Northstar M121 Radar Chart Overlay

[adriano]

Hi all,

I have a M121 with a 4Kw HD Radar and a Heading Sensor. I also have other components installed in this unit. I am very happy with the unit. I have just noticed that the Radar Chart overlay does not line up correctly on charts objects when I am in close. Say that I am 200 yards away from a beacon, the radar image is not aligned well with the beacon on the chart. Let's say that it is 100 yards off. How do I adjust this? If I navigate to an object dead on, the image is spot on in the middle, so I am not keen on adjust the zero bearing. Also it does not seem to be just off in bearing degrees but also in distance. Do I need to to do a Chart data offset? If I navigate just based on the Chart image the position of the boat seems pretty accurate so I am tending not to use this option.

Any feedback would be appreciated,
Adri

[HighMark]

In the installation manual. it talks about this. And what to do to correct for it.
it's an over lay adjustment. it was easy to correct for. I do not have the book
in front of me . but Just follow the directions.

[adriano]

Hi Mark,

And thank you for your feedback. From the standard manual, I think that the feature you are referring to is the Zero Bearing. Reading through the instructions on this feature, it sounds to me as you can simply rotate the image in 1 degree increments. As I was driving through a channel, my impression was that the boundaries of the radar where closer than the ones of the chart. I almost got the impression that I needed to adjust the distance rather than the bearing. Does that make sense? Do you understand what I mean?

I have just setup the Radar and tested it for the first time. I might retry having a good look and see if I can achieve the desired result with a combination of

1) Map Shift
2) Zero Bearing

It might be that even though the boat seems positioned quite accurately on the chart with a small variation there plus a small zero bearing adjustment, I might achieve the desired result.

I will also re-check the installation manual and I will keep you posted,
Adri

[Chass]

Hello Adriano,
Which Radar model # antennae you using?
Thanks,
Chuck

[adriano]

Antenna is NS-RDR1042MD Unit: NKE-249
4KW Processor is AA010013 with software SW REV 1.6.170

I originally had bought a different 4KW Processor box, NS004781R also with software SW 1.6.170, but I was never able to get this to work. After I replaced it for the AA010013 it has been working like a dream.

Adri