@misc{indiciae6a295e9b780a,
  title = {Helicopter Airborne Laser Positioning System (HALPS)},
  author = {Eppel, Joseph C. and Christiansen, Howard and Cross, Jeffrey and Totah, Joseph},
  year = {1990},
  url = {https://ntrs.nasa.gov/citations/19900014083},
  note = {Source identifier: 19900014083}
}