Overview of the WXM flight software use

The HETE WXM flight software is a collection of programs that run on two microprocessors in the HETE satellite or pizza box (one transputer and one Motorola 56001 DSP), and on UNIX systems on ground. Their purpose is to receive data from the Wide field Xray Monitor (WXM) instrument on the HETE satellite, do scientific data analysis on board, send the data to ground and analyze the data on ground. There is also a simulation program that runs on another DSP in the pizza box. This program generates simulated photons, which are then transmitted vi a real serial link (via the capellini device) to the other DSP.

The programs are (in a kind of "software pipeline ordering"):

• tdsp: runs on the gamma DSP when we use the pizza box. Generates photons with reasonable values for energy, position,
• xdsp: runs on the xray DSP. This processor talks to, commands and gets data from the WXM instrument.
• xg transputer: receives data from xdsp and from the gamma ray instrument DSP, looks for triggers, reconstructs images, and handles telemetry formatting of the data.
• wxm archiver: runs on ground. Receives data from the CNS and simply writes the IPP messages into a file, invoking fwrite() on the header and then the body of the message.
• wxm putsd: runs on ground. This is a daemon process that receives debugging messages from the flight processes, and displays them to standard output. This allows a "printf" type of debugging to be done from the satellite, as long as the RF link works.
• wxm read_archive: runs on ground. Extracts data from the archive file generated by archiver, and presents it in 3 different modes, for "quick summary", "long summary" and "good for pipelining with real analysis tools".
• Nobu Kawai's wxm GSE software: this uses the "raw data" product from xdsp, and allows a serious analysis of the data with a NeXTstep GUI.
• hete-wxm.scm: software written for GNUDL (the GNU Data Language) which gives snapshots of the WXM data. (Still in early phase.)

Note: read_archive will be replaced by a more elaborate software pipeline, including a program to split the data by time period and by satellite reboots, and a program that does a totally simple data extraction. The current read_archive grew too much and got too fancy.

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