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Flux calibration

Data are flux calibrated by multiplying by the default flux calibration files referred to by logical names cal1 and cal2, there is no flux calibration for third order at present. Use FMULT, and you will have relative fluxes at the base of the earth's atmosphere. Fluxing is to be recommended, as it makes it easier to recognise features in the raw spectrum at wavelengths where the CCD sensitivity is falling off. It must be made clear though, that there is no substitute for taking observations of standard stars, and fluxing your data using the routines contained in say FIGARO. To get absolute fluxes, account must be made of atmospheric extinction; LPO Technical Note 31 details how to do this.