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I've heard of farmers going so far as to make their own GPS guidance systems, enhanced before they were widely available and reasonably priced. I'm not sure how

I've heard of farmers going so far as to make their own GPS guidance systems, enhanced before they were widely available and reasonably priced. I'm not sure how accurate and repeatable they were. Going to any farm that's been around for 20+ years, you'd see so many custom solutions that are really functional. Farmer one-off solutions are kind of like homebrew Excel applications - they're infinitely customizable, the end user knows exactly how it should work and can reasonably make it happen, and it's a small fraction of the cost of a commercial/IT SOLUTION. It may not be as reliable, but it's good enough.

pmiller2 7y ago
Does civilian GPS have enough resolution to be useful in a tractor guidance system?
- RosanaAnaDana 7y ago
  RTK does. Also, fields are big and 'generally' there isn't much to hit out there. I think most new harvesters these days are self driving.
  - froindt 7y ago
    That's true, but if you're spraying a field and veer off by ~12", you're running over corn and killing your profit.
- froindt 7y ago
  I belive they were enhancing it with terrestrial base stations (Loran-C was mentioned in the discussion, which was 10+ years ago). John Deere has proprietary secret sauce and if I recall correctly, they can get sub 1" accuracy. That precision farming has enabled things like different amounts of fertilizer for different parts of the field, a substantial material savings and improvement for the environment.
  - bryik 7y ago
    u-blox's ZED-F9P chip is capable of 10 mm (0.39 inch) accuracy [0]. AFAIK, high accuracy requires being relatively close to a terrestrial correction station. Some states, such as Iowa, run a network of these stations and provide free access to the public [1]. 0 - https://www.sparkfun.com/products/15136 https://www.sparkfun.com/products/15136 1 - https://iowadot.gov/rtn/IaRTN-resources/About-the-IaRTN https://iowadot.gov/rtn/IaRTN-resources/About-the-IaRTN
    - froindt 7y ago
      I'm from Iowa but had no idea the DOT ran such a network! Thanks for sharing!
- GlenTheMachine 7y ago
  Not by itself, in most situations. Maybe if you're automating a combine, where you're doing repeating patterns in a big flat field with no obstacles and where 1 meter deviations from the desired trajectory isn't an issue (not an uncommon situation, but for a lot of use cases you really do care about that 1 meter deviation, e.g. for plowing or cultivating). Otherwise you have to augment, eg with relative GPS or machine vision.
bryik 7y ago
Trimble GPS receivers go for around $10k (USD) [0], so I'm not surprised farmers try to build their own devices. Here's one who built an RTK GPS system out of a Raspberry Pi (and various other parts) for £250: https://www.youtube.com/watch?v=Kwxpo04AC5Q https://www.youtube.com/watch?v=Kwxpo04AC5Q 0 - https://trimble-exchange.com/store/item/used-trimble-r10-gnss-receiver-for-land-survey-pre-owned/1303 https://trimble-exchange.com/store/item/used-trimble-r10-gns...

pmiller2 7y ago

Does civilian GPS have enough resolution to be useful in a tractor guidance system?

RosanaAnaDana 7y ago
RTK does. Also, fields are big and 'generally' there isn't much to hit out there. I think most new harvesters these days are self driving.
- froindt 7y ago
  That's true, but if you're spraying a field and veer off by ~12", you're running over corn and killing your profit.
froindt 7y ago
I belive they were enhancing it with terrestrial base stations (Loran-C was mentioned in the discussion, which was 10+ years ago). John Deere has proprietary secret sauce and if I recall correctly, they can get sub 1" accuracy. That precision farming has enabled things like different amounts of fertilizer for different parts of the field, a substantial material savings and improvement for the environment.
- bryik 7y ago
  u-blox's ZED-F9P chip is capable of 10 mm (0.39 inch) accuracy [0]. AFAIK, high accuracy requires being relatively close to a terrestrial correction station. Some states, such as Iowa, run a network of these stations and provide free access to the public [1]. 0 - https://www.sparkfun.com/products/15136 https://www.sparkfun.com/products/15136 1 - https://iowadot.gov/rtn/IaRTN-resources/About-the-IaRTN https://iowadot.gov/rtn/IaRTN-resources/About-the-IaRTN
  - froindt 7y ago
    I'm from Iowa but had no idea the DOT ran such a network! Thanks for sharing!
GlenTheMachine 7y ago
Not by itself, in most situations. Maybe if you're automating a combine, where you're doing repeating patterns in a big flat field with no obstacles and where 1 meter deviations from the desired trajectory isn't an issue (not an uncommon situation, but for a lot of use cases you really do care about that 1 meter deviation, e.g. for plowing or cultivating). Otherwise you have to augment, eg with relative GPS or machine vision.

bryik 7y ago

Trimble GPS receivers go for around $10k (USD) [0], so I'm not surprised farmers try to build their own devices. Here's one who built an RTK GPS system out of a Raspberry Pi (and various other parts) for £250: https://www.youtube.com/watch?v=Kwxpo04AC5Q https://www.youtube.com/watch?v=Kwxpo04AC5Q 0 - https://trimble-exchange.com/store/item/used-trimble-r10-gnss-receiver-for-land-survey-pre-owned/1303 https://trimble-exchange.com/store/item/used-trimble-r10-gns...