TY  - RPRT
TI  - Computer program to predict visibility of global positioning system (GPS) satellites using an IBM-PC or compatible microcomputer
AU  - J. T. Gann
PY  - 1987
DO  - 10.3133/ofr87274
UR  - https://pubs.usgs.gov/publication/ofr87274
ID  - ofr87274
ER  -