Path: ...!3.eu.feeder.erje.net!feeder.erje.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail
From: VanguardLH <V@nguard.LH>
Newsgroups: comp.mobile.android
Subject: Re: app for precision coordinates
Date: Mon, 24 Jun 2024 12:27:26 -0500
Organization: Usenet Elder
Lines: 100
Sender: V@nguard.LH
Message-ID: <1ib29f50d2bbn.dlg@v.nguard.lh>
References: <v-mdnaydDOIxuOX7nZ2dnZfqn_WdnZ2d@giganews.com> <v59arj$c11r$1@dont-email.me> <UKCdnUA20PinqOX7nZ2dnZfqnPqdnZ2d@giganews.com> <mwyu27wqkwt2.dlg@v.nguard.lh> <WdydnaYcj68u0uT7nZ2dnZfqnPudnZ2d@giganews.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: 8bit
X-Trace: individual.net QcNss6N1E2yfhB3839wDNws6FKbGaMCrgvLT+ea95w+ZzZJmSU
Keywords: VanguardLH,VLH
Cancel-Lock: sha1:cUWwGFbotDcFAOoRw2DovCS2lvg= sha256:5iiCtBcA24dq8rvF5j+hHjUCpC4slFHqIgKCR2T9bfQ=
User-Agent: 40tude_Dialog/2.0.15.41
Bytes: 6665

bad sector <forgetski@_INVALID.net> wrote:

> On 6/23/24 16:34, VanguardLH wrote:
>> bad sector <forgetski@_INVALID.net> wrote:
>> 
>>> On 6/23/24 10:18, knuttle wrote:
>>>> On 06/23/2024 9:39 AM, bad sector wrote:
>>>>>
>>>>> How would I map with precision about 900 planted trees on
>>>>> google-earth-pro? As a manual method I would think of taking a hundred
>>>>> readings on each with my phone and averaging them out, but that is a
>>>>> LOT of work (did it once with a bubble-sextant to win a bet). Is there
>>>>> an fdroid app to do this sort of thing (not interested in signupware)?
>>>>> Any other ideas?
>>>>>
>>>> I don't know about the  android version, but on the PC version you can
>>>> add pins to identify a specific location.
>>>>
>>>> On the PC version of Google Earth Pro, you can determine the longitude
>>>> and latitude to six decimal places or get good numbers for location
>>>> about 300 feet apart.  This 300 feet was calculated by zooming Google
>>>> Earth to its maximum and reading the coordinates of each location.
>>>
>>> About 1/3 of the trees are now just big enough to show on GE but the
>>> rest are not visible yet. It is to place THESE that I need the
>>> lat-longs. And I'm looking for about one foot of precision :-) which is
>>> not easy with the imagery resolution provided out here in the sticks. If
>>> I were living in the densely populated areas a six inch seedling would
>>> show but all I get is about a 1.5-2.0 foot circle to show.
>>>
>>> During a drinking marathon I once bet with the owner of a hotel I was
>>> staying at that I could measure the width of his hotel with a
>>> bubble-sextant to within a foot. So I took like a hundred readings on
>>> two corners, plotted them and marked the center of each 'blob'. Won the
>>> $200 bet which today would be like $2000. If I were a codepuncher I'd
>>> try to write an app that plots for maybe 30 minutes and then coughs up
>>> the centerpoint of the same sort of blob as the position.
>>>
>>> I'll be planting another hundred or so in the next three months so I'd
>>> like to refine my mapping. 220 of the trees are yellow-cedars not native
>>> here and many fans are watching to see how they will survive. I want to
>>> map them on GE and update the pictures from time to time.
>> 
>> I would think GPS would work to record the locations of the trees.
>> While different GPS receivers have varying levels of accuracy, even your
>> phone's GPS radio should suffice.  After all, the trees have to be
>> planted far enough apart to account for their canopies.
>> 
>> https://crec.ifas.ufl.edu/media/crecifasufledu/extension/plant-pathology-/greening/pdf/GPSAccuracyforTreeScouting.pdf
>> https://fruitgrowersnews.com/article/precise-gps-systems-increase-planting-efficiency/
>> 
>> Since you are at site when planting the trees, use GPS to record where
>> you planted.  Then use the GPS coordinates, or convert to long-lat, to
>> position in a map.
>> 
>> GPS radios in smart phones are accurate to within 3 to 5 meters (1o to
>> 16 feet).  Don't know far apart you are planting the seedling to account
>> for their canopy sizes later in life.  If a smart phone's GPS isn't
>> accurate enough, you can buy GPS receivers that are more accurate.
>> 
>> I figure if a hand-held GPS navigator is good for recording trails that
>> it is probably sufficient to record tree locations.
> 
> thanks for the time to respond
> 
> I once bought a garmin gps camera attachment for my slr camera but it 
> too was wishy washy; never even tried composing blobs with it. With 900 
> trees (and growing) the only 'involvement' I have time for is putting 
> the smart-phone down and leaving it there to collect its wanderings over 
> maybe fifteen minutes or less. The trees are at different distances but 
> what I want is 1-foot accuracy not so much because it's indispensible 
> but because I'm a sucker for at least a semblance of reality. 
> Google-Earth placemarks is one tool I use giving the trees icons 
> representing the tree species. Ideally I'd like to attach an actual 
> photo of the tree to appear in a popup on click or something along those 
> lines and all of it uploaded instead of locally stored.
> 
> Not sure if math averaging would give the same result as hitting the 
> center of plotted coordinates but with the processing utility in a phone 
> an APP could ideally produce the ultimately VERY accurate result ...just 
> like I once did with a bubble sextant meant to produce plots in terms of 
> miles at the center of triangles of probabilty. That stunt took half an 
> hour per reading and I did maybe fifty on each of two corners, I forget 
> the actual number, it was a royal pissing contest :-)

I think averaging would only work well if you managed to get the GPS
device connected to different GPS satellites within reach.  Then repeat
by using another different set of 3 GPS satellites.  I would think
reusing the same 3 GPS satellites to get multiple readings from them
would result in the same offset (inaccuracy) in each reading.  However,
maybe walking around in a circle around the focus point to take multiple
readings might work to average the multiple readings from the same set
of 3 satellites.

Someone here mentioned DGPS (differential GPS) which uses ground-based
positioning stations.  Those have a 200-mile range if there are no
blocks to the signal (mountains, trees, buildings).  Never got around to
using those, so no experience with them.  Don't remember seeing a smart
phone stating it can use DGPS, so you'll likely have to find a GPS
receiver that can find DGPS stations.