A new series of integrated eLoran/Chayka/GNSS receivers emphasize low-power requirements and small size for alternative positioning, navigation and timing (PNT) to reduce risks of GNSS denial.
Loradd++, from Netherlands-based firm Reelektronika, consists of a receiver board of 60 x 30 x 8 millimeters, consuming less than 500 milliwatts (3.3 volts) in continuous operation. The Loradd++ can be used with either E-field or H-field antennas, features dual serial interface for integrated systems, and is connectable to certain miniature GNSS receiver modules.
eLoran and Chayka are recognized as alternative PNT systems, but current receivers on the market are large in comparison to miniature GNSS devices. Chayka is a Russian terrestrial radio navigation system, similar to Loran-C. It operates on similar frequencies around 100 kHz, and uses the same techniques of comparing both the envelope and the signal phase to accurately determine location.
The first of a new series of receivers is Reelelektronika’s Loradd++/E, which is an integration of the Loradd++ with an E-field antenna housed in a small single radome that can be connected via a data cable (up to 150 meters) and a dongle to a USB port on a PC. The radome contains a u-blox M8T GNSS receiver with antenna and measures 135 millimeters in height and 85 millimeters in diameter. The Loradd++/E needs less than 700 milliwatts at 4-16 volts.
Reelektronika manufactures eLoran equipment for users, service providers and surveyors. The company developed the eDLoran system. eDLoran works with existing Loran transmitter stations and yields differential Loran position and navigation accuracies comparable to GPS; see the cover story of the July 2014 issue of GPS World. The system can thus be considered as a robust backup for GPS.