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Primary Header

The primary header contains all required GBT FITS keywords, for example:

SIMPLE  =                    T / file does conform to FITS standard
BITPIX  =                    8 / number of bits per data pixel
NAXIS   =                    0 / number of data axes
EXTEND  =                    T / FITS dataset may contain extensions
COMMENT   FITS (Flexible Image Transport System) format is defined in 'Astronomy
COMMENT   and Astrophysics', volume 376, page 359; bibcode: 2001A\&A...376..359H
ORIGIN  = 'NRAO Green Bank'    /
INSTRUME= 'CCB'                / device or program of origin
GBTMCVER= '4.6     '           / telescope control software release
FITSVER = '1.2     '           / FITS definition version for this device
DATEBLD = 'Mon Sep 20 20:58:25 UTC 2004' / time program was linked
SIMULATE=                    0 / Is the instrument in simulate mode?
DATE-OBS= '2004-10-09T07:50:01' / Manager parameter startTime
TIMESYS = 'UTC     '           / time scale specification for DATE-OBS
TELESCOP= 'NRAO_GBT'           / Green Bank Telescope (Robert C. Byrd 100m)
OBJECT  = '2230+114'           / Manager parameter source
PROJID  = 'AGBT04C_018_04'     / Manager parameter projectId
OBSID   = 'lineFSW '           / Manager parameter scanId
SCAN    =                  305 / Manager parameter scanNumber
END

In addition to the above standard keyword/value pairs, the following intrument-specific keyword/value pairs are recorded:


Keyword Values Related CCB Library Call Units
ACTPSW A,B,Both,None ccb_set_phase_switch_cnf.active_switches  
  NOTES: Designate active phase switches
INPSWSTA 0,1 ".closed_switches  
  NOTES:Important if one switch is held constant so you know what it was
INPSWSTB 0,1 ".closed_switches  
  NOTES:Important if one switch is held constant so you know what it was
SMPPERST integer ".samp_per_state 100 ns
  NOTES: number of ADC samples per phase switch state
CALCYCLN integer ccb_set_cal_diode_cnf.ncal  
  NOTES: number of integrations in the calibration cycle
CALOFFIG integer ".diode_times  
  NOTES:duration of the cal off step, integrations
LCALONIG integer ".diode_times  
  NOTES:duration of the left cal on step, integrations
BCALONIG integer ".diode_times  
  NOTES:duration of the both cal on step, integrations
RCALONIG integer ".diode_times  
  NOTES:duration of the right cal on step, integrations
INTGPD integer ccb_set_timing_cnf.integ_period  
  NOTES: number of phase switch cycles which go into one integration
PSWDT integer ccb_set_timing_cnf.phase_switch_dt 100 ns
  NOTES:phase switch transition blanking interval
CRISEDT integer ".diode_rise_dt 100 ns
  NOTES:Cal diode settling time after being switched on (determines # blanked integs)
CFALLDT integer ".diode_fall_dt 100 ns
  NOTES:Cal diode settling time after being switched off determines # blanked integs)
RNDTRPDT integer ".roundtrip_dt 100 ns
  NOTES:Internal hardware round trip delay
HOLDOFF integer ".holdoff_dt 100 ns
  NOTES:minimum interval between hardware interrupts
INTEGRAT integer ccb_integration_time() 100 ns
  NOTES: integration time per phase after blanking
FAKESMP logical    
  NOTES: T indicates that data were generated from the CCB's fixed pseudorandom sequence.


next up previous
Next: PORT Table Up: gbtCCBFits Previous: Overview
Bob Garwood
2011-07-23