U4. Map generator Function

U4. Map generator
Date: 23 April 2002 (draft v1)
Contributors: S. Digel (SU-HEPL)
This module constructs binned maps of gamma rays (‘counts’), exposure, and intensity
from the output of the Event data extractor (U1) and the Exposure Calculator (U3).
Calculations of exposure maps will likely involve interpolation of exposures calculated
for the standard tessellation grid.
Coordinate gridding of the maps and coordinate projection.
Parameters to be ‘marginalized’ (integrated over)
Gridding of the remaining parameters (e.g., energy or inclination angle)
Data set produced by the Event data extractor U1
Exposure matrix produced by the Exposure calculator U3
Databases required
Counts and/or exposure maps (perhaps multidimensional). The intensity map, i.e., the
ratio of counts and exposure, can be calculated as well. All output must include (in a
header) the specifications of selection criteria used (for the input gamma-ray and
exposure datasets) as well as of the parameters marginalized as part of the map
Performance Requirements
TBD. The map generation is not likely to be computationally intensive.
Other Modules Required
Host Environment:
Run on central server or client computer.
Existing Counterparts
None. The EGRET analogs, MAPGEN (counts maps) and INTMAP (exposure and
intensity maps), are based on single viewing periods,
Open Issues for Definition or Implementation
1. What coordinate systems should be supported? Systems other than in the photon
2. What coordinate projections should be supported?
3. Will any analysis tools require as input any of the maps generated here as input? Or
will the maps primarily be for visualizations?