What can you use a GPS for on a homestead?

Discussion in 'Homesteading Questions' started by Ross, Nov 7, 2004.

  1. Ross

    Ross Moderator Staff Member Supporter

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    Title says it all, I'm thining you could measure fencelines very easily with one and therefore acreage, but also it should be able to line up a fence or orientate a new building square with existing ones...... right? Any recomendations for a brand of GPS? OK it'd be a serious toy but Christmas is coming.
     
  2. GREEN_ALIEN

    GREEN_ALIEN Sunny, Wet, Tornadoey SD!

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    The is a built in error... of about 3 meters.
     

  3. diane

    diane Well-Known Member

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    Ross, I was thinking fence myself ever since I saw how one worked. Seems to me if you made a mark at each corner you should be able to tell if you are straight. The one my son-in-law has allows up to 10 marks. He is a hunter and likes it because he never has to worry about getting lost and not finding his truck when he hunts in the big state forest areas.
     
  4. GREEN_ALIEN

    GREEN_ALIEN Sunny, Wet, Tornadoey SD!

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    LOL maybe I was not clear enough on the first try.

    DO NOT USE A GPS FOR FENCING!

    There is a built in inaccuracy to keep bad people form doing bad things... like missle control etc. If you try to use one to build a fence you will be all over the place.

    Simple test. Grab a GPS and head out to the pasture. Turn on and set a waypoint where you are standing. Move ten feet and read location.. 9/10 it will be the same reading. If for some reson it is not then move just 5 feet...lol. Any fence built using a GPS will zig zag all over the place.

    GA
     
  5. Brad

    Brad Active Member

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    That is not the case, actually.
    Selective availability (ie "inaccuracy to keep bad people form doing bad things") was discontinued several years ago.

    You are correct about the present day inaccuracies, though the inaccuracies are caused by other reasons. However we can look forward to some pretty wonderful new features in the next few years. As it is now, the signal from the satellites are very weak and subject to RF interference and errors caused by delay through the ionosphere. Current GPS tecnology uses two frequency bands called the L1 and the L2 that fall into the microwave portion of the radio spectrum. L1 is commonly referred to as the civilian signal and L2 serves the military primarily.

    Starting in 2005 GPS satellites will begin to broadcast new signals that will boost the robustness of services and fine tune postioning accuracy by eliminationg ionospheric errors. This will be done by adding another civilian signal to supplement the L1 band. By 2008, a further round of improved satellites will begin to emit even more signals in a third frequency. These new signals will be four times as powerful as today's
    signals and will work indoors.

    These extra signals will enable a receiver to calculate the transmission delay caused by the ionosphere by comparing the delay in the various signals and calculating a compensation for it's effects. This means a higher accuracy GPS is on the way. As far as uses per the questions at the beginning of this thread, GPS and map software will be in the near future an excellent way to set points or property corners so long as one corner is surveyed as a starting point. The straightness of the fence in between the points is still the fencemaker's responsibility, however. ;)
     
  6. CJ

    CJ Well-Known Member Supporter

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    Actually Brad, I think Green has the right of it. Before Selective Availability was removed, they were only accurate within something like 45 meters, now it's more like 6 meters....still a large margin for error if running a fenceline off of it.
     
  7. Ross

    Ross Moderator Staff Member Supporter

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    Well thats too bad. If they made fish finders with that kind of accuracy they'd be directing you to the marina diner eating fish sticks more often than not! Maybe in a few years then. Guess I'll have to keep thinking.
     
  8. joan from zone six

    joan from zone six Well-Known Member

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    crooked fences have a certain charm (at least, that's always been my excuse)
     
  9. Yankee1

    Yankee1 Well-Known Member

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    I fyou get a GPS what has WAAS you can get accurate to 3 feet circumference. I use an Etrex Vista.
     
  10. CJ

    CJ Well-Known Member Supporter

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    Waas is 3 METERS, not 3 feet. But yes it does improve it. But that's still too much for a fenceline :)
     
  11. Rowdy

    Rowdy Well-Known Member

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    Okay, it _is_ possible to clear a straight fenceline with gps (I have two straight ones to prove it.) The trick is to account for the possible error, and of course do not use the gps to mark actual fence posts.

