Radar and heading sensor for overlay

C

C-Dawg

New member
For those that have put radar on the boat, did you include a heading sensor so you have radar overlay on the chartplotter? Or are you comfortable with viewing two screens side by side--the radar and the chart?

I have a Furuno 10" multifunction chartplotter and I'm getting ready to order the radome. It's another $670 for the heading sensor, but that allows me to overlay the radar output over the chartplotter display. Just not sure if it's worth it or not.

What say you?
 
I for one really love the over lay feature on my c-80. It allows you to see if the blue blob is something that is suppose to be there or not. And having all the info on one screen frees up screen space for the depth sounder. I really cant think of why you would not want overlay. As far as redundancy, I would have two units capable of over lay. I also like the ability to track targets in relationship to myself. The c-80 sill track up to ten targets at once. This last summer I set my screen with three screens. One in the depth finder, never run with out it. The other two screens are maps with radar over lay. One set at half a mile and the other at 4 miles or more. This saves me from zooming in and out all the time. I will have the saved course and way points displayed on the 4 mile plus screen and just the map and radar on the other. If the fog gets real tight and vis is down to a few hundred feet i will still run both screens but I will adjust the radar for better signal at close range. better to see what it going to hit you first. I have seen kayaks on the screen before seeing them out the window. It only takes once in the fog with out radar to convince you that you need it.
 
I'm with my buddy Tom on this: the radar is even easier to interpret when overlaid on the chartplotter. :thup Same with dividing the screen in low vis.

Best wishes,
Jim B.
 
Are you sure that you need a heading sensor to get radar overlayed on the chart?

My older Raymarine unit specifies that a heading sensor is needed to have overlay in all modes. But, I get fully synchronized radar overlay without a heading sensor. The GPS is sufficient to get overlay on my unit.

By not having a heading sensor, I have to use "Course Up" or "North Up" to get overlay. I can't use "Heading Up". But, it's not a problem. I can still get fully synchronized radar overlay without a heading sensor.

It's worth asking Furuno if you will get overlay in some modes without the sensor. Or just get the dome, and see if overlay works without a sensor, and add a sensor if needed.

By the way, I find that radar is only useful if it is overlayed, as I'm not fluent in reading radar.

Rick from Maine
 
I have the radar overlay on the C80 and I wouldn't have it any other way. This was my first boat with radar and the overlay really helps with the learning curve. I always run my radar, even when it's clear, so I'm familiar with it when the conditions get bad. In clear conditions I run with the chart taking up the full screen and the radar overlaid on top. In poor visibility I split the screen, one with the chart and overlay and the other just with the radar.

I'm not sure if the C series overlay works without a heading sensor. I opted to get the KVH Azimuth 1000 digital compass which feeds data to the C80 through NMEA 0183. This route costs significantly less than the Raymarine (or Furuno) heading sensor and works just fine.
 
If what you are calling a heading sensor is the same as my fluxgate Azimuth 1000 then you probably should have one. The problem with not having one is that your GPS and your radar are both updating their respective signals using much different timing. The difference in that timing will not give you an accurate overlay and will be offset from each other to one degree or another.
 
The Garmin 4210 will provide radar overlay without a heading sensor. The heading sensor adds collision avoidance capacity to the RADAR function of the 4210. Since the heading sensor provides a constant heading to the GPS/RADAR (even if anchored or underway but not making way) directionally consistent targeting information is always available. This means the Captain can use RADAR to track the potential for collision in low visibility even if SOG=0, and know from which magnetic and relative direction the threat will approach.
Mike "Levity"
 
I don't use overlay, and use separate radar and chart plotter, doing the "overlay" in my mind (comes from doing this over paper charts, plotting boards etc)--

To have an accurate heading sensor, you need a gyro rated compass--the standard flux gate and gPS are not fast enough or accurate enough for most overlays--and that is why the heading sensor is more expensive. Many auto pilots use the gyro rated compass, and that same compass can suffice. Again--to get the most accurate picture at high speeds, with changing courses. If you are going slow on a constant course, you may get adequate overlay with a less expensive sensor, but I would pay the $$ and get the correct unit.
 
Raymarine and Garmin use the GPS heading to do the overlay. WOrks ok, unless the boat isn't moving.

Furuno requires a heading sensor for the overlay function. They want tru boat heading at all times.

So, yes, I've done it on a number of furuno packages, and their heading sensor is really very good, and easy to install. Plug and play with a simple initial set up.
 
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