Low Level Processing Data Products

As it was explained in Section 3.1 JEM-X has five different telemetry formats: Full Imaging, Restricted Imaging, Spectral/Timing, Spectral and Timing. The information sent to ground in Restricted Imaging mode is enhanced with the count rate of the events. The time resolution of these Count Rate data is 125 ms, while the rate of the image transfer in this mode depends on the brightness of the source and may be up to 32 seconds for the faintest ones, see Table 2 for an overview.

During data taking JEM-X instruments can switch autonomously between two preplanned modes according to the fill status of an on-board buffer, thus avoiding data loss due to the buffer overflow, if the secondary mode allows higher transmission rate.

In addition to the mode switching there is also a grey filter mechanism which can reduce the telemetry load by rejecting a given number (up to and including 31) out of 32 hardware triggers. The value of the grey filter setting can vary from G=31 (all events are accepted) to G=0 (only one event from each 32 is accepted). In general, value G of grey filter means that 31-G events from 32 are rejected.

Table 26 summarizes all scientific data structures created in these modes. The data structures for JEM-X 1 and JEM-X 2 have the similar names, so to avoid the unnecessary repetition we write JMXi, where it should be replaced by ``1'' or ``2'' depending on the instrument.

Table 26: List of JEM-X RAW, PRP and COR Data Structures

Telemetry Format	Raw	Prepared	Corrected
	Data Structure	Data Structure	Data Structure
	Contains RAW	Contains	Contains Corrected
	event/spectral data	event/spectral OBTs	event/spectral data
Full Imaging	JMXi-FULL-RAW	JMXi-FULL-PRP	JMXi-FULL-COR
Restricted Imaging (REST)	JMXi-REST-RAW	JMXi-REST-PRP	JMXi-REST-COR
Count Rate for REST	JMXi-RATE-RAW	JMXi-RATE-PRP	JMXi-RATE-COR
Spectral/Timing	JMXi-SPTI-RAW	JMXi-SPTI-PRP	JMXi-SPTI-COR
Timing	JMXi-TIME-RAW	JMXi-TIME-PRP	JMXi-TIME-COR
Spectral	JMXi-SPEC-RAW	JMXi-SPEC-PRP	JMXi-SPEC-COR