| Description: The identifier of the detector(s) used to define the targeting of this observation. For instruments with multiple detectors, this attribute indicates the one that is most likely to contain the intended target. When an observation was planned to employ more than one detector to encompass the target, this attribute will have multiple values. For instruments that do not have multiple detectors, this attribute will have a single value equal to that of channel_id and detector_id. For WFPC2, this attribute is derived from the value of the aperture: - PC1 for apertures PC1, PC1-FIX, POLQP15P, FQCH4P15; - WF2 for apertures WF2, WF2-FIX, FQUVN33, POLQN33, POLQN18, POLQP15W, FQCH4NW2, FQCH4N33; - WF3 for apertures WF3, WF3-FIX, FQCH4NW3, F160BN15; - WF4 for apertures WF4, WF4-FIX, FQCH4NW4; - All four for apertures WFALL, WFALL-FIX; - PC1 and WF3 for aperture FQCH4N15.** These are found in in Table 3.14 of the WFPC2 Instrument Handbook, Version 10.0. Note that they often appear in FITS lab (**Note: aperture FQCH4N15 was targeted relative to PC1, but was often used to position the methane 0.89 micron quad filter atop the WF3 chip as well.) For ACS/WFC, most aperture values begin with either "WFC1" or "WFC2", which indicates which of the detectors was used for targeting. Apertures WFCM, WFC, WFC-FIX, and WFCENTER are associated with both. For WFC3/UVIS, most aperture values begin with either "UVIS1" or "UVIS2", which indicates which of the detectors was used for targeting. Apertures UVIS, UVIS-CENTER, UVIS-FIX, UVIS-IR-FIX, G280, and G280-REF are associated with both detectors. The targeting of the UVIS-QUAD, UVIS-QUAD-FIX, and UVIS-QUAD-SUB apertures is are determined based on the value of the selected quad filter: UVIS1 for filters FQ378N, FQ387N, FQ437N, FQ492N, FQ508N, FQ619N, FQ674N, FQ750N, FQ889N, and FQ937N; UVIS2 for filters FQ232N, FQ243N, FQ422M, FQ436N, FQ575N, FQ634N, FQ672N, FQ727N, FQ906N, and FQ924N. (See Table 6.4 of the WFC3 Instrument Handbook.) For WFPC, this is derived from the aperture value: - WF1 for aperture W1; WF2 for aperture W2, etc. - PC5 for aperture P5; PC6 for aperture P6, etc. For COS/FUV, this attribute will always match the value(s) of detector_id. |