Calculates the area coverage of an instantaneous chemical point source and produces downwind and crosswind field coordinates for three dosage contours of interest.

One means of predicting the hazard area generated by an instantaneous (explosive) vapor or aerosol release of a toxic chemical is to mathematically model the resulting cloud as a 3-dimensional normal distribution evolving over time, otherwise known as a gaussian plume model.

The model implemented here was developed in 1987 by the Canadian Defence Research Establishment Suffield, Ralston, Alberta as the standard NATO Allied Technical Publication ATP-45 algorithm for calculating chemical hazards.

In this project, we have converted the FORTRAN code to more modern Microsoft C#, and have validated the code with unit tests described by criteria in Suffield Memorandum No. 1275, Appendix A. That document and its accompanying code was approved for unlimited public release on November 30, 1989, by the United States Defense Technical Information Center.