    If you buy a GPS with waas it should be accurate to about 3 meters. This of course is if you have clear sky and good luck. Without the waas feature it is pretty hopeless, as that it could be almost 20 feet off. Though the unit I used was rarely more than four FEET off, with clear sky. I also would come back and take mulitple readings, using the average.

    I had 1250 feet of dense oak to clear for a fence/ property line. The corners were surveyed and marked. What i did was record each corner on the gps, then plotted a line three feet on my side of the property line. I wanted a road next to my fence line anyway, so even if the gps was wrong for three feet more, that would only be six feet total from the real property line. Even if I did end up that much off, I would still be close enough . I also got my neighbor to let me clear six feet on his side of the property line as well, so I had total of 12 feet of clearance.
    I then loaded my bag with stakes and marking tape and set out marking the fence line. I would go so far ahead, make sure I could see the last stake, get a reading, get on the line, mark the spot and move on. If the trees got in the way of the gps, I would eyeball the stakes I could see behind me, then use the chainsaw to get a clear view of the sky.

    Once the marking was done I climbed on the dozer and just grubbed a straight line following the stakes. Must have done something right though, since I started three feet to the west of the first corner and ended up about a foot west of the other corner. From there I grubbed out the full width of the right of way. When I wanted to mark the actual property line for the fence I rented a transit for $50 a day, set up on one of the corner benchmarks and shot a straight line to the other corner.

    Really, I could have done the clearing with a transit or a total station machine just a easily, but I had the loan of a gps to play with, so.....

    but of course your mileage may vary, and before cutting trees be _sure_ of which side of the property line the tree is on, or have a written agreement.

    Rowdy
     
  12. mikell

    mikell Well-Known Member

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  13. Windy in Kansas

    Windy in Kansas In Remembrance

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    Ross as a farmer you are probably familiar with other uses for GPS than has been mentioned here. Others may not, so I'll tell about some of them.

    GPS devices can be installed along with monitors on combines. Mapping is done in advance, and the combine records yield per grid. When a yield map is printed out it shows areas that may need more fertilizer. Soil tests are taken with GPS gridding. A fertilizer applicator can then cut back fertilizer in areas where not so much is needed, and load up other areas where it is. Overall saving the famer fertilizer dollars. Of course such systems are expensive and smaller farms cannot justify having them. Custom cutters and applicators may have them however.

    Remote control and robotic tractors are on the near horizon, and I expect that they will use GPS devices.

    I worked for a county weed department this summer. Often it was a real hassle for employees to coordinate with farmers as to when and where to spray fields for noxious weeds. One plant sprigg on a 160 field can be like a needle in a haystack. I foresee having units for the farmers to check out from the department. The farmers can then locate needed spray locations into the unit, check them back in, and the spraying can be done when convienent for the department, i.e. when in one area, thus saving running all over the county at the whim of when farmers can meet.

    I would also like a unit on the spray truck I run to enter locations I am spraying. I could then go back later to see that I hadn't missed any plants. Also the other department men could enter locations as they see plants, then I could spray them when in the area. You may ask why they wouldn't just spray them--well often we are carrying different chemicals for different weeds.

    The county received a $40,000 technology grant, already has a computer GPS mapping program, so I would like to see the department get three units for the trucks, and several cheaper and simplier units to loan to farmers for the aforementioned use. Sure hope that the director can get a small piece of the pie.

    Of course I like the idea of having a unit to check speedometers with on my own vehicles. My old 1949 truck doesn't have a working speedo, so a GPS unit could keep me from speeding.

    Expect some of you have also heard of "geo-caching". GPS devices are used to seek out treasure left by others. When you find it you take an item and leave another. What a great sport. The last time I went with a friend we watched soaring bald eagles in a river bottom. That alone was a treasure.

    Of course I want a unit, a good unit.
     
  14. Brad

    Brad Active Member

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    Hi CJ,

    When I wrote "As far as uses per the questions at the beginning of this thread, GPS and map software will be in the near future an excellent way to set points or property corners so long as one corner is surveyed as a starting point.", I meant that in the near future this will be a viable option for fence running, as opposed to at present it not being. Sorry I was not clearer on this.
     
