GPS location correction

Hi, seems like my gps phone, hasn’t enought good coordinates and put the photos in the middle of the buildings.


Is this precision OK for the Mapillary purpose or I have to coorect the images location in any way?
Thanks in advance for your support,

Dear Norman,

To answer your question initially looked for ‘green dots’ by accounts with u/name ‘norman’ etc , as it helps to view the affected pics : found none using the filter option on www.mapillary.com/app?

First : there will always be some error in GPS location - even if the ‘error’ value indicates just two or three metres your track may be more like 12 of 15m off (for example caused by reflections of the signal off buildings along even a shallow ‘urban canyon’ streets, thus there’ll always be some error in placing pics ; that error will be both sideways and in the direction of travel , and the size of the error will vary throughout a session - for example increasing error under trees. .

Looking at the map fragment you shared : the solid green dots appear on the roadway, may be correctly placed ; looking at the ‘hollow-dot’ trail along the top: it would be clear from looking at the photos whether those were taken along the cycle track or on the roadway ; the alignment along what looks like a roundabout shows the effect of the GPS relying on ‘dead-reckoning’ from any number of previous determined positions to ‘improve accuracy’ ; which leaves the two ‘hollow-dot’ trails along the bottom : the one near the road would be obvious when viewing the pics, as would the one which cuts the corner and seems to pass behind the building.

That was a longwinded and merely personal opinion ; if you were to wish to adjust the position of that last ‘way-out’ track : I had a similar question some weeks ago, received two suggestions, which are in a small thread with the long-winded title Drag&drop to adjust geo-location? [Leaning towards the JOSM solution - once upload to Mpy works ; other two good alternatives] - #6 by koninklijke .

My personal and limited experience :
1/ if you’re able to work out where nodes in the GPS track ought to be - both time-wise and almost exact spot - @drivephotograph 's suggestion GPX Editor and Viewer (GPXEV) allows to simplify the track , drag/drop nodes then save and use to geotag your pics.
2/ to drag/drop a few dozen individual photos both @Gitne 's suggestion to use JOSM with the photoadjust and photo_geotagging plugins , and drivephotograph 's geosetter - with practice! - will produce excellent results, where - having tried both a couple of times - my preference tilts towards JOSM : based on the far more recent aerial imagery available for my part of Flanders, plus access to the official government map showing every kerb, lamppost and gully, which greatly helps in placing.

The above is of course no more than a personal opinion; with a bit of luck this reply will elicit responses and at some point your question will in effect be answered.

Met vriendelijke groet (Dutch for ‘with friendly greeting’),

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Dear,
I’m gratefull for your responses.
Indeed, all the traces in the photo, ara mine. I’ve taken several passes with the car.
Basically, because I’m the only one in my zone who upload to Mapillary and I want to well photo all my city (Amposta).
I feel calmer with your expertise opinions, thanks!
All the photos are taken with Samsung A32 5G, but 5G here means nothing (yet).
I’ll keep mapping all my streets several times and updating my town.
Warm regads,

Wouldn’t it be great if we could edit the location of our photos after we upload them?

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@MiguelAndrade ,

Edit next morning: rearranged paragraphs, removed duplicated info and added some clarifications.

Not all aware that behind scenes Mapillary puts in lot of effort to correlate with previously uploaded pics, aerial imagery and OSM (OpenStreetMap), after recognising traffic signs and blurring faces etc. they add those arrows which allow OSM contributors to view virtual panoramas, time-travel to other sequences along same way.

Can think of two reasons why contributors should correctly place pics before uploading: 1/ it takes extra effort to process recognised features which are discovered on pics with incorrect geo-location info and 2/ some of that work will be abortive in case geolocation info is adjusted later on.

Obvious solution is to use Drag 'n Drop utility to correct the gravest outliers before uploading; much appreciated browser-based webuploader was discontinued June 2021, but not all’s lost: the alternatives work faster, and more accurately to boot.

There are several ways to reposition your pics before uploading: tried two which were posted in reply to my question some weeks ago, after trial-and-error gravitated towards JOSM with photoadjust and photo_geotagging plug‑ins as per:

An other option is in @drivephotograph 's reply:

Soon as you’ve installed the preferred JOSM option (josm.jnlp with OpenWebStart environment) and familiarised yourself with how JOSM functions, JOSM works more accurately and faster than the departed web…l…der - but one needs to actually read various help and explanatory pages - also those for the plug-ins, make the correct layer active / (in-)visible ; the ‘update coordinates’ instruction is a bit hidden, but read and follow the instructions and all will happen as planned.

