Observers may forget that some frames lost due to missing
synchronisation. There is no synchronisation between the readout of
the detector and the satellite or wheels motions. As a result, at
least one frame is lost at the beginning or at the end of the
integration in a given configuration/position. In the manual we
mentionned that, for security purposes, the logic would add two
frames, one at the beginning and one at the end, to each integration
in a given configuration. It does not do that, and so you have to do
it. Thus if you require N
frames to be taken either per raster
point, or per CVF step, or per beamswitching cycle, you must actually
enter in the PGA the following
N(Total):
Note that these formulae are conservative and slightly overestimate the
number of synchronisation frames necessary. Note also that ISOCAM's
simulator takes them into account to compute the observing time
(
axis on the graph), but as you are required to enter N in the
PGA, and not T
, you have to include these synchronisation
frames.