The Fixed Site Radio Direction Finder
Our fixed-site direction finders deliver precise angle-of-arrival measurements from permanent or semi-permanent installations. A single site—such as those commonly used in air traffic control—provides an accurate azimuth bearing toward the source of a radio transmission. When multiple fixed sites are deployed across a geographic area and networked to a central computer, they can produce instantaneous and highly accurate geolocation estimates of RF emitters. These systems are ideal for a wide range of applications, including public safety and homeland security monitoring, interference hunting, maritime vessel location, stolen vehicle recovery, and general RF surveillance.
A fixed-site radio direction finder typically includes one or more DF antennas, a DF processor, and a narrow‑band FM receiver. Our antennas cover a wide frequency range: VHF (115–250 MHz), UHF (250–500 MHz), and THF (500–1000 MHz). We offer complete fixed‑site systems in either a portable packaged configuration or a permanent rack‑mount installation. Individual components are also available, allowing you to build a customized DF setup to meet your specific requirements.
Multiple direction finding processors and receivers may be connected to a single DF antenna to provide simultaneous measurements of bearings on up to 32 frequencies.
We also provide Windows‑based software that fully integrates with our fixed-site direction finders. The software allows users to configure each direction finder, visualize bearings in real time on a map, and by combining the bearings from multiple locations, the software automatically generates an accurate estimate of the RF signal’s position.
Specifications for Our Direction Finders
| Specifications | |
| RDF Method | Synthetic-Doppler with “Smooth Summing” |
| Frequency Range | 115 – 1000 MHz |
| Accuracy | < 1 deg rms (115 – 500 MHz) |
| < 1.6 deg rms (500 – 1000 MHz) | |
| Resolution | 0.1 deg |
| Sampling Rate | 2 samples per second |
| Sensitivity | -123 dBm (FM receiver dependent) |
| Averaging | Adjustable from 1 to 20 samples |
| RF pulse detection | 100 ms minimum |
| Commutation frequency | Adjustable (250, 500, 1000, 2000 Hz) |
| Voltage Range | 11 – 14 VDC |
| Power | 6.5 W @ 12 VDC (processor and antenna) |
| Temperature Range | -25 °C to 85 °C (antenna) |
| CE Compliant | Per EN 61000-6-2, EN 61000-6-4 AND EN 301 489-1 |
Get Started
To get started with your fixed site radio direction finder, please contact us. We are happy to help you!