This program will read a binary SELENE Kaguya SP (Spectral Profiler) data file
(downloaded as a .spc file from the archive site) and create a
user-specified, tab-delimited text file.
The multi-column ASCII text file will contain one record for each of the 296 wavelengths (bands or channels) in the SP file.
The bands are derived from 3 separate sensors, with wavelengths as follows: UVVIS wavelength = 512.6 -1010.7 nm; NIR1
wavelength = 883.5 - 1676.0 nm; NIR2 wavelength = 702.1-2587.9 nm. Each record in the output file will contain ancillary data
and all of the observations for a specific wavelength. You can limit the number of observations that
are listed by using the MINOBS and MAXOBS parameters. The ancillary data include a quality assessment (QA) parameter,
raw DN, radiance, and ref_1 and ref_2 (reflectance values that have been photometrically corrected using values for
highlands and mare, respectively) for each wavelength and each observation. SP binary data files can have less than 10 observations
or more than 50. This program works on both Level 2B and Level 2C products from Kaguya, with two caveats:
the NIR portions of the Level 2B products are not calibrated or photometrically corrected, but the L2C products have been fully
calibrated and photometrically corrected.
The documents in the kaguyasp2ascii/assets directory provide information about the Kaguya Spectral
Profiler data. The directory also contains a summary of what the different Quality Assessment values
mean (from p. 82 of the LISM SPICE documentation).
Note that this program does not process the SP data in any way once the binary data is converted to ASCII.
For example, you likely would not want to work with SP data that have oblique viewing angles or are poorly illuminated
(these must be filtered from the archive site), or you may want to remove redundant or erroneous data at the instrument joins
(e.g., spikes in DN values at the ends of the VIS, NIR1, NIR2). For the latter, the QA values will help you to identify these.
QA values with any of the three left-most bits set to 1 can be removed from each spectrum.
References:
Yamamoto, S. et al. (2011) Preflight and in-flight calibration of the spectral profiler onboard the SELENE (Kaguya). IEEE Trans. Geosci. Remote Sens. 49 (11), p. 4660-4676.
Yamamoto, S. et al. (2014) Calibration of NIR2 of Spectral Profiler onboard Kaguya/SELENE, IEEE Trans. Geosci. Remote Sens. 52 (11), p. 6882-6898.
Yokota, Y., et al. (2011) Lunar photometric properties at wavelengths 0.5-1.6mm acquired by SELENE Spectral Profiler and their dependency on local albedo and latitudinal zones. Icarus, 215, 639-660, http://dx.doi.org/10.1016/j.icarus.2011.07.028.
