any SmartPhone (android) GPS apps with better that 1 degree horizontal pointing?

Discussion in 'OnBoard Electronics & Controls' started by Squidly-Diddly, Aug 26, 2016.

  1. Squidly-Diddly
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    Squidly-Diddly Senior Member

    Only ones I've seen only offer 1 in 360 degree accuracy for phone's position on compass, or 1 in 360 degree for tilt either front back or L/R. (port or starboard for you old sea dogs).

    Why? I'm trying to make a homemade Total Station......

    http://www.tigersupplies.com/Depart...rtorder=3&showsubcategories=False&categories=


    .......using a digital level w/laser ( and a rifle scope mounted on the level since laser is kinda weak in daylight) and a smart phone (no compass feature on digital levels), and tap a hole into the level to mount on standard cheap camera tripod.

    For now, my 100ft tape measure should be good enough to get one distance and do the rest with trig.

    This isn't to replace a $4000 Total Station, but should be plenty good for rural use to get accurate "lay of the land" and an independent means to double check important features one last time before a big concrete pour. (never ceases to amaze me how often big construction firms make massive mistakes on big pours, even after top pros and their toys give the A-Ok....yeah the Total Station is accurate to within 1.5mm at 1000M, but somehow the footing ended up 5ft from where it was supposed to be. no one enters the data into a CAD program and sees if it more or less 'fits' when laid over blueprints)
     
  2. CDK
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    CDK retired engineer

    An Android app with better than 1 degree accuracy doesn't make sense because the hardware simply isn't good enough.
    A professional gps has a temperature compensated frequency reference to allow precise calculations, compared to that a tiny smartphone gps is just a toy.
     
  3. Squidly-Diddly
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    Squidly-Diddly Senior Member

    so besides a $4000 Total Station, where does one get a compass able to read .25 angles of accuracy or better, and doesn't weight 800lbs?

    I'm not even sure a Total Station knows where it starts out pointing to a high degree of accuracy, it might only know where it IS pointing in relation to where it WAS pointing, in a given session, at least as far as compass.
     
  4. CDK
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    CDK retired engineer

    A Furuno C-500 fluxgate compass has 0.1 degree resolution with 0.5 degree accuracy. That is about the best you can get without taking another mortgage on your property.

    The surveyor we hired last year had both optical instruments and a professional gps on a tripod that needed 10 minutes warmup before the ready light came on. He used it for reference only but said the optical instruments were definitely more accurate and faster.
     
  5. Squidly-Diddly
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    Squidly-Diddly Senior Member

    I think I'll be able to get .5 degree out of a smart phone by taking the points where it changes whole degree readings and taking the centers.

    $500, 14v, operates down to 0degs (C?), and I've gotta figure out my own readout screen?
    http://www.simrad-yachting.com/en-US/Products/Compasses/FC40-Fluxgate-Compass-en-us.aspx

    How about radio direction finders? There is some crazy outdoor activity sort of like "hide and seek" where a beacon is set up and the players with radio direction finding equipment track it down.

    For my purposes it would only really matter that all the points on a given "shoot" are accurate in relation to each other.
     
  6. gonzo
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    gonzo Senior Member

    RDF's are not going to be as accurate as you need. What are you measuring? A sextant can be accurate to 0.5 minute.
     
  7. Squidly-Diddly
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    Squidly-Diddly Senior Member


    Measuring layout for construction. Concrete footing forms and set in concrete steel plates, etc.

    The idea would be to have a simple easy to use and understand, and fully independent, method of double checking vital layouts before a big pour.

    Problem is a real Total Station is kinda complex so there will be only one guy able to use it, and people still make dumb mistakes because the readout is kinda hard to translate to the plans. Its not that something in off an inch, it will be that someone used the wrong number and its off 3ft.

    I'd want to take simple distance measurements with 100ft tape measures, and angles with a simple homemade Total Station, put those into a SolidWorks drawing and see if reality matched up with Blue Print drawings and dimensions in all respects.

    PS-I never understood how a sextant could be that accurate taking readings on the water, bobbing around on anything smaller than a supertanker.
     
  8. gonzo
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    gonzo Senior Member

    The sextant will not be able to take measurements that accurate on a moving platform. However, it can on land.
     
  9. Tiny Turnip
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    Tiny Turnip Senior Member

    levels? hosepipe level...

    Its a long time ago, but I've done levels with a hosepipe level. Bit faffy, but accurate and easy to understand. Would that help if you're needing levels? For some of the work, we taped the end 4 or 5 feet to a piece of timber to make a kind of staff at both ends - helpful for larger level differences.

    There's a ready made kit here:

    http://www.ebay.co.uk/itm/25-METRE-...ES-/141233735207?_trksid=p2141725.m3641.l6368
     
  10. gonzo
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    gonzo Senior Member


  11. Barry
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    Barry Senior Member

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