The Project GRAND array is located in a 100 m x 100 m field adjacent to the Notre Dame campus at 222 m elevation, 86 deg W and 42 deg N. The 64 stations are arranged in an 8 x 8 grid with 14 m separation between stations. The electronics trailer at the center of the field was used by our astronauts and was obtained from NASA government surplus. The southwest quadrant was the first constructed; these stations were placed 0.6 m into the ground for natural cooling in the summer. The cooling works well, but moisture problems suggested the placement of the rest of the array above ground with added insulation. The detectors are most sensitive to particles in the 10 to 500 GeV range with peak detector sensitivity at 56 GeV, meaning that Project GRAND's detectors are ideal for studying solar gamma ray astrophysics.
Figure 3.4 from the thesis presentation of C. D'Andrea