Path: ...!3.eu.feeder.erje.net!feeder.erje.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: VanguardLH 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: 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 wrote: > On 6/23/24 16:34, VanguardLH wrote: >> bad sector 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.