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NICMOS Science Data
One of the major differences the user will find compared to existing instruments on-board HST is that NICMOS (and STIS) data delivered to the observer contains not only the images obtained, but also have variance and quality arrays for each of them. On a pixel by pixel basis these give the statistical uncertainty in the data, and flags identifying any abnormalities in the data respectively. In the case of RAMP mode, as we describe in the Appendix, the variance array is created on board. For the other three modes of operation, these arrays are constructed in the analysis in the ground processing systems (pipelines). For NICMOS data there will be an integration time and a number of valid samples images for each dataset. All the data the user will see will contain all five of these components for each image in a dataset.
See Chapter 13 for a detailed discussion of the NICMOS data products.
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Last updated: 07/24/97 15:32:59