Preliminary Requirements

• XPOSE runs in an Open Windows environment.
• XPOSE references the following files

  1.

  $MISC_DIR/timeline - File of valid GRO observation periods.

  2.

  $EGRET_PROGRAMS/sequence/scale.factor - Contains recommended scale factors for each viewing period.

• Various files in $CALIB_DIR are used for the sensitive area calculation.
• Exposure history files are read from $EXPHST_DIR.

where $MISC_DIR, $EGRET_PROGRAMS, $EXPHST_DIR are environmental variables with the names of appropriate directories or file.