KrakenSDR : SDR Receiver for Direction Finding with 5x Gonio Antennas

• Number of channels: 5 SDR receivers (compared with 4 for KerberosSDR).
• Receiving frequency: 24 MHz to 1.766 GHz. Nominal from 100 to 1000 MHz.
• Sampling rate: 2.56 MHz per channel.
• Oscillator stability: 1 PPM, for perfect synchronisation.
• Power consumption: 5 V, 2.2 A (11 W) via USB-C (requires adapter or compatible battery not included).
• Advanced hardware design:
  • Active and passive cooling for use down to 50°C.
  • Robust casing with electrostatic discharge (ESD) protection.
  • Integrated bias tees (4.5 V) to power external RF components such as LNAs.
• Software support: Compatible with KrakenSDR Direction Finding, GNU Radio, Heimdall DAQ, and other open-source tools.
• Platforms: Raspberry Pi 4, PC (Linux and Windows).

Antennas :

Pack of 5 VHF-UHF magnetic antennas included, with 2m SMA male cable.

Applications :

• Locating RF signals, interference or illegal transmitters.
• In-vehicle direction-finding for searching or tracking assets.
• Tracking beacons for wildlife, equipment or rescue operations.
• Amateur radio experiments: fox hunting, repeater monitoring, etc.
• Radio astronomy and scientific studies using interferometry.

Features :

• Fully automatic calibration, eliminating manual handling.
• Improved cooling for reliable performance in closed environments.
• Surge and ESD protection for increased durability.
• Accurate signal mapping with dedicated Android app.

Design and ergonomics :

• Dimensions: 177 mm x 112.3 mm x 25.86 mm (+4.7 mm for fan grill).
• Weight: 670 g case only
• SMA ports: 5 RX inputs (CH0 to CH4).
• Status LEDs: Indicate power supply, channel activity and internal noise status.

Documentation, support and wiki available at https://github.com/krakenrf/krakensdr_docs/wiki

A forum is available for technical support at: https: //forum.krakenrf.com/

Direction finding and electromagnetic wave localization

Direction finding is a method used to determine the direction of arrival of an electromagnetic wave. Based on physical principles such as antenna directivity, interferometry and the Doppler-Fizeau effect, it has a wide range of applications in navigation, electronic warfare, radio spectrum monitoring and even sporting activities.

Examples of applications

1. Navigation
   In maritime and air navigation, direction-finding is used to locate a receiver in relation to fixed transmitters, such as beacons or radio beacons.

   • It is used to plot a position by triangulating the signals from two transmitters.
   • A technique called homing makes it possible to reach a specific port or point using a single transmitter.

   Historically, ships and aircraft used this technology before the advent of GPS, although it required a trained operator to correct propagation anomalies linked to atmospheric or environmental conditions.

2. Electronic warfare
   In a military context, direction-finding is used to locate hostile transmitters, such as radars, radios or missile homing beacons. This can be done :

   • By triangulation using several receivers at different points.
   • By calculation according to the movements of the receiver.
     
     
3. Search and Rescue
   In France, the SATER (Sauvetage Aéro-Terrestre) plan uses direction-finding to locate civil or military aircraft in distress. Direction finders such as ADFs (Automatic Direction Finder) are built into aircraft to detect emergency signals.
   
   
4. Radio Spectrum Surveillance
   Government agencies use direction finding to monitor the use of radio frequencies and detect unauthorised transmissions.
   
   
5. Amateur Radio and Sport
   Amateur radio operators use this technology for leisure or competition, as in the sport of foxhunting, where participants locate radio beacons.
   
   
6. Ecological monitoring
   In wildlife protection, miniaturised transmitters are used to track the movements of animals, helping to preserve them or study their behaviour.

Despite competition from more modern technologies such as GPS, direction-finding remains a useful tool in these specialist fields.