The most important header parameters are defined by default as SIC variables in a protected mode. The others, of less frequent use, can be accessed if required by the user (see ``Advanced Processing''). The default variables are (RW means Read-Write variable, RO, Read-Only).

TELESCOPE Character*12, RW, Telescope name NUMBER Integer, RW, Observation number VERSION Integer, RO, Version number DATATYPE Integer, RO, Type of observation 0 Line, 1 Continuum, 2 Skydip QUALITY Integer, RO, Quality of data SCAN Integer, RO, Original scan number UTOBS Double, RO, UT of observation (Radians) LSTOBS Double, RO, LST of observation (Radians) AZIMUTH Real, RW, Azimuth of observation (Radians) ELEVATION Real, RW, Elevation of observation (Radians) TSYS Real, RW, System temperature TIME Real, RW, Integration time (Seconds) SOURCE Character*12, RW, Source name LAMBDA Double, RW, Longitude of source (Radians) BETA Double, RW, Latitude of source (Radians) OFF_LAMBDA Double, RW, Offset in longitude (Radians) OFF_BETA Double, RW, Offset in latitude (Radians) EQUINOX Real, RW, Equinox of coordinates (Years) LINE Character*12 RW, Line name CHANNELS Integer, RO, Number of channels REFERENCE Real, RW, Reference channel FREQ_STEP Real, RW, Frequency step by channel (MHz) VELO_STEP Real, RW, Velocity step by channel (km/s) VELOCITY Real, RW, Velocity of reference channel FREQUENCY Double, RW, Rest frequency at reference channel IMAGE Double, RW, Image frequency " " " " BEAM_EFF Real, RW, Telescope beam efficiency FORWARD_EFF Real, RW, Telescope forward efficiency GAIN_IMAGE Real, RW, Image to signal band ratio WATER Real, RO, Water vapor content (mm) PRESSURE Real, RO, External pressure (hPa) AMBIENT_T Real, RO, External temperature (K) CHOPPER_T Real, RO, Chopper temperature (K) COLD_T Real, RO, Cold load temperature (K) TAU_SIGNAL Real, RO, Opacity in signal band TAU_IMAGE Real, RO, Opacity in image band ATM_SIGNAL Real, RO, Atmospheric temperature in signal band ATM_IMAGE Real, RO, Atmospheric temperature in image band RX Real[8192] RO, X values of data points RY Real[8192] RW, Y values of data points8192 is currently the maximum size of the spectra, but the variables RX and RY are redimensioned to the effective number of channels for each spectrum.

Gildas manager 2018-08-19