38#define SDFITS_COLUMN_FREQRES (dsp_fits_column){"FREQRES", EXTFITS_ELEMENT_DOUBLE.typestr, EXTFITS_MEASURE_UNIT_HZ, "", "resolution may differ from spacing of backend, not one channel", (char*[]){""}}
43#define SDFITS_COLUMN_TIME (dsp_fits_column){"TIME", EXTFITS_ELEMENT_DOUBLE.typestr, EXTFITS_MEASURE_UNIT_SECOND, "", "UT time of day; UT seconds since Oh UT", (char*[]){""}}
181#define SDFITS_COLUMN_TAUZENIT (dsp_fits_column){"TAUZENIT", EXTFITS_ELEMENT_DOUBLE.typestr, EXTFITS_MEASURE_UNIT_PERCENT, "", "Opacity per unit air mass", (char*[]){""}}