Appendix 16. LAN PHA Documentation (continued)

 

A16.2 Inputs

 

Inputs to the program PHAGEN consist of the LAN archive file(s), various control parameters, and PHA and channel map files. All input files are required.

 

Assumptions: PHAGEN assumes the following logical name assignments:

 

landisk:	disk and directory for the PHA and channel maps. For VAX, the assignment statement is landisk:==diskm::[dirmaps] where diskm is the lan map disk name and dirmaps is the name of the directory containing the map files.
landata:	disk and directory for the output data sets created by PHAGEN. The VAX assignment statement is landata:==disko::[diroutput] where disko is the lan pha output data disk name and diroutput is the name of the output data directory.

 

A16.2.1 LAN Archive File

 

The LAN archive file is the primary input file. This file is produced during the LAN archive process and is described in the LAN Archive Records Description document by Tom Armstrong. The detailed description will not be repeated here. The archive file should be accessible from either disk or tape, but this is an installation dependent I/O task. If the archive files are on disk, the files are accessed from file laninput:ULAyyddd.LAN unless the user specifies a different input archive file name.

 

The LAN archive file contains several record types, all containing a common header block. The PHAGEN program will select only those archive records labeled as 'PHAR' or 'MFSA' for processing. The PHAR records drive the accumulation of the track and PHA data sets. The MFSA data records drive the accumulation of the MFSA data set.

 

The archive header block contains many parameters including time, spacecraft ephemeris, instrument voltages, and magnetic field data. The header block data is stored for the beginning and ending times of each record produced by program PHAGEN. With the exception of time bounds checking and saving the beginning and ending header data, there is no processing per se with the header block.

 

Archive records labeled as PHAR contain the PHA event history of the time period covered by the PHAR records. This history is comprised of up to 1024 individual events, each event containing measured delta E and E parameters, sector and time. In addition, the record contains the eight broad channel count rates and times for the time period synchronous with the accumulation of the event history. These rate channels are referred to as the WART channels in the LAN Archive Description document. These rates are used to normalize the accumulated track and pulse data.

 

Archive records labeled as MFSA contain the sectored, 32 energy channel spectral counts and sample times for each of the four detectors F', F, M', and M, for the time period covered by the MFSA records. The F' and M' detector spectra contain 8 sectors while the F and M detectors contain only 4 sectors. Similar to the PHAR records, the MFSA records also contain time synchronous rate channel data for each detector. These broad channel rates and times are used to normalize the low duty cycle MFSA data.

 

A16.2.2 Control Parameters

 

The program PHAGEN is controlled via run time parameters supplied by the user. These parameters should be able to be entered from the keyboard or from a file. Currently, PHAGEN is configured to prompt the user for the run time parameters and accept these parameters from the keyboard. The parameters required by PHAGEN are:

 

• Time bounds for the run. Begin and end time are required in the format yy,ddd,hh,mm,ss. Trailing zeros may be omitted. Default times are read from the file named "timebounds.dat" in the default run time directory. The user may choose the default times, change the default times, or run with a different set of time bounds.
• Average intervals for the track, PHA and MFSA ouput records in hh,mm,ss format. In addition, PHAGEN produces PHA and MFSA records containing 4* average intervals. For LAN PHA and MFSA production, the probable average interval(s) will be 6 hours (and 24 hours). Note: The user must select a PHA average interval which is an even multiple of the track average interval.
• Archive file name if different than the default file name.
• Outputs desired from PHAGEN. Either the pulse data set or the track and MFSA data sets may be suppressed.
• Which WART channels are processed? All (0) or any subset of the WART channels may be selected for processing. Any events in a WART channel not selected for processing are skipped.

 

A16.2.3 PHA Map

 

The PHA map input file to program PHAGEN contains a map of the 256 x 256 pixel PHA space for the LAN CA experiment. The map contains species and energy bin numbers for each event pixel in the map. This map is used to identify an event as a particular species belonging to a particular energy bin during the accumulation phase of the track data set. The energy bins are described in the PHAGEN output description for the track data set.

 

The species energy map is contained in the file named "landef:lantracksnnn.def" where nnn is the version number of the map desired. The map is a 256 x 256 byte array with each byte containing species and bin number encoded using 4 bits each. The low four bits (bits 0-3 on VAX) are the energy bin number of the pixel, and the high four bits (bit 4-7 VAX) are the species number.

 

A16.2.4 Channel Map

 

The channel map input file to program PHAGEN contains a map of the 256 x 256 pixel PHA space for the LAN CA experiment (similar to the species energy map). The channel map contains the channel number of each event pixel in the map. This map is used to identify the channel number of an event location during the normalization phase of the pulse rate process.

The channel map is contained in the file named "landef:lanchannels.def". The map is a 256 x 256 byte array where each byte contains the channel number of the event location. The channel numbers are defined as 1 through 8 representing W1 through W8 and 0 as undefined channel.

 

 

Next: A16.3 Outputs

 

Return to Appendix 16 Table of Contents