Technology

Technology

LOCATE provides a combination of wideband and narrowband data to deliver a comprehensive HF monitoring package.

The wideband data provides a valuable snapshot of the full HF spectrum so that energy can be detected. The streaming narrowband data is used to receive individual frequency channels which can be demodulated and analysed. Monitoring of the spectrum, frequency selection and control are all easily managed by a Windows® graphical interface.

Super-resolution Direction Finding (SRDF)

LOCATE employs advanced SRDF techniques to enable the simultaneous estimation of directions of arrival for co-channel signals. Additional operational advantages of SRDF include:

  • An order of magnitude increase in spatial resolution
  • Increased Direction Finding (DF) accuracy
  • Simultaneous azimuth and elevation DF
  • Operation with short duration signals
  • No requirement for a particular array geometry

Adaptive Digital Beamforming (ADBF)

The capabilities of LOCATE are further enhanced by the inclusion of ADBF. The enhanced output from ADBF (E-Copy) allows a Signal of Interest (SOI) to be detected and demodulated regardless of the presence of other signals. Advantages of ADBF over single antenna reception include:

  • For an N antenna array, a signal to noise improvement of up to 10log(N)dB
  • Signal to interference improvement of up to 40 dB, when in the presence of strong interference
  • Discrimination between signal propagation via groundwave and multiple skywave modes

Geolocation

The geographical position of a transmitter can be determined by LOCATE using both single or multiple arrays. For a single array system the location is estimated using DF results in conjunction with measurements or modelling of the ionosphere. More accurate position fixes can be achieved using triangulation techniques on DF results from multiple arrays.

LOCATE systems can be networked using TCP/IP, and DF data is managed and a position calculated with the Geolocation Manager software. If required, the DF data from non-LOCATE sites can also be incorporated into the position solution.