Some Topcon questions,

[GolfGPSSprayer]

I’m the spray tech/assistant superintendent at a golf course in the US. My superintendent is a bit of an early adopter/innovator. Between him and an owner of another local course, they’ve been utilizing agriculture tech for custom builds/retrofits on golf course equipment for some years now, well before Toro or Deere have entered the GPS game.

Since it’s a one-off build with unfamiliar tech, the questions I’ve been accumulating over the past year aren’t readily answerable and/or aren’t issues that come up using the tech as intended in large fields with little to no obstacles.

1) While making apps, I will sometimes be making a pass and go through an area with a tree that disrupts the GPS signal/lose RTK. Most of the time it will just change to estimate, but sometimes it will bug out between estimate, GPS, and no signal; and when that happens, it will put my vehicle hundreds of yards away and map coverage in between where I am and where the GPS thinks I am. I’ve attached an example of what I mean.

Is there anyway to alter settings to a) prevent this, or b) undo/delete that portion of the job, without clearing the entire job coverage data?

2) Is there a way to combine fields?
i.e. when I want to spray just our rough grass, could I combine the fields I’ve mapped for our greens, fairways, and tee areas without having to remap our entire course?

Thanks in advance!

 

[Pheasant Surprise]

I guess the first thing is to say, trees and receivers generally don’t make for happy marriage. You will always being in dropout territory whilst the antenna is obscured, even partially. On screen it says that your tracking 7 satellites, which (if GLO is switched on) is not great. You’d really want to see that many from each constellation, so a good 14 or so from GPS+GLO and way more if you were using more modern constellations like GAL and/or BeiDou (compass).

Worse too if your correction signal is also coming via satellite (as opposed to radio or mobile/cell service). It’s easy to lose that one satellite over the equator under trees, especially if your sufficiently north (or south). What are you using for correction?

What Topcon receiver(s) are you using on your gear?

 

[GolfGPSSprayer]

I guess the first thing is to say, trees and receivers generally don’t make for happy marriage. You will always being in dropout territory whilst the antenna is obscured, even partially. On screen it says that your tracking 7 satellites, which (if GLO is switched on) is not great. You’d really want to see that many from each constellation, so a good 14 or so from GPS+GLO and way more if you were using more modern constellations like GAL and/or BeiDou (compass).

Worse too if your correction signal is also coming via satellite (as opposed to radio or mobile/cell service). It’s easy to lose that one satellite over the equator under trees, especially if your sufficiently north (or south). What are you using for correction?

What Topcon receiver(s) are you using on your gear?

I’m in southeast Michigan, so not super far north.

We have a AGI-4 roof mounted on the sprayer, and we use a base station (not sure which model at the moment) on a ground tripod. We do use GPS+GLO, no cell or radio. I know it said 7 on that screen, but I was parked in a non working area while I typed out my post. Usually if I’m in clear areas, I’m locked in to 12-14 satellites, and obviously less when obstructed.

Forgive me for not being well versed, but in settings it says our correction source is RTK, GLONASS is enabled, Trupass is disabled(&unavailable), RTK protocol is CMR, and fallback is disabled.

 

[Pheasant Surprise]

First thing I’d do is enable fallback (to WAAS, we know it as EGNOS here, same thing basically), it may help if you lose correction, although a tripod and working nearby you should be OK. Ensure the tripod also has a nice clear sky view.

If it’s a Topcon base (Tripod) it really should be using RTCM3 correction rather than CMR, as you may only be getting correction on GPS sats rather than both GPS & GLO. You really want both, you won’t be getting the benefit of seeing the GLO birds if your not also receiving a GLO correction from the base.

I think your main issue is simply loss of (sufficient) main satellites under foliage.

 

[Robt]

Sorry to disagree with @Pheasant Surprise but don’t enable fall back. If you are constantly losing your RTK due to reduced sat numbers. Fallback will make map shift worse. Fallback is designed for auto steer not mapping
Edit, you will get glonass using CMR although RTCM3.x is a better option. Both support Glonass

 

[Northern farmer]

What does "We do use GPS+GLO, no cell or radio " mean? If you are using a tripod, most often you would be using radio for RTK correction signal transmission.

Robt should know and still remember Topcon stuff well but how come fallback would be better for autosteer than mapping and how come the error would be worse with WAAS fall back rather than autonomous GPS+GLONASS?

Honestly I'm not really familiar with fall back because we hardly lose RTK fix but I wonder how AGI-4 makes use of the gyros, is it really only used for tilt compensation (in all axes)? I could imagine the gyros only handling pretty perfectly the short term loss of RTK fix under trees. Think of a car navi in a tunnel, orders of magnitude better accuracy compared to the example photos above.