forum.supercharge.info

False Precision of GPS Data or: Please Stop Using More Than 6 Decimals

Dear Supercharge.info Editors,

I’m not sure if this recent trend is intentional or not, or even where exactly these numbers are coming from, but I have started to see new supercharger locations being added whose GPS coordinates have more than 6 decimal places. I haven’t checked all such instances, but for the few I recall offhand it is at least 11 decimals being used. Whichever of you are doing so, please stop.

Mostly I find this practice annoying because it means that the flags opened when clicking on a dot/cone are now appreciably wider/larger and cover up more of the nearby area of the map [as an example, compare the flags for Strathmore, AB (14 decimals) and Medicine Hat, AB (6 decimals)]. But also, as a matter of principle, 11 decimals suggests that the coordinates are specifying the location of the pin down to a precision of about +/- 1 micron. This is patently ridiculous. Using just 6 decimals gives a precision of about 4 inches or 11 centimeters, and is still more precise than is needed for the use this site makes of them. Really, I’d suggest considering even fewer, but 6 seems to be the existing standard for the site and is what Google Maps gives by default. So, I’d understand sticking with that. If you’d like to know what each decimal place roughly means in terms of precision, this Stack Exchange answer does a good job explaining.

Ideally, someone could go to the database and automatically adjust the number of decimals that it accepts in the fields for GPS data, but not knowing how the database is set up and edited I have no idea if this is possible. If it’s not, and you all don’t want to spend some tedious time trimming by hand, I’ll certainly understand and can accept just a cessation of the practice of using longer decimals going forward.

Thanks.

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I agree, I’ve been changing these back to 6-7 decimals on occasion. I find this xkcd is relevant :slight_smile: https://xkcd.com/2170/

Tip; when you right click in Google Maps and choose “what’s here”, the co-ordinates provided are 6 decimal places. These are the ones which I use.

3 Likes

At the moment Tesla seems to have up to 8 decimals on their findus site. But I looked only at about 3 sites. I guess they had more decimals in the past, since some sites in China are in this list of “the worst” GPS position sites (We do not have an editor that takes care of Chinese entrys so they are just copied from the Tesla website):

