How can I recover the true incident flux modulation?
Use the hsi_demodulator routine provided by G. Hurford. It is located in $SSW/hessi/idl/util. See the routine header for calling arguments. hsi_demodulator works reasonably well with some important caveats. The constraints are: • As with any x-ray light curve, RHESSI light curves have the usual Poisson statistical limitations. With RHESSI there is an additional ~20% rms fluctuation (if averaging over ~8 detectors) due to the modulation. The demodulator removes most of this 20%, but at the price of discarding ~1/2 of the counts which increases the statistical component of the error by sqrt 2. Therefore at low count rates, the demodulator makes things worse; at high count rates it certainly helps. • The time resolution should be <<1s since there is an assumption that the modulation period is fixed over the the time resolution interval. • Because of the statistical limitations, the time resolution should be at least ~20 milliseconds. 0.1 to 0.25 s seems to work well. Shorter time resoluti
