Bandpass and detector identification

The bandpass in which the measurement is made must be identified. The bandpass name is recorded in a column labelled BAND. (This name, combined with the information in the instrument file, is used to identify the detector in multichannel instruments.) Standard passband names should be used: 'V', 'B', 'U', 'URL', 'R', 'I', 'u', 'v', 'b', 'y', 'betaW', etc. These should agree with the notation used for standard indices for the standard stars (see section I.2, above, which describes standard-star table files). Standard band names are also listed in subsection I.5.3, ``Passbands''.

For DARK measurements, a digit must be appended to indicate the detector number, if more than one detector is used: DARK1, DARK2, etc. If red leaks are measured for two or more passbands, they must be plainly marked; e.g., 'URL', 'BRL', etc. If ``neutral'' filters are used to measure nonlinearity, as is often done with pulse-counting systems, the appropriate suffix 'ND' (for a single attenuator), or 'ND1', 'ND2', etc., should be appended to the BAND value.

Often a filter position is carried in the original data as a code. Such information must be decoded to a standard band name in the observation-table file. The decoding information is normally found in the instrumental table file.