[ Discussions | TOC | Search | Post | Reply ]
From: Gar Bering
Time: 10:43:57 AM
Remote Name: 22.214.171.124
1. The dipole moment change suggestion is easy enough in that we very well calibrated electric field detectors, but hard in that the translation from delta p to delta E is strongly range dependent. A positive delta E > 1 V/m in 1 millisecond works at ranges greater than 45 km. Inside 45 km a negative delta E < -10 V/m in 1 ms works. Since we don't know the range, use both and TM which was the trigger. When we have a better sense of what the calibration is on the on-board flash detector, we can use add a flash threshold criterion to each of these to discriminate.
2. For the delta B trigger, we have a two choices of on-board low-pass filter in the search coil receiver, < 300 Hz and < 4 kHz. We have chosen to use the latter. For reasons of computaional speed (the trigger detect subroutine has to execute in 600 microseconds)we are using threshold level detection on each component separately, rather than try to compute a square root.
3. We have put in an uplooking flash detector trigger. The choice of threshold needs to be refined based on flight experience.
4. We still have an unresolved interrupt conflict between the fast ADC and the PCM that may keep us from implementing anything on the test flight.