Two 150-MHz coherent radar depth sounders were developed and flown over the Greenland ice sheet to obtain ice thickness measurements in support of PARCA investigations and the North Greenland Ice Core Project. These radar depth sounders are designed to use pulse compression techniques and coherent integration to obtain the high sensitivity required to measure the thickness of more than 4 km of cold ice. These systems are used to collect radar data over the interior and margins of the ice sheet and several outlet glaciers. Both radar systems are operated on the NASA P-3B aircraft equipped with GPS receivers. Radar data are tagged with GPS-derived location information and are collected in conjunction with laser altimeter measurements. All data collected from 1993 to 2014 have been processed, and ice thickness was derived with an accuracy of ± 10 m over 90 percent of the flight lines flown as a part of the PARCA initiative. Radar echo grams and derived ice thickness data are available via FTP.