Garmin GMR 404/406 Radar Pedestal GMR 404/406 Owner's Manual - Page 14

Basic Operation > Radar Page MARPA The Mini Automatic Radar Plotting Aid (MARPA) function helps with collision avoidance. MARPA can track up to 10 designated targets. Detailed information including bearing, range, course, speed, closest point of approach (CPA), and time to closest point of approach (TCPA) for each target is shown in the MARPA list. Note: MARPA requires the use of a heading sensor. The heading sensor must output the NMEA sentence HDM or HDG at format 0183, v2.30 or higher. The Gamin Marine Network was tested using the KVH® 1000 heading sensor using six second dampening. For each target, a number and Vector Line is shown with the symbol. The number is the MARPA list ID number. The Vector Line is a visual reference of the target's course and speed. To designate a MARPA target: 1. Use the ROCKER to move the pointer to the target location. 2. Press the Acquire Target soft key. While a target is being designated, a red box appears around the target. When MARPA begins tracking the target, the box is replaced with the appropriate symbol. MARPA relies on a Heading Sensor to provide accurate own vessel heading information. Accurate heading data enhances MARPA's performance. Each target being tracked by MARPA is represented by a symbol. The symbols indicate the current state of the target. Acquiring target Target is safe Target is dangerous Safe targets Acquiring target Dangerous target Lost target  GMR 404/406 Owner's Manual