DATA_SET_DESCRIPTION |
Data Set Overview
=================
This data set contains 52-color IR spectra taken using a double
circularly variable filter. The short wavelength portion of the CVF
covered the octave from 0.8 to 1.6 microns with 3 percent resolution,
while the long wavelength portion covered 1.5 to 2.6 microns with 5
percent resolution. There is some overlap in the spectral coverage
between 1.5 and 1.6 microns, which is evident as a discontinuity in the
wavelengths after the first 32 values, which were obtained with the short
wavelength portion, while the remaining 20 values were obtained with the
long wavelength portion.
Errors were computed from the standard deviation of the multiple scans
through the CVF. If only one scan was performed, the error is left
blank. Note that due to the small number of scans, the errors are often
both underestimated and overestimated.
Some wavelength positions correspond to telluric features and were
intentionally blanked. In other cases, especially near the ends of the
CVF, the data were either not taken or were hopelessly noisy, so those
entries were also blanked.
The following code letters are used for the various solar analog stars:
A = 18 Aquarii
B = 16 Cygni B
O = 13 Orionis
V = 70 Virginis
The observation date for 113 Amalthea is given as 054/05/85 in the
original machine readable data file. The assumption has been made that
the 4 is a typographical error, based on the fact that other observations
were made on 05/05/85.
Not all dates of observation are available. In particular, those
asteroid observations contributed by R.H. Brown did not include
observation dates in the original machine readable data file.
One observation was taken from the literature, namely Cruikshank and
Hartmann (1984) [CRUIKSHANK&HARTM1984].
Reference: Cruikshank, D.P., and W.K. Hartmann 1984. The meteorite-
asteroid connection: Two olivine-rich asteroids. Science 223, 281-283.
[CRUIKSHANK&HARTM1984]
Parameters
==========
The data tables have one entry for each observation, with fields for the
following parameters: asteroid catalog number; a code for the solar
analog star used with that observation; the date of observation; and
reflectances and error values for each of 52 bandpasses.
Data
====
The reflectances in each of the 52 bands are given in the table
52color.tab'. The errors are given in the table '52error.tab'. The
asteroid identification, solar analog code, and observation date are
provided in each of these two files.
Ancillary Data
==============
The ancillary file '52waves.tab' presents the effective wavelengths of
each of the 52 positions of the CVF which were used for the survey,
arranged in a single record with a separate field for each wavelength.
The file '52waves2.tab' gives the same information arranged with one
wavelength per record. Each record also contains the FWHM of the
bandpass.
Modification History
====================
As part of a general review of asteroid holdings in February 2002, these
data were examined and the existing labels edited slightly. In addition,
a new format for the spectra was also provided. No data values were
changed, nor were the formats of the existing data files altered.
In January 2005, the data set was again updated to comply with current
standards, including the addition of a citation description.
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CITATION_DESCRIPTION |
Bell, J. F., Owensby, P.D., Hawke, B.R., Brown, R.H., Cruikshank,
D., and Hartmann, W.K., 52-color Asteroid Survey.
EAR-A-RDR-3-52COLOR-V2.1. NASA Planetary Data System, 1995.
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