|
These data sets are used as input to the standard calibration program, CALHRS, which produces a new set of calibrated data files:
All files for a particular observation have the same
root file name;
the type of data in each file is identified by its extension.
The format of all retrieved files from the ST-ECF archive is FITS.
File Name Suffixes [Short Description]
Suffix |
File Contents |
Suffix |
File Contents |
|---|---|---|---|
|
.d0
|
Raw science data
|
.c0
|
Calibrated wavelength solution
|
|
.q0
|
Data quality for raw science image
|
.c1
|
Calibrated science data (fluxes)
|
|
.d1
|
Return-to-Brightest & SSA ACQ/PEAKUP
|
.c2
|
Propagated statistical error
|
|
.q1
|
Data quality for RTB & SSA ACQ/PEAKUP
|
.c3
|
Calibrated special diodes
|
|
.x0
|
Extracted engineering data
|
.c4
|
Special diodes data quality
|
|
.xq
|
Data quality for extracted engineering data
|
.c5
|
Background
|
|
.sh
|
Standard Header Packet
|
.cq
|
Calibrated science data quality
|
|
.ul
|
Unique Data Log
|
.jit, .jif
|
Jitter files (post- and pre-COSTAR)
|
|
.trl
|
Trailer file
|
.pdq or .ocx
|
PODPS data quality files
|
More detailed description:
| File Type | Short Name | File Extension | Short Description |
|---|---|---|---|
| Standard Header Packet | SH | shf.fits | Telemetry values for GHRS-specific software monitors and the current value table which includes calibration-critical engineering data (such as temperatures at various points in the instrument), spacecraft operation data (such as target position and spacecraft orbit) |
| Unique Data Log | UL | ulf.fits | It contains the command values (i.e., the observation control table) for the current observation as well as some observation data produced by the flight software. These observation values include X/Y deflection offset for the spectral calibration lamps, spectrum Y-balance offset, null deflection calibration correction, target coordinates prior centering, flux measurement at end of target acquisition, and proportional deflection calibration corrections. |
| Science Data file (or Target Acquisition) | D0 | d0f.fits | It contains single-precision floating-point values for the 500 science diodes. In accumulation mode these values contain unscrambled, co-added, and comb-added diode data. In rapid-readout mode the data comprise unscrambled raw counts from the detector diodes. The header includes UDL values for X/Y deflections, horizontal/vertical deflections, repeat codes, and bin identifications for substep patterns, as well as temperature, current and voltage SHP telemetry values. |
| Return-To-Brightest and Small Science Aperture ACQ/PEAKUP | D1 | d1f.fits | Most acquisitions of point sources since mid-1993 used the return-to-brightest algorithm, in which the aperture (LSA or SSA) was rastered in a 3 x 3 or 5 x 5 pattern, and the pointing with the most counts was returned to for peakup and observation. The return-to-brightest (RTB) target acquisition record is in the .d1h image and also in the trailer file (.trl). This image contains the total counts at each dwell point in the spiral search performed by the RTB acquisition algorithm. SSA ACQ/PEAKUPs use the same algorithm as RTB target acquisitions. Therefore they will also have a .d1h file whose header file contains information on which dwell point (MAPFND) contained the largest flux (FLUXFND). The data quality image (.q1h) associated with the RTB data records whether there is fill data due to technical problems with the observation or due to problems in transmitting the data from the telescope. |
| Extracted Data file | X0 | x0f.fits | In the accumulation and in the rapid-readout mode, the extracted data are the single-precision floating-point values for the twelve special diodes, i.e., the focus diodes, background monitor diodes, and the radiation background monitor diodes, plus engineering trailer and flight software information. |
| Science (or Target Acquisition) Data Quality file | Q0 | q0f.fits | It contains flags or fill values for bad data in the corresponding data file. Good data values are identified with a zero. If because of data-dropouts the data has been filled, the data quality value is 16. If the datum failed the Reed-Solomon error check, the data quality value is 1. |
| Extracted Data Quality file | XQ | xqf.fits | |
| Calibrated Wavelength file | C0 | c0.fits | It contains the single-precision floating-point calibrated wavelengths for the science diodes. |
| Calibrated Flux file | C1 | c1.fits | It contains the single-precision floating-point calibrated fluxes for the science diodes. |
| Propagated Statistical Error file | C2 | c2.fits | It contains a measure of the statistical errors of the original data values; this file is calibrated in lock-step with the Science Data file. |
| Output Data Quality file | CQ | cq.fits | It flags bad pixels values in the Calibrated Wavelength, Flux, and Propagated Statistical Error files. |
| Calibrated Special Diodes file | C3 | c3.fits | It is a copy of the Extracted Data file that contains the calibrated values of the special diodes; this is used for such purposes as background removal. The special diodes do not have photocathode granularity removed, background subtracted, echelle ripple removed nor are they converted to absolute flux units. |
| Special Diodes Data Quality files | C4 | c4.fits | It flags bad pixels values in the Calibrated Special Diodes file |