Measuring the doppler shift of WWVB during a flight
18 days ago
- #Radio
- #WWVB
- #HackRF
- HackRF Pro can receive WWVB time signals at 60 kHz, below its advertised 100 kHz lower limit.
- WWVB provides a stable frequency reference and time code, useful for radio-controlled clocks and lab standards.
- HackRF Pro's TCXO offers better frequency accuracy than HackRF One's XO, reducing uncertainty from 10-20 kHz to 1-2 kHz at 1 GHz.
- WWVB disciplined oscillators are a cost-effective alternative to GPSDOs and atomic clocks, with advantages like indoor use and simpler design.
- Teewee, an active loopstick antenna, was designed to receive WWVB signals, overcoming challenges like PC interference.
- WWVB's signal includes ASK and BPSK modulation, carrying time and status information in 60-second frames.
- Doppler shift from aircraft motion was observed in WWVB signals, confirming the HackRF Pro's frequency accuracy.
- The Teewee design is open for others to build, compatible with HackRF Pro and, to a lesser extent, HackRF One.