  15. uncle Will in In.

    uncle Will in In. Well-Known Member Supporter

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    One of the uses farmers have for GPS is in combines and fertilizer spreaders. My renter has a yeild moniter in his combine that gives an on going digital reading of the yield in bushels per acre of the crop as it goes through the combine. This is fed into an on board computer that is also connected to the GPS moniter. The computer has maps of the fields and posts the yield on the maps where the GPS system tells it the combine is located. After harvest the software goes to the fertilizer company who has large field spreaders. The spreaders also have the same set up and the rate of application of the fertilizer is controlled automaticly by the yield shown on the software. The areas that have the lower yields get more fertilizer per acre.

    It costs the renter $25 per acre to have this service. He told me he sometimes feels he would be money ahead if he spent the $25 on fertilizer and just gave it all a little heavier application.
     
  16. mary,tx

    mary,tx Well-Known Member Supporter

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    It seems to me that the question was in regard to homesteading and not large-scale farming (combines, large-scale spraying, etc.). :rolleyes:

    From what has been written, most indicated that GPS would not be very useful for fencing, but the way I see, it is quite useful in that I often leave my tools laying around where I was last working. Though I plan on returning soon, I sometimes get distracted by other things. If I were to record the location where I last left my tools, I could save a lot of time searching because I could easily get back to where I left them. So what if I am off by a few feet, my eyes could make up the difference. :haha:

    Seriously, the common inexpensive GPS units (non-survey grade) would not have the accuracy for fencing, though if you left a unit in one place for a long period of time (perhaps from a few minutes to several hours depending on the accuracy desired) and recorded the readings and averaging the numerous position results over time you could get a fairly accurate approximation of the location of various points.

    For example, if you wanted to map something on your homestead, you could do so, but it would take some amount of time for each point depending on the accuracy you desired. Another example would be to see how far it is from your house to your picnic area or barn, or whatever to determine how much line you would need for power and water lines, etc. You could also determine how long your road is to order materials such as gravel/paving, etc. or plot the location for power poles knowing the maximum spacing. Another example is to determine the size of each garden/pasture/padlock/field, etc. as if it mattered. (Perhaps to calculate the number of fire ant mounds per acre? :haha: )

    If you want to map a location and don't need high accuracy (for example, a septic system that needs a 100 foot setback from creeks, well, etc.), you can use GPS and simply add in a margin of safety if spacing is not too tight.

    If you have a large peice of property, another use is to get the coordinates for all corners of your property. You can then "google" for satellite image web sites and purchase a satellite image of your homestead using the coordinates. (I saw one that had almost 0.6 meter resolution.) Of course, you can search by street address, but that would not get you the property boundries for ordering the color glossy image. (Note, I did notice one site that would display the coordinates of where the mouse cursor was pointing on the image, but that takes the fun out of it.)

    Dale (dh of mary, tx)
     
  17. blanknoone

    blanknoone Member

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    Sell it and buy something really useful with the money?

    Sorry, philisophical difference. I don't think it wise to buy gadgets then try to figure our something useful with them. I find that if I think carefully about it, there are a million things I would love to spend money and effort on to improve the place. Even if I had one, (and I used them extensively in the military, and have also used them to check myself when hunting in unfamiliar parts), my time would be better spent doing somthing that needed doing rather than figuring out some way to use it.

    Now that I said my piece, I don't have much constructive to offer. I hope you find some useful advice and thoroughly enjoy your GPS.
     
  18. Ross

    Ross Moderator Staff Member Supporter

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    Well I don't own a combine and wouldn't have a lightbar on it anyhow Unk. My neighbor has the GPS equip but doesn't use it (came on the combine) he figures it might help resale value. I've seen the field mapping and if you combine it with spray application as well as fertilizer over a few thousand acres it might save some money but it looks a bit much for anything less. Still I know a fellow who uses it on his 100 acres of crops. Nutz if you ask me.
     
  19. ponyboy

    ponyboy New Member

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  20. retired03

    retired03 Member

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    I have an eTrex and found that where you are can have a large effect on the accuracy according to the GPS.

    Here in Michigan when I use it I am usually lucky if I can get and accuracy listed as 45 feet (15 meters). But when I was in northern Georgia on the Appalachian Trail in the mountain valleys where I thought I would be lucky to get a signal the GPS said I had a less than 3 meter accuacy (6 feet).

    Food for thought.