters, modulus a 10.02 kilometer altimeter range ambiguity." END_OBJECT