@misc{indiciae2175a85350c6,
  title = {Imaging the Ionosphere with the Global Positioning System},
  author = {Kursinski, E. and Ibanez-Meier, R. and Hajj, G.},
  year = {1994},
  url = {https://ntrs.nasa.gov/citations/20210001628},
  note = {Source identifier: 20210001628}
}