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How to compute the approximate SNR of an AOT SWS01 observation

 

The following algorithm may be used to compute the SNR to be expected for a source with a given flux density:

Determine the detector reset time tex2html_wrap_inline2408 required to achieve the desired SNR:
a) Convert the expected flux density at the desired wavelength to a detector signal S ( tex2html_wrap_inline2404 V/s), using the spectral response curves shown in Fig. 5.3 (p. gif) to Fig. 5.8 (p. gif).
b) Compute the expected SNR per resolution element, starting with the minimum detector reset time of tex2html_wrap_inline3083 sec, using the formula

displaymath3075

where tex2html_wrap_inline2930 stands for the number of integrations per resolution element as given in Tab. 6.3, and taking the noise parameters tex2html_wrap_inline3087 from Tab. 5.2 (p. gif).

If the expected SNR is less than requested, repeat the computation of the expected tex2html_wrap_inline3089 with the maximum detector reset time of tex2html_wrap_inline2402 sec, as indicated in Tab. 6.3.



SWS Consortium
Wed Aug 7 17:20:29 MET DST 1996