AIRS

Frequently Asked Questions


Back to FAQ list

Q.  Is the error estimate, emisIRStdErr, merely a sort of error bar or is
the estimated error actually this value? In that case, what is the sign
of the error? In the .hdf files that I have looked at, the value for
emisIRStdErr is always positive.   

A.  The emisIRStdErr is a propagated error estimate. We start with a
first guess error (of approximately 0.1) and attempt to reduce it
based on residuals of our formal retrieval algorithm. The result is
unsatisfactory, and we have not provided an empirical estimate to
compensate. The emisIRStdErr is used internally in the algorithm but
does not have a satisfactory case-by-case skill. It is a standard
error in an RMS sense, and thus is always positive.

The surface emissivity algorithm, particularly over land, is a prime
target for improvement in our refinement of the future V6 algorithm.

Back to FAQ list