Garmin GPSMap - Custom settings reset after reboot

[Skybolt]

The triangle (AIS) is just right of the radar target (blue target).

I can't tell from the pic, but do you have your gps compass set to true instead of magnetic? If it is set to true, that will do what you are seeing. I had to switch everything to mag and now they are pretty close. There is also an alignment procedure for the radar return to the chart. Either one could be the cause. If trying to align the radar to the chart, do not use buoy's, use the land mass to check.

When doing the radar alignment it is a bit of a trade off to get it right, it may still be slightly off. Most of my returns are like a close shadow.

EDIT: https://support.garmin.com/en-US/?faq=YfbZHr8eHm7bUQ7isJOix9

Also:
1. From a Radar screen or the Radar overlay, select Menu >Radar Setup > Installation > Front of Boat.
2. Select Up or Down to adjust the offset.

I believe that is the degree or offset adjustment.

 

[Irie308]

I can't tell from the pic, but do you have your gps compass set to true instead of magnetic? If it is set to true, that will do what you are seeing. I had to switch everything to mag and now they are pretty close. There is also an alignment procedure for the radar return to the chart. Either one could be the cause. If trying to align the radar to the chart, do not use buoy's, use the land mass to check.

When doing the radar alignment it is a bit of a trade off to get it right, it may still be slightly off. Most of my returns are like a close shadow.

EDIT: https://support.garmin.com/en-US/?faq=YfbZHr8eHm7bUQ7isJOix9

Also:
1. From a Radar screen or the Radar overlay, select Menu >Radar Setup > Installation > Front of Boat.
2. Select Up or Down to adjust the offset.

I believe that is the degree or offset adjustment.

Will give it a try.

 

[ttmott]

The triangle (AIS) is just right of the radar target (blue target).

I don't know Al @alnav , if you look at the rings he is at 1nm so the targets are distanced just about a mile between each other.
I'd like to attribute it to latency, calibration and alignment but you could almost draw a straight line from the boat through both the MARPA and AIS targets. Quite possibly the other boat's AIS GPS coordinates are in error but still that straight line. The only thing I can think of is do a ranging test on the radar.

 

[alnav]

I don't know Al @alnav , if you look at the rings he is at 1nm so the targets are distanced just about a mile between each other.
I'd like to attribute it to latency, calibration and alignment but you could almost draw a straight line from the boat through both the MARPA and AIS targets. Quite possibly the other boat's AIS GPS coordinates are in error but still that straight line. The only thing I can think of is do a ranging test on the radar.

Agree it could be several things. For Erie, even if you don't commonly use it, you might want to turn on a radar overlay while underway and near land, preferably land with some sharp features. That will quickly reveal if you have a bearing or range difference (or both).

 

[Irie308]

Ok, I’ve found a better photo. Fog was very dense that day and had quite a few more targets running AIS. You can clearly see how they all don’t line up.

EDIT: Pay no mind to my route line as I’m purposely not following my route as it would have brought me on top of that vessel.

 

[Irie308]

Agree it could be several things. For Erie, even if you don't commonly use it, you might want to turn on a radar overlay while underway and near land, preferably land with some sharp features. That will quickly reveal if you have a bearing or range difference (or both).

Was thinking of doing that based on your previous post.

 

[ttmott]

Not trying to be cheeky but are you sure the AIS target isn't obscured under the MARPA target? The reason I say that is it seems the radar is painting all of those distant AIS targets also.

 

[Irie308]

Not trying to be cheeky but are you sure the AIS target isn't obscured under the MARPA target? The reason I say that is it seems the radar is painting all of those distant AIS targets also.

Edited as I’m not sure I understand. See my most recent photo for better example of issue. Last weekend I ran about 30 mins in the dark. There were two tugs. One pushing a large barge the other towing a large barge. This was when it became apparent that this could be borderline dangerous as I wasn’t certain what ais was saying vs what the radar was painting. I ended up turning off my ais and relying solely on the radar.

 

[ttmott]

Edited as I’m not sure I understand. See my most recent photo for better example of issue. Last weekend I ran about 30 mins in the dark. There were two tugs. One pushing a large barge the other towing a large barge. This was when it became apparent that this could be borderline dangerous as I wasn’t certain what ais was saying vs what the radar was painting. I ended up turning off my ais and relying solely on the radar.

I apologize. I had thought the AIS target you ID'd in green lettering was a MARPA ID. When I zoomed in on the pic it was an AIS target that was ID'd. What you are saying is the radar painting of a target is not in the same location as the AIS location. The targets behind the boat are to the left of the AIS and in front on the right. This appears to me the adjustment that @SKybolt references to set the front of the boat in the installation settings.

 

[Skybolt]

Ok, I’ve found a better photo. Fog was very dense that day and had quite a few more targets running AIS. You can clearly see how they all don’t line up.

EDIT: Pay no mind to my route line as I’m purposely not following my route as it would have brought me on top of that vessel.

Looking at this pic, it looks like your gain is up too high. Unless it was a rough night? All of those little blue blobs can't be boats, so that must be waves? If you turn down the wave clutter your image would clean up a lot. Was this in open water?

 

[Irie308]

I apologize. I had thought the AIS target you ID'd in green lettering was a MARPA ID. When I zoomed in on the pic it was an AIS target that was ID'd. What you are saying is the radar painting of a target is not in the same location as the AIS location. The targets behind the boat are to the left of the AIS and in front on the right. This appears to me the adjustment that @SKybolt references to set the front of the boat in the installation settings.

Yes, will try those setting changes.

 

[Irie308]

Looking at this pic, it looks like your gain is up too high. Unless it was a rough night? All of those little blue blobs can't be boats, so that must be waves? If you turn down the wave clutter your image would clean up a lot. Was this in open water?

Agreed, i think the gain was a bit high. It was more apparent when I enabled the echo trails.

 

[alnav]

Irie, I think there's another clue in your second radar screen shot. I noticed your GPS COG is 317° while your internal compass heading is 314°. It's possible you were being set a bit but in perfect conditions the two readings ought to match. If your radar display were to rotate 3° clockwise I think the radar and AIS targets would either merge or at least be a lot closer.

 

[Irie308]

Irie, I think there's another clue in your second radar screen shot. I noticed your GPS COG is 317° while your internal compass heading is 314°. It's possible you were being set a bit but in perfect conditions the two readings ought to match. If your radar display were to rotate 3° clockwise I think the radar and AID targets would either merge or at least be a lot closer.

Noted, will add to list of things to try. Thanks!

 

[Skybolt]

Noted, will add to list of things to try. Thanks!

I believe you have two things going.

1. The AP heading sensor and GPS are not aligned and off a few degrees as @alnav Al indicates.
2. The Radar possibly needs to rotate CC to try and align the AIS with the returns. Not sure which bearing the radar is using to display the returns.

Do those in that order and check in between setting(s). But if the COG and Heading match, then the bow of the boat can be aligned properly in the radar setup screen.

Too many alignments in play here. You would think the bow of the boat would be the first thing to align, but you need accurate compass and heading sensor alignment(s) to do that.