Supercharger GPS
Alpharetta, GA 34.071582182397215, -84.27540421485
Auburn, WA 47.29797566781793, -122.2482740879
Berkeley, CA 37.89873589942231, -122.3086720705
Blanding, UT 37.6255534, -109.47384199999999
Brownsville, TX 25.95011501991807, -97.488512992858
Cheektowaga, NY 42.90740960046357, -78.762238919734
Chicago - O’Hare Intl. Airport, IL 41.99870660096533, -87.888457775115
Clara Barton - Southbound, NJ 39.69808200226552, -75.396852493286
El Cerrito, CA 37.89857504336197, -122.30073004961
Farmville, VA 37.27217454798705, -78.401913642883
Fishkill, NY 41.52727858284335, -73.893152475357
Flushing, NY 40.76082142105967, -73.82967531681
Gilroy - Gilroy Crossing, CA 37.000817603650134, -121.5543383359
Glendale - Cooper Ave, NY 40.707962129071916, -73.86716723442
Grand Forks, ND 47.887974436939366, -97.08076357841
Hannibal, MO 39.71868338430419, -91.392382979393
Hattiesburg, MS 31.322700515282403, -89.38187956809
Hermosa Beach, CA 33.86495467766977, -118.39481949806
Hudson, WI 44.96446392129554, -92.725435495376
James Fenimore Cooper - Northbound, NJ 39.980901892306555, -74.88811254501
Jamestown, ND 46.88465891260407, -98.719555735588
John Fenwick - Northbound, NJ 39.696092520737224, -75.39582252502
Las Vegas - Alta Drive, NV 36.16847431885123, -115.28682857751
Leon Springs, TX 29.665289479310314, -98.63338708877
Lincoln, CA 38.869969245376666, -121.3031870126
Los Altos, CA 37.39889463423229, -122.11068212985
Madison - Southbound, CT 41.29159262475606, -72.579079270362
Manhattan - Vesey St, NY 40.714061544732544, -74.01583671569
McComb, MS 31.24847949104414, -90.471779108047
Meriden, CT 41.52701754109591, -72.77398198843
Metter, GA 32.3785661110323, -82.0625388622284
Michigan City, IN 41.673833415189605, -86.89123392105
Milpitas, CA 37.43453580769586, -121.891387403
Mitchell, SD 43.701129, -98.04449999999997
Montauk, NY 41.035822494064554, -71.94386780261
Newport News, VA 37.1142333351064, -76.4944982528686
Ontario, OR 44.025817827968794, -116.9425213336
Palm Coast, FL 29.475857757975774, -81.20644211769
Portage, MI 42.242426438302516, -85.58839380741
Reston, VA 38.94872939211095, -77.338449954986
Richard Stockton - Southbound, NJ 40.17811916819044, -74.630556106567
Richmond, IN 39.86825463042846, -84.886325597763
Rolling Meadows, IL 42.04970212081785, -87.99491485352493
Santa Cruz, CA 36.978635227811466, -122.0139670372
Scotts Valley, CA 37.04760773777563, -122.0277428627
Sealy, TX 29.742861050300064, -96.3310432434
Skowhegan, ME 44.78030435494409, -69.727027416229
Smithfield, NC 35.50530838717969, -78.328201174736
Somerset, PA 40.0173833333, -79.0771166667
South Padre Island, TX 26.08143518597012, -97.161090373992
Spokane, WA 47.59035879766457, -117.5616797804
Springfield - Morris Ave, NJ 40.718564588077676, -74.3296149373
Walt Whitman - Southbound, NJ 39.88533929938076, -75.002825260162
Waterloo, IA 42.45905780191561, -92.327889204025
Woodrow Wilson - Northbound, NJ 40.17638132122237, -74.628989696502
Manchester South (SC), UK 53.43029524048801, -2.1793752908706
Chiayi City, Taiwan 23.496492425305245, 120.38757741451
Hsinchu City, Taiwan 24.80726568472875, 121.036114096641
Taipei - Xindian District, Taiwan 24.985610682741523, 121.53984904289
Stockholm Infracity (SC), Sweden 59.5006239, 17.926818000000026
Storlien, Sweden 63.31038084103075, 12.1095085144042
Maribor, Slovenia 46.533247845, 15.6993663311
Demänova, Slovakia 49.05463888888889, 19.5788333333333
Aleksinac, Serbia 43.52878953338224, 21.7093813419342
Zarechye, Russia 55.695015028348976, 37.380434274673
Åndalsnes, Norway 62.55772975838314, 7.68532812595367
Gol West, Norway 60.697433066207715, 8.9534776438864
Hernes, Norway 60.93304006766471, 11.675945520401
Jaren, Spydeberg, Norway 59.61780944477983, 11.0044223070144
Lærdal, Norway 61.0644288433132, 7.509793639183045
Levanger, Norway 63.73445322567873, 11.2811243534088
Liertoppen, Norway 59.808633535359775, 10.299022793769
Mo i Rana, Norway 66.30771530119445, 14.1522681713104
Mosjøen Handelspark, Norway 65.84173732179684, 13.187839303333
