  GRAND is an array of position sensitive proportional wire chambers (PWCs)
located at 86.2 degrees W, 41.7 degrees N at an elevation of 220 m adjacent to
the campus of the University of Notre Dame with 82 square meters of total muon
detector area. The geometry of the PWCs allows the angles of the charged
secondary muon tracks to be measured to +/- 0.3 deg in each of two orthogonal
planes. Muons are 99% differentiated from electrons by means of a 51 mm steel
plate in each detector.
