Fixed Means


Fixed Direction Finder


  • Direction Finder is intended for search, evaluation of parameters, direction finding, recording, technical analysis and classification of signals within HF, VHF, UHF and SHF ranges as a part of ARCHA-IN Unattended Fixed Radio Monitoring Station and ARTIKUL-SN System, as well as for localization of their emitters while operating as a part of direction finding network.

Antenna system of ARTIKUL-S Direction Finder

Antenna system of ARTIKUL-S Direction Finder

Typical Configuration:

  • Mast mounted DF antenna system (operating frequency range 20-3000 MHz)
  • Analog-digital processing unit
  • Power supply unit
  • Automated workstation (AWS) with SMO-PPK, SMO-STA, SMO-ASPD Software Packages.


  • Extension of DF frequency range extension (1.5 – 8000 MHz)
  • Extension of simultaneous DF bandwidth up to 24 MHz
  • Mast
  • SMO-PVP Cross Talk Detection Software Package
  • ARC-GIS Geoinformation Server.

Structural Diagram of ARTIKUL-S Direction Finder

Features of Direction Finder:

  • Radio receiver is installed inside DF antenna system providing for high interference protection, sensitivity and DF accuracy
  • To prevent digital path overloading of the direction finder with simultaneous bandwidth of 24 MHz in complicated electromagnetic environment, digital radio receiver includes additional analogue path with 500 kHz bandwidth
  • The weight of antenna system doesn't exceed 40 kg
  • The distance between antenna systems and operator's location can be up to 100 m
  • Joint operation of several Direction Finders.

Direction Finder Provides:

  • Panoramic spectrum analysis within the entire operating frequency range or within separate intervals in complicated electromagnetic environment, accommodation to ambient radio environment and detection of its changes
  • Search for emission sources within selected frequency ranges, including frequency hopping signals
  • Plotting frequency-time diagram of loading within analyzed frequency ranges.
  • Automatic direction finding of radio emission sources with random modulation types and spectrum width in single-channel and multi-channel modes
  • Building of bearing panorama within operating frequency range
  • Real-time display of bearings, spectrum panorama, bearing history and signal amplitude history
  • Evaluation of signal parameters
  • Field strength evaluation
  • Recording of radio emission spectrum
  • Automated radio monitoring based on preset schedule or under operator control
  • Automated control of equipment health
  • Review and processing of the data from DB
  • Mapping DB information on the electronic map
  • Generation of reports with radio monitoring results in Microsoft Office, OpenOffice, HTML and PDF file formats.

In case of joint operation, the direction finders provides in addition:

  • Interaction via wire and wireless channels
  • Assigning tasks from master direction finder to slave ones, being operated within the same system
  • Transfer of radio monitoring data from slave direction finders to master one for further analysis and processing
  • Synchronous direction finding of radio signal sources
  • Transmitter location evaluation based on direction finding data (when ARC-GIS Geoinformational Server is included).

Basic Technical Specifications of Direction Finder in Complete Configuration

Operating frequency range 1.5 – 8000 MHz
Single-channel dynamic range (with attenuators) 110 dB, min
Intermodulation free dynamic range (3rd and 2nd order) 75 dB, min
Attenuators 0 - 30 dB with 2 dB increment
Max. processing bandwidth:
within 1.5-5 MHz range 1 MHz
within 5-25 MHz range 2 MHz
within 25-110 MHz range 5 MHz
within 110-220 MHz range 10 MHz
within 220-8000 MHz range 24 MHz
Panoramic Spectrum Analysis
Maximum simultaneous bandwidth 24 MHz
Panoramic spectrum analysis rate up to 20 GHz/s
Detected signal minimum duration 1 s
Single-Channel and Multi-Channel Direction Finding
DF method Correlative interferometer
Operating azimuth range 0° - 360°
Processed emitter signal spectrum width Arbitrary
Maximum simultaneous DF bandwidth 24 MHz
Multi-channel direction finding rate:
within 1.5-20 MHz range up to 10 MHz/s
within 20-8000 MHz range up to 2 500 MHz/s
Single-channel direction finding rate more than 100 bearing/s
Processed single signal minimum duration 10 ms
DF field sensitivity, max.
within 1.5-20 MHz range 15 V/m (typical 10 V/m)
within 20-3000 MHz range 6 V/m (typical 2 V/m)
within 3000-8000 MHz range 15 V/m (typical 10 V/m)
Instrument DF accuracy (RMS), max.
within 1.5-20 MHz range 5
within 20-3000 MHz range 2
within 3000-8000 MHz range 3
Radio Channel Monitoring, Technical Analysis and Broadcast Recording
Types of recorded data Bearing, demodulated signals, spectrograms, time, time-based signal sampling (I/Q)
Max. recording bandwidth 40 MHz
Continuous recording time Depends on the storage volume
General Parameters
Dimensions of antenna system (diameter x height) 2110 x 2820 mm
Dimensions of A/D Processing Unit 462 x 141 x 266 mm
Antenna System weight, max. 40 kg
Weight of A/D Processing Unit, max. 5 kg
Operating temperature range -55C +55C

Typical curve of RMS vs. frequency (MHz)

Typical curve of DF sensitivity (V/m) vs. frequency (MHz)

Fixed Means