Rugtvedt, Norway 59.03742214702959, 9.67426657676697
Skarnes, Norway 60.24821823163877, 11.743370890617
Skei, Norway 61.575568998637955, 6.4837199449539
Vikeså, Norway 58.63192047285978, 6.07776761054992
Volda, Norway 62.146610198095566, 6.0881423950195
China, Mexico 25.755923188469275, -99.37760353088
Ensenada, Mexico 31.86629385442327, -116.66216880083
Adda Nord, Italy 45.511805497815615, 9.6356105804443
Adda Sud, Italy 45.510579991189736, 9.6355032920837
Forlì, Italy 44.24287788398062, 12.0818281173706
Egilsstaðir, Iceland 65.2670238558026, -14.395877122879
Debrecen, Hungary 47.5412661280893, 21.5835750102996
Fót, Hungary 47.580072078966325, 19.162430763244
Szeged, Hungary 46.27415222360221, 20.10498046875004
Aichstetten, Germany 47.8804833333, 10.0397833333
Berlin (SC), Germany 52.394056600621724, 13.542307019233704
Huittinen, Finland 61.168440088350515, 22.68009987173
Kokkola, Finland 63.830141443921285, 23.148574233055
Beijing - Wangjing District, China 39.993602254871945, 116.46941184997
Hefei - Swan Lake, China 31.818100282208604, 117.23207116127
Hengyang - Linyin Hotel, China 26.8913548155, 112.5532900737
Hong Kong - Ma Liu Shui, China 22.41192118510221, 114.211399555206
K11 Atelier - King’s Road, Hong Kong 22.291464035383214, 114.2074567079
Maoming - Dongyuan Hotel, China 21.6696178073, 110.9330452535
Shanghai - Gigafactory 3, China 30.87231952066479, 121.766710281372
Shanghai - Gubei, China 31.188757751934183, 121.40182256698
Yibin - City Celebrity Hotel, China 28.7494054464, 104.6050000142
Abbotsford, BC 49.05800751461047, -122.37812519073
Bancroft, ON 45.084312584947156, -77.86111593246
Batchawana Bay, ON 46.946197347005494, -84.574585855
Blind River, ON 46.185186178965665, -82.92711138725
Cache Creek, BC 50.81097883213857, -121.3249450922
Castlegar, BC 49.29458943888519, -117.65346765518
Chicoutimi, QC 48.40191297319655, -71.062555611133
Deep River, ON 46.10165558297276, -77.48764514923
Fort MacLeod, AB 49.72499119541202, -113.39733611111
Kincardine, ON 44.172612682415405, -81.61596179008
Kitchener (SC), ON 43.46129483302286, -80.47230541706
London, ON 42.91735751697375, -81.208504736423
Maple Creek, SK 49.908628083528, -109.4720649719238
Moose Jaw, SK 50.40531401220693, -105.53349852561
Nakusp, BC 50.241441448485894, -117.8082203865
North Bay, ON 46.331698735974335, -79.47200775146
Princeton, BC 49.457882344218355, -120.5062249302
Quispamsis, NB 45.41814285737368, -65.9439754486
Red Deer County, AB 52.21632380847957, -113.81514072418
Strathmore, AB 51.03843912170862, -113.37860584259
Terrebonne, QC 45.727921615599925, -73.51101815700532
Upsala, ON 49.04158144013004, -90.468785762786
White River, ON 48.59215731603801, -85.27263879776
Whitewood, SK 50.33613431022413, -102.25744843482
Plovdiv, Bulgaria 42.144521200076085, 24.768837690353
Wavre, Belgium 50.707559, 4.597822299999962

I will go through the european sites. Any takers for North America?

1 Like

Well, I do know who added all of those sites, but I’m not gonna say who (though it’s probably obvious by the way this comment is structured). Anyway, the way I go and add locations on Supercharge info via the GPS coords is by copying what it shows on the OpenStreetMap when I make myself a custom pin.

So, sorry for the “mistake”. I’ll be a taker, since it’s sorta my fault, but note that I can’t really do it now cause I’m on vacay in Toronto. Maybe next week.

2 Likes

It’s nice to see the xkcd article confirms what I worked out empirically: for supercharger GPS locations there’s no value beyond the 4th decimal place. For the few locations where I’ve suggested coordinates (e.g. Eurocentral, UK) I took a little pride in making decimal places 5 and 6 equal to zero :blush:

Holy smokes, OSM is using 14 decimals?!? That’s specifying the location down to about +/- 1 nanometer. Lol.

I’ve been going through some of the North American ones. Just a few whenever I get a chance. I find it easy to open the “Data” tab and scroll down the list that way.

3 Likes