Data Set Overview : PARABOLA data were obtained at three GRSFE modeling sites in the Lunar Crater Volcanic Field. The playa site, the cobble site, and the mantled flow site. Each site was imaged by PARABOLA at a variety of solar incidence angles to characterize the scattering properties of the surface completely. This information can be used as a reference to correct airborne data from ASAS and AVIRIS from any lighting and viewing geometry, or as a base data set to test radiative transfer models. Six sets of data from the playa site were gathered primarily on July 17, 1989 with solar incidence angles that varied from 28 to 71 degrees. Five sets of cobble site data were gathered during the morning of July 18, 1989 with incidence angles from 19 to 57 degrees. Data from the mantled flow site was obtained six times during the afternoon of July 18 with incidence angles from 21 to 73 degrees. In all, over 1000 data points exist for each site to characterize its scattering properties. Additionally, an equal number of points exist for the sky above the sites.  The data are presented in two formats. The first set of files contain the complete, though filtered, data set consisting of almost all the individual pixels from the three replicate scans of the same site. Because of the scanning pattern of PARABOLA, the pixels are not at equidistant angles in the off-nadir or azimuth viewing planes. For users who prefer average sets of data binned into even intervals, the second set of files were created. In these files, the raw data of the first set of files has been averaged into bins with centers every 15 degrees in off-nadir and 30 degrees in azimuth.  Throughout the days during which PARABOLA data were being gathered, a white barium sulfate reference plate was periodically measured by PARABOLA. This plate is known to be Lambertian within a correctable amount. The measured radiance of this plate was plotted as a function of the time of day (or solar zenith angle) and fit to a sinusoid. In this way, the radiance from a Lambertian reference is known at any time during the data gathering period.  Processing Level Id : 3 Software Flag : N Processing Start Time : 1989-07-20T00:00:00.000 Processing Stop Time : 1991-05-28T00:00:00.000   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 : WAVELENGTH Sampling Parameter Unit : MICROMETER Minimum Sampling Parameter : 0.65 Maximum Sampling Parameter : 1.69 Sampling Parameter Resolution : 0.2 Sampling Parameter Interval : N/A Minimum Available Sampling Int : N/A Noise Level : UNK   Source Instrument Parameters : Instrument Host ID : FEXP Data Set Parameter Name : RADIANCE Instrument Parameter Name : RADIANCE Important Instrument Parameters : 1   Measurement Information :  Atmospheric Conditions ---------------------- Not Applicable   Source ------ The source is sunlight or reflected sunlight.   Calibration Standard -------------------- Not Applicable   Wavelength Calibration ---------------------- Not Applicable   Processing :  Processing History ------------------ Source Data Set ID : N/A Software : UNK Product Data Set ID : FEXP-E-PARB-3-RDR-SPECTRUM-V1.0

Overview : In averaged data files, the last column gives the number of points used to compute the average of the bin. If there are gaps due to instrument shadows, instrument noise, or other causes, the value of the bin is taken from its mirror bin (this assumes symmetry of data across the solar principal plane). To identify these cases, the number of data points averaged is assigned a negative (mirror image) value. If for some reason, there is no data for substitution, an interpolated value is used. Since interpolated values are not real data, the user is cautioned by placing a zero in the last column.