We propose a dense network of dual-mission HF radars costing $300 – PiRadar costs 95% less than contemporary radar nodes using the latest COTS SDR technology, simultaneously:
- improving ionospheric models via measurements as an alternative or complement to GNSS TEC measurements
- 4-D imaging of the Earth’s atmosphere/ionosphere
- data relay from isolated sites (e.g. flood alarm, tracking animals)
- Solar storm impact detection and quantification
- Ground-based GPS time-transfer and location service alternative
A simplified system using one antenna for transmit & receive is shown below. Also shown in this figure is a means to inject 1PPS directly into transmit and receive RF streams, in case there is an issue with hardware triggering of DAC or ADC–applicable to general receivers such as RTL-SDR. In this diagram, a maximum 20 dBm transmit power is assumed.
|PiRadar performance metric||value|
|range resolution||1..25 km|
|data rate||1..20 kbps|
|transmit power||1..100 mW|
|transmit bandwidth||6 kHz..1 MHz|
|node-to-node communication range (skywave)||50..500 km|
Prior Work in HF sounding networks
Tiddbit CW HF oblique sounder works in the 2..10 MHz range, transmit power ~ 100 watts.