Anyone use GPS app for spraying/planting/spreading?

   / Anyone use GPS app for spraying/planting/spreading? #1  

mjw357

Platinum Member
Joined
Jan 30, 2011
Messages
698
Location
The Sticks, Ohio
Tractor
Kubota B3200
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?
 
   / Anyone use GPS app for spraying/planting/spreading? #4  

Skagit

Silver Member
Joined
Jun 22, 2020
Messages
103
Location
Washington
Tractor
Massey Ferguson 184-4
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.
 
   / Anyone use GPS app for spraying/planting/spreading? #5  

JCoastie

Gold Member
Joined
Aug 29, 2020
Messages
430
Location
Coastal AL
Tractor
LS MT240HE
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"
 
Last edited:
   / Anyone use GPS app for spraying/planting/spreading? #6  

Skagit

Silver Member
Joined
Jun 22, 2020
Messages
103
Location
Washington
Tractor
Massey Ferguson 184-4
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
 
   / Anyone use GPS app for spraying/planting/spreading? #7  

Skagit

Silver Member
Joined
Jun 22, 2020
Messages
103
Location
Washington
Tractor
Massey Ferguson 184-4
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
 
   / Anyone use GPS app for spraying/planting/spreading? #8  

bdog

Elite Member
Joined
Mar 26, 2004
Messages
2,632
Location
Texas
Tractor
Kioti RX 7320
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.
 
   / Anyone use GPS app for spraying/planting/spreading? #9  

s219

Super Member
Joined
Dec 7, 2011
Messages
8,604
Location
Virginia USA
Tractor
Kubota L3200, Deere X380, Kubota RTV-X
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.
 
   / Anyone use GPS app for spraying/planting/spreading? #10  

MHarryE

Elite Member
Joined
Feb 15, 2009
Messages
2,857
Location
Northeastern Minnesota
Tractor
Kubota M7-171, M5-111, SVL75-2, RTV900XT & GR2120; CaseIH 1680 combine
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.
 
 
Top