To determine the location of GZ when two or more observers report their

location and both report a flash-to-bang time but no azimuth, plot the

observers' locations on the map. You then determine the distance to GZ

based on the flash-to-bang time using the nomogram (Figure A-2, page 3,

Supplemental Booklet) or the mathematical method.

Using a drawing

compass or a piece of string measure the distance to GZ on the Graphic

Scale of the map.

From each observer location draw an arc at the

computed distances. GZ is considered to be at the point where the arcs

intersect (Figure 1-4).