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.