SOURCE(header/script) DBNAME value description
QC.EFFWAVE spec_cal_effwave 1.6e-6 effective central wave
QC.EFFBAND spec_cal_effband 4.32e-8 effective band
QC.EFFWAVE.PTP spec_cal_effwave_ptp 4.3e-8 effective central wave variation between the baselines (peak to peak)
Description of algorithms:
This measures the effective wavelength of each spectral channel
by measuring the actual fringes spacing for long scans.
This is only possible if the internal piezo scanner is well calibrated/known and linear
Data can be taken on sky (used to calibrate sky data).
or on the internal lamp (HC).
using the Fourier Transform Spectrometry of the fringes