PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 2880 /* FITS standard record length */ FILE_RECORDS = 8 FILE_NAME = "RA_WAVE_006.LBL" DATA_FORMAT = FITS /* INSTRUMENT AND MISSION DESCRIPTIVE DATA ELEMENTS */ INSTRUMENT_ID = "ALICE" INSTRUMENT_NAME = "ALICE" INSTRUMENT_TYPE = "ULTRAVIOLET SPECTROMETER" INSTRUMENT_HOST_ID = "RO" INSTRUMENT_HOST_NAME = "ROSETTA-ORBITER" MISSION_ID = "ROSETTA" MISSION_NAME = "INTERNATIONAL ROSETTA MISSION" /* DATA OBJECT POINTERS IDENTIFICATION DATA ELEMENTS */ ^PRIMARY_HEADER = ("RA_WAVE_006.FIT",1) ^WAVELENGTH_SOLUTION_TABLE = ("RA_WAVE_006.FIT",3) ^QUADRATIC_SOLUTION_HEADER = ("RA_WAVE_006.FIT",4) ^QUADRATIC_SOLUTION_TABLE = ("RA_WAVE_006.FIT",5) ^LINEAR_SOLUTION_HEADER = ("RA_WAVE_006.FIT",6) ^LINEAR_SOLUTION_TABLE = ("RA_WAVE_006.FIT",7) ^ROW_OFFSET_HEADER = ("RA_WAVE_006.FIT",8) ^ROW_OFFSET_TABLE = ("RA_WAVE_006.FIT",9) /* PRODUCT, DATA SET, AND VOLUME DATA ELEMENTS */ PRODUCT_ID = "RA_WAVE_006" PRODUCT_CREATION_TIME = 2010-03-29T10:01:00 DATA_SET_ID = "RO-C/CAL-ALICE-4-ESC1-V1.0" PRODUCER_ID = "ROSETTA_ALICE" PRODUCER_FULL_NAME = "ANDREW J. STEFFL" PRODUCER_INSTITUTION_NAME = "SOUTHWEST RESEARCH INSTITUTE" /* DATA OBJECT DEFINITIONS */ OBJECT = PRIMARY_HEADER BYTES = 2880 /* RECORD_BYTES x RECORDS */ HEADER_TYPE = FITS INTERCHANGE_FORMAT = ASCII RECORDS = 1 DESCRIPTION = " FITS (Flexible Image Transport System) format is defined in 'Astronomy and Astrophysics', volume 376, page 359; bibcode 2001A&A...376..359H This file contains the wavelength solution for the Alice UV Spectrograph on the Rosetta spacecraft. The wavelength solution is derived a 20th order polynomial fit to the locations of known spectral features in observations of the Earth, Luna, Mars, C/2002 LINEAR T7, and several UV-bright stars. To keep the high order fit from blowing up at the edges, artificial data points were added at columns 90, 120, 150, 860, 890, and 920. Columns 0-89 and 917-1023 use a 2nd order fit to the data to prevent the wavelength solution from rolling over or going negative. Note that the actual wavelength range covered by the Alice UV spectrometer is 700-2050 Angstroms. When a charge pulse strikes the readout anodes, the detector electronics assigns it a 10-bit X value and a 5-bit Y-value. The mapping of physical space on the detector to data space does not use the full 10-bit X range. Instead, events on the detector are mapped into columns 130-900 (approximately) in data space. The regions in data space on either side of this range do not have any physical meaning, and are conceptually similar to overscan areas found in CCD data." END_OBJECT = PRIMARY_HEADER OBJECT = WAVELENGTH_SOLUTION_TABLE INTERCHANGE_FORMAT = BINARY ROWS = 21 COLUMNS = 1 ROW_BYTES = 8 DESCRIPTION = " Polynomial coefficients for the 20th order fit to the R-Alice wavelength scale as a function of detector column number." OBJECT = COLUMN NAME = "20TH ORDER POLYNOMIAL WAVELENGTH SOLUTION" DATA_TYPE = IEEE_REAL /* 64-bit floating point */ BYTES = 8 START_BYTE = 1 END_OBJECT = COLUMN END_OBJECT = WAVELENGTH_SOLUTION_TABLE OBJECT = QUADRATIC_SOLUTION_HEADER BYTES = 2880 /* RECORD_BYTES x RECORDS */ HEADER_TYPE = FITS INTERCHANGE_FORMAT = ASCII RECORDS = 1 DESCRIPTION = " Polynomial coefiencients for the quadratic fit to the R-Alice wavelength solution used for columns 0-89 and 917-1023." END_OBJECT = QUADRATIC_SOLUTION_HEADER OBJECT = QUADRATIC_SOLUTION_TABLE INTERCHANGE_FORMAT = BINARY ROWS = 3 COLUMNS = 1 ROW_BYTES = 8 DESCRIPTION = " This extension contains polynomial coefficents used for columns 0-89 and 917-1023 of the wavelength solution. This is outside the active area of the detector, and therefore beyond the actual wavelength range of the data. This low-order fit is used at the ends of the wavelength solution to avoid the wavelength solution going negative or rolling over and for better results with auto-scaled plots." OBJECT = COLUMN NAME = "QUADRATIC WAVELENGTH SOLUTION" DATA_TYPE = IEEE_REAL /* 64-bit floating point */ BYTES = 8 START_BYTE = 1 END_OBJECT = COLUMN END_OBJECT = QUADRATIC_SOLUTION_TABLE OBJECT = LINEAR_SOLUTION_HEADER BYTES = 2880 /* RECORD_BYTES x RECORDS */ HEADER_TYPE = FITS INTERCHANGE_FORMAT = ASCII RECORDS = 1 DESCRIPTION = " Polynomial coefiencients for the linear fit to the R-Alice wavelength solution used for columns 0-89 and 917-1023." END_OBJECT = LINEAR_SOLUTION_HEADER OBJECT = LINEAR_SOLUTION_TABLE INTERCHANGE_FORMAT = BINARY ROWS = 2 COLUMNS = 1 ROW_BYTES = 8 DESCRIPTION = " This extension contains the parameters for the best-fit linear wavelength solution for R-Alice. It is used in the linearized data product" OBJECT = COLUMN NAME = "LINEAR WAVELENGTH SOLUTION" DATA_TYPE = IEEE_REAL /* 64-bit floating point */ BYTES = 8 START_BYTE = 1 END_OBJECT = COLUMN END_OBJECT = LINEAR_SOLUTION_TABLE OBJECT = ROW_OFFSET_HEADER BYTES = 2880 /* RECORD_BYTES x RECORDS */ HEADER_TYPE = FITS INTERCHANGE_FORMAT = ASCII RECORDS = 1 DESCRIPTION = " FITS Header for the row offset extension." END_OBJECT = ROW_OFFSET_HEADER OBJECT = ROW_OFFSET_TABLE INTERCHANGE_FORMAT = BINARY ROWS = 32 COLUMNS = 1 ROW_BYTES = 4 DESCRIPTION = " Optical distortion in the instrument (primarily coma) causes the image of the entrance slit on the detector to appear somewhat curved. This extension contains the offset (in pixels) of the centroid of a spectral feature in a particular row from it's location in row 15, the center of the detector. The offset is applied in the following manner: lambda(X, Y) = lambda(X + offset(y), 15)" OBJECT = COLUMN NAME = "ROW OFFSET" DATA_TYPE = IEEE_REAL /* 32-bit floating point */ BYTES = 4 START_BYTE = 1 END_OBJECT = COLUMN END_OBJECT = ROW_OFFSET_TABLE END