JRC - JLR21-31 GPS Compass

The JLR-21/31 GPS compass continues the success of its predecessor, reaching a new level of performance and stability with many new features and enhancements. This system is also known as a 3D Dynamic Sensor™, which besides giving heading information, is designed to provide highly accurate information of the ships movement in all axis.

Heave compensation
The JLR-21/31 has heave functionality built-in as standard. In rough ocean conditions (with high waves), the GPS compass can correct up and down (attitude), movement. This is especially useful for fish finders and sonars on fishing vessels where high waves are compensated for with up to 20 cm accuracy, providing better potential for a profitable catch.

High speed update
JLR-21/31 supports Speed Over Ground (SOG) and Course Over Ground (COG). The position, SOG and COG are updated every 200 milliseconds (which is 5 times faster than previous model JLR-20), delivering high accuracy.

High speed tracking
The GPS compass has its origins as a direction sensing system, but the JLR-21/31 goes far beyond that. The JLR-21 provides heading accuracy of 0.5° and the JLR-31 has an impressive 0.25° heading accuracy. Heave accuracy is 20 cm or better and roll and pitch for both models is 0.5°. The tracking Rate of Turn (ROT) is 45° per second. On the left a comparison between previous GPS compass model (JLR-20/30) and the new model (JLR-21/31).


Display modes
The JLR-21/31 incorporates many display modes readily available on a highly visible 5.7 inch LCD display. The display is fully dimmable and the keys are also backlit, making it easy to operate in low-light settings on the bridge.

Simple operation
The compact design of the JLR-21/31 incorporates an intuitive interface, providing enhanced ergonomics and user friendliness. The logic of the controls and excellent on-screen menus will greatly shorten most users’ learning period.

Antenna design
The processor is built into the antenna. Eliminating alignment between antenna and processor found in separate systems, therefore contributing to an easy setup with less error and significantly reduced installation time. This concept also reduces the installation costs as only a single cable is used between antenna and display unit. The outer shell of JRC’s new antenna system has a smooth surface. This slippery exterior makes it almost impossible for birds to perch on the domes or for the antennas to be completely covered in snow. Should something interfere with the coverage, JRC’s proven antenna design incorporates a layer of air that reduces possible blind spots, allowing for a more precise heading than conventional systems.

IMO compliant v v
Receiver type Multi channel all-in-view (12ch 1ch SBAS)
Frequency 1575.42MHz ± 1MHz (C/A code)
Direction accuracy 0.5° rms 0.25° rms
Display resolution 0.1º
Resolution output 0.1º or 0.01º (selectable)
Tracking Rate of Turn 45º/sec
Tracking acceleration 1G
Roll/pitch output -60º to 60º
Startup time less than 2 minutes (warm start fix)
DGPS input RTCM SC-104 version 2.0 (type 1, 2, 9, 16)
SBAS receiver Built-in (WAAS/EGNOS/MSAS)
RAIM function Built-in
Position accuracy 12m 2drms (C/A code, HDOP4, SA OFF)
6m 2drms when SBAS corrected
4m 2drms when DGPS corrected (when connected to beacon receiver)
Display 5.7-inch LCD, 320 by 240 pixels
Operating keys & backlight 12 keys, LED (display and backlight keys)
Dimmer levels 4 levels (bright, medium, dark, off)
Display modes Compass rose, bow heading, navigation, rate of turn (ROT), water/ground speed, trend graph, calculation, GPS status
Output ports 5 independent working NMEA0183 ports
Transmission speed 4800, 9600, 19200, 38400, 57600 bps
Output interval 20ms, 25ms, 50ms, 100ms, 200ms, 500ms, 1s, 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s
Sentence1 IEC61162/NSK (shared) 5 ports (AD10 output available: 2 of 5 ports)
Current data input 1 port (CUR, VBW)
Alarm contact signal 2 ports (alarm output), 1 port (ACK input)
LOG pulse 1 port (off, 200p/nm, 400p/nm)
Power 12V to 24 V DC (-10% to 30%)
Power consumption 12 W (including sensor), 6 W (excluding sensor)
Transmission speed 4800, 9600, 19200, 38400, 57600 bps
Ambient conditions -15° to 55°C (operating), -25° to 70°C (storage)
Waterproof PX4 (display), IPX6 (sensor)
  1. Selectable sentences depend on version. ATT and HVE sentence can be set from output cycles of 25ms, 100ms, 200ms, 1s, 2s only. Some combinations of output sentence, bit rates, and output intervals may not be possible.