Need to borrow a GPS in Launceston region

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Need to borrow a GPS in Launceston region

Postby Lentara » Sun 11 Mar, 2018 2:44 pm

This is a bit of a strange request, however I need to borrow an accurate GPS for a day to survey my property boundary. Sadly I don't think my iPhone GPS is accurate enough for the job as the coordinates jump around too much and it really needs to be accurate to within 20cm. Preferred accuracy would be to 2 decimal places of a second. I would be exceptionally grateful as I'd prefer to avoid buying a GPS if I can as my iPhone is normally good enough for most uses, particularly with Memory Maps loaded onto it.

Thanks in advance for reading my request,
Cheers
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Re: Need to borrow a GPS in Launceston region

Postby Warin » Sun 11 Mar, 2018 3:52 pm

:lol:
Yer dreamin if you think a common GPS has that accuracy.

If you need 20 cm accuracy .. hire a surveyor.

https://gis.stackexchange.com/questions ... acy-of-gps
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Re: Need to borrow a GPS in Launceston region

Postby Geevesy » Sun 11 Mar, 2018 4:10 pm

Yes I second Warin’s comments. Cadastral if you want to look at your boundaries.
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Re: Need to borrow a GPS in Launceston region

Postby ChrisJHC » Sun 11 Mar, 2018 4:21 pm

From memory the best my Garmin would claim was to be accurate within 8 m. Probably not good enough for your purposes.


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Re: Need to borrow a GPS in Launceston region

Postby michael_p » Sun 11 Mar, 2018 6:14 pm

General purpose GPSr units have an accuracy of approx 3m and that is on a good day. To get any near 20cm accuracy you need a Differential GPSr. Search Google and see if a DGPSr can be hired.

Geoscience Australia had a service where you could upload gps data, that you had collected over a 24hr period with a regular GPSr and they could correct the data and give you a very accurate position. Not sure if this service is still available.

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Re: Need to borrow a GPS in Launceston region

Postby Geevesy » Sun 11 Mar, 2018 6:36 pm

Michael_p may be referring to AUSPOS which while yes is still around isn't really suitable for the purpose.

There are many problems associated with even attempting to do this yourself, equipment being one, being on the correct datum will be another, using the right field techniques etc etc. A surveyor has the training in all of this and as such obtains positions around <5cm fairly comfortably with RTK DGPS.

I'd be interested to hear what the purpose of this would be? If it's a dispute with a neighbour then observing any differences won't actually solve anything. Property boundaries are a touchy subject obviously and a Cadastral Surveyor will be your best bet.
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Re: Need to borrow a GPS in Launceston region

Postby taswegian » Mon 12 Mar, 2018 5:59 am

I echo the responses above.
But why do you need to survey your boundaries? What's the purpose?
I gather it's rural otherwise you'd pull out a tape.
What would you do if property fenced and you differed from your title measurements?

Re borrow a GPS. I doubt, you'd get one on free loan. They're expensive bits of gear for that accuracy.

Having no idea why post, but common concern from landowners is LIST showing boundaries off from fence lines.
There's a layer in LIST that indicates possible accuracy of boundary locations shown.
Even if they show as sub metre doesn't guarantee their position on the ground.
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Re: Need to borrow a GPS in Launceston region

Postby GPSGuided » Tue 13 Mar, 2018 2:57 pm

Don’t bother as consumer models don’t have the level of precision you need for property boundary determination. Some top end smartphone have more up to date chip than some outdoors GPS units, so don’t discount on that basis. In practice, you need proper surveyor gear.
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Re: Need to borrow a GPS in Launceston region

Postby Overlandman » Tue 27 Mar, 2018 5:49 pm

All of my property boundaries had a star picket driven below ground level. So my surveyor used a metal detector :?
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