by Dom Wiseman

Marine technology is moving at a rapid pace in the affordable radar segment with Garmin releasing its new GMR Fantom radar, a 40W solid state, pulse compression, Doppler radar. A Doppler radar uses the Doppler Effect (change in frequency waves) to detect objects. Garmin calls it its MotionScope technology. This type of radar is often used in meteorology but it also has applications in several other areas including aviation and radiology.
The introduction of this technology for recreational use has significantly reduced the cost of fitting a radar system into your boat, making it affordable, even for smaller trailerable fishing boats. The Garmin GMR Fantom is available in two different sizes, the four-foot with 1.8 degrees of beam width and six-foot with 1.25 degrees of bandwidth using an open array operating system that sits on the roof and swings around sending out a signal.
Using pulse compression technology Garmin achieve a maximum distance of 72 nautical miles putting it on par with other similarly priced radars. It delivers high-resolution images by maximising energy of targets to supply better detection and identification. Pulse expansion then maximises the target size to reduce noise.
Radar units are generally used on large boats to avoid close contact with moving and static targets. It can also be used to monitor weather cells. Moving targets on the radar are displayed in easy to distinguish colours enabling the user to identify potential collisions or severe weather quickly and easily. Garmin has also invested time in building in a setting that enhances the display for birds. They do this by slowing down the sweep of the signal so it has maximum contact with small objects.
The GMR Fantom radar also uses a feature called Echo Trails that displays a fading trail on the screen that can help users see the direction of moving targets and threats. The trails are also corrected for the rotation of the boat when used with an autopilot or heading sensor connected to the Garmin network.
Garmin said the GMR was equally effective detecting objects up close, it will highlight objects as close as 6m to the boat. It is important to note that due to the curved surface of the earth, the higher your radar array, the better your long-range detection. Too high though and you compromise close range detection. The Garmin FMR Fantom unit can display both ranges simultaneously allowing both close target identification and longer range issues such as storm cells.
With a built in optimization of the image, noise is reduced and the display is automatically adjusted for surroundings, and current weather conditions. The Manual Automatic Radar Plotting Aid (MAPRA) allows for tracking of up to ten targets as long as they are within radar range. You have to first manually select the targets which are then tracked automatically displaying bearing and speed of the object you are tracking. The system will also sound an alarm if the object gets too close and a collision is imminent.
The new GMR Fantom series, which has a starting price of $10,999, is compatible with GPSMAP 7400 series, GPSMAP 8000 series, and the new GPSMAP 8400 series.