Data Set Information
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| DATA_SET_NAME |
C130 EARTH ASAS CALIBRATED REDUCED DATA RECORD IMAGE V1.0
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| DATA_SET_ID |
C130-E-ASAS-3-RDR-IMAGE-V1.0
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| NSSDC_DATA_SET_ID |
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| DATA_SET_TERSE_DESCRIPTION |
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| DATA_SET_DESCRIPTION |
Data Set Overview : Most of the ASAS data acquired for GRSFE were taken during flights over Lunar Lake, Nevada, at a nominal altitude of 5000 m above ground level. Flights over Lunar Lake were repeated to acquire data for a range of solar zenith angles and to obtain data for several view azimuth angles (i.e., for several flight headings relative to the solar principal plane). On most flights, the sensor field of view was initially pointed forward 45 degrees as the aircraft approached the site. The sensor then imaged the site through a sequence of seven fore-to-aft view directions ranging from 45 degrees forward to 45 degrees aft in 15 degree increments as the aircraft flew over the site. The primary target of interest was the Lunar Lake playa, but the digital images also include data for the lava flow and cobble areas within and around the playa. Data were acquired in a similar manner on one flight over the Ubehebe Crater. One flight over Lunar Lake was also flown approximately along the solar principal plane with the ASAS view zenith angle fixed at the solar zenith angle. The purpose of this flight was to observe the opposition effect. Several characteristics of the ASAS digital image data should be noted by investigators and analysts. First, the image data are geometrically distorted. One reason for the distortion is the roll, pitch, and yaw of the C-130 aircraft during data acquisition. A second reason is the rectangular, instead of square, dimensions of the surface area represented by each image pixel. The pixel dimensions depend on the aircraft speed, the instrument scan rate, and the pointing angle of the instrument. Two of the ASAS scenes (with GRSFE product IDs ASALL04D and ASALL05D) were acquired at 48 scan lines per sec. Given the nominal aircraft speed of 100 meters per second, the along-track pixel dimension in these two scenes is 2 meters. The rest of the ASAS scenes were acquired at a scan rate of 64 scan lines per second and the along-track pixel dimension for these scenes is 1.5 meters. The across-track dimensions of the pixels in all of the ASAS scenes are 4.3 meters, 4.5 meters, 5.0 meters, and 6.1 meters for pointing angles of 0 (nadir), 15, 30, and 45 degrees, respectively. No attempt has been made to geometrically rectify the ASAS digital image data provided for the GRSFE CD-ROMs. Another intermittent distortion has been observed during initial inspections of ASAS imagery acquired for GRSFE. The scan lines occasionally appear to shift laterally by one or two pixels with the direction of the shift alternating every scan line. This distortion is most clearly exhibited at a smooth boundary between a bright area and a dark area within a scene. Such smooth boundaries will occasionally appear jagged in ASAS imagery particularly when the image around the boundary is magnified. The cause of this distortion has not yet been determined. Investigators and analysts should also note that the ASAS data are stored as binary integers in units of 0.1 watts/(meter squared * micrometer * steradian). In other words, any integer ASAS datum should be divided by 10 to recover a real number radiance value in units of watts/(meter squared * micrometer * steradian). The factor of 10 for all ASAS channels was chosen for the convenience of analysts. Analysts should not infer that the radiometric resolution of each ASAS detector is 0.1 watts/(meter squared * micrometer * steradian) per raw digital count. The actual radiometric resolution varies from channel to channel and, to a lesser degree, from detector to detector for the 512 detectors per channel. Processing Level Id : 3 Software Flag : N Processing Start Time : 1989-07-23T00:00:00.000 Processing Stop Time : 1990-02-27T00:00:00.000 Parameters : Data Set Parameter 'RADIANCE' ----------------------------- Radiance is the amount of energy per time per projected area per steradian. Data Set Parameter Name : RADIANCE Data Set Parameter Unit : WATT/(METER*METER)/STERADIAN Sampling Parameter Name : PIXEL Sampling Parameter Unit : METER Minimum Sampling Parameter : N/A Maximum Sampling Parameter : N/A Sampling Parameter Resolution : 12.02 Sampling Parameter Interval : 4.25 Minimum Available Sampling Int : N/A Noise Level : UNK Source Instrument Parameters : Instrument Host ID : C130 Data Set Parameter Name : RADIANCE Instrument Parameter Name : RADIANCE Important Instrument Parameters : 1 Measurement Information : Atmospheric Conditions ---------------------- Not Applicable Source ------ The sunlight reflected from the Earth's surface is the source of the measurement. Calibration Standard -------------------- Not Applicable Wavelength Calibration ---------------------- Not Applicable Processing : Processing History ------------------ Source Data Set ID : N/A Software : UNK Product Data Set ID : C130-E-ASAS-3-RDR-IMAGE-V1.0
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| DATA_SET_RELEASE_DATE |
1991-05-28T00:00:00.000Z
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| START_TIME |
1989-07-17T02:33:05.000Z
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| STOP_TIME |
1989-07-17T09:16:42.000Z
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| MISSION_NAME |
GEOLOGIC REMOTE SENSING FIELD EXPERIMENT
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| MISSION_START_DATE |
1989-07-01T12:00:00.000Z
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| MISSION_STOP_DATE |
1989-10-31T12:00:00.000Z
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| TARGET_NAME |
EARTH
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| TARGET_TYPE |
PLANET
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| INSTRUMENT_HOST_ID |
C130
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| INSTRUMENT_NAME |
ADV. SOLID-STATE ARRAY SPECTRORADIOMETER
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| INSTRUMENT_ID |
ASAS
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| INSTRUMENT_TYPE |
IMAGING SPECTROMETER
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| NODE_NAME |
Geosciences
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| ARCHIVE_STATUS |
ARCHIVED
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| CONFIDENCE_LEVEL_NOTE |
Overview : The digitized response of each detector element to incident radiant flux is characterized as a piecewise linear function of spectral radiance on the basis of the laboratory calibration data. The data acquired by each detector in flight are converted to radiance units by inverting the appropriate response function. The resulting values are stored as binary integers in units of 0.1 W/(m**2 sr). The uncertainty associated with spectral radiance values is approximately 6%. Note that the values represent the radiant flux received by the sensor at the altitude of the platform aircraft. The calibration and correction procedures are discussed in greater detail by Irons and Irish, 1988 and Irons, et al., 1989. Finally, band 1 was inoperable, but data for this band are included in the ASAS data set.
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| CITATION_DESCRIPTION |
Irons, J. R., C130 EARTH ASAS CALIBRATED REDUCED DATA RECORD IMAGE V1.0, C130-E-ASAS-3-RDR-IMAGE-V1.0, NASA Planetary Data System, 1991
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| ABSTRACT_TEXT |
Most of the ASAS data acquired for GRSFE were taken during flights over Lunar Lake, Nevada, at a nominal altitude of 5000 m above ground level. Flights over Lunar Lake were repeated to acquire data for a range of solar zenith angles and to obtain data for several view azimuth angles (i.e., for several flight headings relative to the solar principal plane). On most flights, the sensor field of view was initially pointed forward 45 degrees as the aircraft approached the site. The sensor then imaged the site through a sequence of seven fore-to-aft view directions ranging from 45 degrees forward to 45 degrees aft in 15 degree increments as the aircraft flew over the site. The primary target of interest was the Lunar Lake playa, but the digital images also include data for the lava flow and cobble areas within and around the playa. Data were acquired in a similar manner on one flight over the Ubehebe Crater. One flight over Lunar Lake was also flown approximately along the solar principal plane with the ASAS view zenith angle fixed at the solar zenith angle. The purpose of this flight was to observe the opposition effect.
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| PRODUCER_FULL_NAME |
JAMES R. IRONS
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| SEARCH/ACCESS DATA |
Geosciences Web Services
Geosciences FTP Resource
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