GPS on iPhone apps etc

[JD-Kid]

Hi guys
might be in wrong place so mod's. can move
ok. here is what I'm wanting to know. is there any apps. etc. that will work on a iPhone for GPS
what I want it for is to maybe follow lines drawn on a map and entered in to a phone or to have it put in ab lines off a first line
thinning a block of trees at the moment and needing to cross rows leaving about 16. trees standing between. cuts so about 35-38 meter apart lines
can it be done or better to use the compass on the phone and use that to set lines
I know in the past with using a handheld GPS unit the trees can affect the readings
any ideas would be great.

 

[Brisel]

Smartphone GPS has no correction signal so it will be sub 3m accuracy. Is that enough for you?

 

[Pheasant Surprise]

With some luck we might see the free Galileo high accuracy (HA) service start to become available next year.

That would be nice if it’s supported on new smartphone chipsets.

My guess is companies like Samsung and Apple will start announcing it on their next generation smartphones now along with early doors 5G.

 

[farmerm]

Smartphone GPS has no correction signal so it will be sub 3m accuracy. Is that enough for you?

I would say my phone GPS would only be accuracy to 3m on a good day, in an open field... in trees on the hills around Akaroa... I would expect the location could be out by 30m or more at times and dam near useless for anything more than telling you which hill you are on. The more satellites your device has line of sight with the more accurate the location should be... I think some of the newer GPS devices can work with more than one of the global positioning satellite networks simultaneously, thus increasing the number of satellites available to it at any given time, the American GPS is only one of 4 networks.

 

[Pheasant Surprise]

I would say my phone GPS would only be accuracy to 3m on a good day, in an open field... in trees on the hills around Akaroa... I would expect the location could be out by 30m or more at times and dam near useless for anything more than telling you which hill you are on. The more satellites your device has line of sight with the more accurate the location should be... I think some of the newer GPS devices can work with more than one of the global positioning satellite networks simultaneously, thus increasing the number of satellites available to it at any given time, the American GPS is only one of 4 networks.

Your receiver can look at all four global constellations, plus the two regional ones and still only be accurate to a few metres.

As said, correction is needed, either from space or terrestrial network.

 

[JD-Kid]

I did turn on the find me thing on my phone. for a start It said I was standing outside of the forest but with in a minute it had pin pointed me on a map
there was cell coverage. in that area.
the hand held GPS unit we used putting in plots had. me and another guy. walking all over the place trying to find the old plots in the end we. looked at. maps and just walked hoping we could see some paint markings from 5 years before hand

 

[farmerm]

Your receiver can look at all four global constellations, plus the two regional ones and still only be accurate to a few metres.

As said, correction is needed, either from space or terrestrial network.

The poster is looking to cut lines at "about 35-38 meters apart" so within a few metres might be close enough.....

 

[JD-Kid]

The poster is looking to cut lines at "about 35-38 meters apart" so within a few metres might be close enough.....

trees are. about 1.8 meters apart so. thats. close eneff and can always. count back along a row now and then to see how wider row/group being left behind
have a simple GPS unit in tractor here. bit bulky to carry in forest tho. and even that driveing up and down the road shows im in 2 diffrent places. by about a meter or 2 same lines each time tho

 

[Pheasant Surprise]

The poster is looking to cut lines at "about 35-38 meters apart" so within a few metres might be close enough.....

Possibly, depends on overlap and host of other things, like whether any sort of repeatability is important. Personally I think it's a going to be a bit too hit and miss without at least going to basic EGNOS correction. Unfortunately there is no free SBAS equivalent available in NZ or Ozzy (at the moment).

My post was addressing your quote "the more satellites your device has line of sight with the more accurate the location should be..."

Which unfortunately is not the case. There are advantages of looking at multiple constellations, such as more robust coverage (more satellites = more robust position), some faster convergence and better redundancy. But unfortunately there is no magic way it will gain you better accuracy. Not by itself anyway.