2.7.0 spase://HamSCI/Instrument/PSWS/Grape1DRF/KD6O-1 HamSCI GRAPE 1 DRF (Doppler Radio Frequency Receiver for the Great Radio Amateur Propagation Experiment) at KD6O-1 station GRAPE 1 DRF at KD6O-1 station 2025-09-04T10:00:00 GRAPE 1 DRF (Doppler Radio Frequency Receiver for the Great Radio Amateur Propagation Experiment) is a citizen science instrument that receives HF time-standard signals (e.g., WWV, WWVH, CHU) to measure Doppler shifts caused by ionospheric dynamics. Data is collected by volunteers using software-defined radios and GPS-disciplined oscillators, recorded in Digital RF (DRF) format, and contributed to the HamSCI Personal Space Weather Station (PSWS) repository for space weather research. The KD6O-1 is located at 38.604ºN, 121.292ºW. Instrument type is Grape 1 DRF (Grape_1_12). There is one antenna at this station, which is Antenna 1: Pixel loop. It records 10MHz Doppler Shift. spase://SMWG/Person/Nathaniel.Frissell PrincipalInvestigator spase://SMWG/Person/William.Engelke TechnicalContact spase://SMWG/Person/Kornyanat.Hozumi MetadataContact Experiment HamSCI Personal Space Weather Station (PSWS) 2023-09-01T00:00:00 2024-07-25T00:00:00 spase://HamSCI/Observatory/HamSCI