Anyone use GPS app for spraying/planting/spreading?

[mjw357]

Looking for a simple GPS app for smartphone or tablet that allows you to set a swath, then records your path around the field so you can keep track of where you’ve been. Suggestions?

 

[hosspuller]

I'm a terrible driver. I leave strips of missed areas. I bought this ... onTrak Agricultural GPS System with simple app control - Agricision Ltd

 

[grsthegreat]

Even a real gps unit can be 20 feet off on accuracy. How good can an ap be

 

[Skagit]

Even a real gps unit can be 20 feet off on accuracy. How good can an ap be

If your GPS unit is off 20 ft that's because it's using the same location technology as your cell phone. A 'real' GPS unit is accurate to about 6 inches or even less (1-2") if you have a base tower setup.

That said, I've sprayed with a cell phone app. It's better than nothing but that's also with a 60 ft boom, if you've got one of those tow behind 7 ft sprayers it's completely useless. Just put dye in the tank.

 

[JCoastie]

If your GPS unit is off 20 ft that's because it's using the same location technology as your cell phone. A 'real' GPS unit is accurate to about 6 inches or even less (1-2") if you have a base tower setup.

No, it isn't, not at a civilian consumer level...period. And GPS repeatability is even worse. I have a background in both differential GPS site and LORAN station maintenance. Unless you are averaging multiple high sample rate multi antenna sources, (not satellites, but receiver sources) you aren't even close to 2", on good occasion 2' can be achieved, but not 2". Many times the space signal can be off more than 2' before you even begin processing it which degrades it further, not improves it.
One of the reasons the FAA does not consider GPS as a 'precision approach"

 

[Skagit]

No, it isn't, not at a civilian consumer level...period. And GPS repeatability is even worse. I have a background in both differential GPS site and LORAN station maintenance. Unless you are averaging multiple high sample rate multi antenna sources, (not satellites, but receiver sources) you aren't even close to 2", on good occasion 2' can be achieved, but not 2". Many times the space signal can be off more than 2' before you even begin processing it which degrades it further, not improves it.
One of the reasons the FAA does not consider GPS as a 'precision approach"

So, ok... You didn't read my post and I'm guessing you have no experience in commercial agriculture. We're not talking about flying airplanes here, this is setting a straight line for field work to reduce crop loss caused by overlap or misses during spraying or cultivation. If you read the last part of my post I referenced using base towers to achieve 2" accuracy levels, that's a ground based tower system such as John Deere RTK, without that you're 6"+ using a stand alone GPS system.

Here's some reading material if you're interested www.deere.com › brochurePDF
John Deere Guidance Systems

 

[Skagit]

So, ok... You didn't read my post and I'm guessing you have no experience in commercial agriculture. We're not talking about flying airplanes here, this is setting a straight line for field work to reduce crop loss caused by overlap or misses during spraying or cultivation. If you read the last part of my post I referenced using base towers to achieve 2" accuracy levels, that's a ground based tower system such as John Deere RTK, without that you're 6"+ using a stand alone GPS system.

Here's some reading material if you're interested www.deere.com › brochurePDF
John Deere Guidance Systems

Edit: Here's the link that works Guidance | Mobile RTK | John Deere US

 

[bdog]

I work with Trimble RTK equipment. Sub inch on the horizontal is easily doable. This is not consumer grade stuff though. I do also use garmin GNSS units and the vast majority of the time they are within 5’ of true location. We have cut thousands of miles of right of way using garmins and then come back with the RTK. It matches up surprisingly well.

Still as mentioned if you have a narrowish boom the error may be approaching the width of your boom.

 

[s219]

Cell phones are good to about 3m (~10 feet) nowadays, but usually do slightly better under good conditions.

I have a sub-meter system for surveying that is considerably more complicated and much slower. But if you have time and want to setup the equipment, then wait for it to converge, it can give about 8" accuracy. Not something I'd want to use on a tractor though, or when any sort of movement is involved. You'd be moving faster than the system can react and converge.

I really like the systems with a fixed base station and then use differentials to work out relative position. Those can be super accurate. But cost and complexity go up.

 

[MHarryE]

I have a New Holland EZ Guide 250 unit which is really a Trimble packaged with New Holland logo. It’s advertised with correction service to give 6” to 8” pass to pass accuracy. Works fine for me for spraying and fertilizer spreading but it’s not accurate enough for planting. Much of my farmland is so crooked - no straight edge on some fields - that I haven’t considered the auto steer option.