Data Set Information
DATA_SET_NAME GSSR V RTLS 5 12.6-12.9CM RADAR SCALED ECHO POWER/ALT V1.0
DATA_SET_ID GSSR-V-RTLS-5-12.6-9CM-V1.0
NSSDC_DATA_SET_ID
DATA_SET_TERSE_DESCRIPTION
DATA_SET_DESCRIPTION Data Set Overview : The Goldstone Solar System Radar observations of Venus from 1972 until 1988 are included in this data set. The system operated at 12.6 cm up until 1977; afterward the system operated at 12.9 cm. The data consist of radar scaled backscatter cross sections in image format and, in most cases, associated altimetry observations. The data were acquired over 52 separate observing runs. In total the observations cover the region between approximately 260 degrees (leftmost) east longitude to 30 degrees (rightmost) east longitude, within approximately 20 degrees of the equator. Backscatter data were acquired with opposite sense circular polarization with incidence angles typically less than 10 degrees. Associated altimetric data were acquired using a two or three station interferometric system. Data are presented in Mercator projection with degrees/pixel in longitude dependent on the individual data file. Processing Level Id : 5 Software Flag : N Processing Start Time : 1972-06-01 Processing Stop Time : 1990-04-01 Parameters : Data Set Parameter 'RADAR SCALED BACKSCATTER CROSS SECTION' ----------------------------------------------------------- Cross section values that are scaled by some procedure, such as dividing by theoretical or empirical scattering laws. Data Set Parameter Name : RADAR SCALED BACKSCATTER CROSS SECTION Data Set Parameter Unit : DIMENSIONLESS Sampling Parameter Name : PIXEL Sampling Parameter Unit : N/A Minimum Sampling Parameter : N/A Maximum Sampling Parameter : N/A Sampling Parameter Resolution : N/A Sampling Parameter Interval : N/A Minimum Available Sampling Int : N/A Noise Level : UNK Source Instrument Parameters : Instrument Host ID : GSSR Data Set Parameter Name : RADAR SCALED BACKSCATTER CROSS SECTION Instrument Parameter Name : RADAR ECHO POWER Important Instrument Parameters : 1 Measurement Information : Atmospheric Conditions ---------------------- NOT APPLICABLE Source ------ The transmitter was the 64 meter antenna at the Goldstone Deep Space Network station. Calibration Standard -------------------- NOT APPLICABLE Wavelength Calibration ---------------------- The transmitter frequency is calibrated with a hydrogen maser. Processing : N/A
DATA_SET_RELEASE_DATE 1990-06-15T00:00:00.000Z
START_TIME 1972-06-20T12:00:00.000Z
STOP_TIME 1988-07-27T12:00:00.000Z
MISSION_NAME PRE-MAGELLAN
MISSION_START_DATE 1968-11-09T12:00:00.000Z
MISSION_STOP_DATE 1988-07-27T12:00:00.000Z
TARGET_NAME VENUS
TARGET_TYPE PLANET
INSTRUMENT_HOST_ID GSSR
INSTRUMENT_NAME RADIO TELESCOPE
INSTRUMENT_ID RTLS
INSTRUMENT_TYPE RADAR
NODE_NAME Geosciences
ARCHIVE_STATUS ARCHIVED
CONFIDENCE_LEVEL_NOTE Overview : Pre-1977 backscatter images are normalized relative to the square root of the scattering properties for an annulus about the sub-Earth point including the data. The 1977 and later images are normalized relative to the average scattering properties for the annulus. Most of the backscatter images are speckle noise limited as opposed to thermal noise. The confidence is usually limited by the number of looks. The errors in the altimetry data are difficult to estimate and vary greatly over the image. These errors depend upon the accuracy of the ephemeris, the variation of the interferometer fringe spacings, the signal to noise ratio and therefore the scattering law appropriate for each day's observation. The maximum likelihood estimator also does not provide an estimate of the errors. Errors range from 30 meters near the sub-radar region to a few kilometers at the outer edge of the image.
CITATION_DESCRIPTION Jurgens, R. F., GSSR V RTLS 5 12.6-12.9CM RADAR SCALED ECHO POWER/ALT V1.0, GSSR-V-RTLS-5-12.6-9CM-V1.0, NASA Planetary Data System, 1990
ABSTRACT_TEXT The Goldstone Solar System Radar observations of Venus from 1972 until 1988 are included in this data set. The system operated at 12.6 cm up until 1977 operated at 12.9 cm. The data consist of radar scaled backscatter cross sections in image format and, in most cases, associated altimetry observations. The data were acquired over 52 separate observing runs. In total the observations cover the region between approximately 260 degrees (leftmost) east longitude to 30 degrees (rightmost) east longitude, within approximately 20 degrees of the equator. Backscatter data were acquired with opposite sense circular polarization with incidence angles typically less than 10 degrees. Associated altimetric data were acquired using a two or three station interferometric system. Data are presented in Mercator projection with degrees/pixel in longitude dependent on the individual data file.
PRODUCER_FULL_NAME RAYMOND F. JURGENS
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