Probably helps that here in the Flanders part of Belgium one can add the most recent aerial pretty-high resolution imagery, and a plan which shows kerbs, lampposts and traffic lights, sewer covers: makes placing and aligning photos easier than a doddle.

In use, one doesn’t need to download nodes etc. from OSM: 1/ enable the two listed plug-ins and 2/ imagery relevant to your area, then 3/ drag+drop pics you wish to geo-adjust : to move insertion point drag, to adjust direction place cursor on a spot near the middle of pic, CTRL+click to see directional arrow turn.

@chrisbeddow : Further to your forum query: I’d appreciate a Mapillary plug-in for JOSM which allows me to reposition already published pics when I spot errors - both my older ones, and other contributors’ ; there is such a plug-in, but it doesn’t seem to allow to either drag or point? The OSM wiki on it was last updated April 2021 : would it still work with API v.4, please?

Met vriendelijke groet (Dutch for ‘with friendly greeting’),

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Thanks. How can I correct the location of photos that I upload via the iphone application?

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Why are you deleting all your posts the last couple days?

@Thibaultmol ,

Looking at Profile - GITNE - Mapillary Community Forum : the only remaining posts concern Mapillary joining Facebook : could it be that @GITNE discovered something so truly invidious that the only response is to remove the majority of forum posts?

It would in that case have been courteous to mention this in a good-bye post?

Just my tuppence, and of course based on conjecture and speculation …

Met -als immer- vriendelijke groet (Dutch for ‘with -as ever- friendly greeting’) <

Anybody knows when there will be an edit function again on the website to correct GPS location of our own uploaded pictures ? I really can not correct them all before I upload, I now have many sequences uploaded with gps errors near tunnels or high buildings. So I really need to correct…

@micmin1972

When it comes to correcting the GPS location, JOSM with the photoadjust and photo_geotagging plugins tends to work faster than the late Desktop uploader and -for my region- yields better results ; details in my post November 2021.

Met vriendelijke groet,

Hi @koninklijke,

I think you are referring to this thread, but I don’t see any details on your solution. Am I missing something?

Dear @mapfl ,

That thread was mutilated when one contributor removed posts, leaving gaps in the train of thought.

This reply based on assumption that you have a few dozen or a few hundred geotagged photos where either the location is incorrect or they point in the wrong direction - if not, please stop me here.

To drag-n-drop pics to adjust the location, and pick-n-click to adjust the direction of view, my preferred tool is JOSM with two plug-ins : photoadjust and photo_geotagging , using imagery (JOSMs term, for the satellite / map underlay) with sufficient detail.

Josm is available via Download – JOSM , where you can download either the windows installer, or the preferred auto-updating josm.jnlp , you’ll also find a link to the preferred Java environment , OpenWebStart. The windows installer will prompte to update every couple of months, the OpenWebStart / josm.jnlp version checks and updates itself when a newer version is available.

On https://josm.openstreetmap.de/ you’ll find Getting Started , read that, and also read the info on the plug-ins ; enable plugins and imagery via the Preferences pop-up window, which resides under the Edit entry ; you’ll also find instructions for the plug-ins under the ‘more info’ link with each plug-in in the plugins tab in the preferences window, ditto you can enable / disable maps and satellite pics in the Imagery tab.

Once set up JOSM, drag-drop the folder with pics to be geo-adjusted on the map window, pick the background map / sat.pic imagery of your choice, make sure you make the correct layer active ; on the right hand bottom edge there’s a cross to place the current pic in the centre ; zoom in / out with + / - , go to next / previous pic with pg dn / pg up , and most hidden : right click the geotagged images layer, look for the ‘update coordinates’ entry to write the changed geotag info to the files.

This is a concise story, takes a bit of time to actually read, ingest and understand the documentation, thereafter works really fast.

Met vriendelijke groet (Dutch for ‘with friendly greeting’),

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Thanks a lot Koninklijke. I’ve been working with JOSM for years but have never come across these plugins. Works like a charm, very helpful.

Koninklijke describes a good approach for pre-upload gps corrections. But I still wait for the post-upload correction facilities on the site…

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