How is accuracy of Google Maps locations determined, and can it be altered?

Observers commonly use the search function to add locations to their observations, which uses Google Maps and results in many errors. One of these errors is that the circle of accuracy (precision) that comes with the location is often too small.

For example, I have a project on biodiversity of a protected area in Brazil, Murici Ecological Station. When searching for this protected area to add location to an observation, the default circle of accuracy is 210 m, which doesn’t actually extend to any of the forest within the protected area where virtually all observations are made (the large block of dark green to the north of the location shown in map below)! Google Maps seems to show the boundary of the 6116 ha protected area reasonably well, but the circle of accuracy is tiny by comparison, for no reason that I can understand. There are now over 150 observations of forest species, from 11 observers, mapped wrongly in the pasture.

I can’t see how to ask Google Maps to fix this, except by moving the location of the “place” to a more accurate location - which I have requested. Does anyone know how?

This issue was mentioned by @charlie back in 2019, and related issues discussed, but without any resolution:

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instead of selecting a place from the dropdown menu, just type “Murici Ecological Station” and hit enter.

You can also type in a manual accuracy number when you upload your observation.

In Google Maps, not the iNat interface, if you’re logged into your account you can correct locations. I don’t recommend doing so for things other than point locations though.

If you need to correct an entry, you can go to maps.google.com, and right-click anywhere on the map and it will give you latitude and longitude in a context menu. If you click on that coordinate in the menu, it will copy that coordinate to your clipboard. Then you can manually enter that coordinate via the iNaturalist website’s Edit Observation feature.

image

Hope that helps!

Edit:
Oy, I am too tired, I had to re-read your post like three times. If you’re talking about correcting other people’s observations, I imagine they would have to do this themselves. I’m new to iNat myself, but the best thing you can probably do for past observations is comment and ask users to fix them. Unless you’re actually taking a team out to do observations, then maybe bring a handheld GPS device with you?

I see what you’re saying though, I looked up the same location and it’s plotted in the dead center of empty land. Maybe try clicking “Report a map error” in the bottom right hand (if you haven’t already).

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Thanks all for the suggestions. I guess I was not clear enough that I am not talking about setting my own locations. I use the GPS on my phone and typically get locations accurate within 10 m, so that’s not a problem.

The issue is with other observers, most of whom I do not know personally. They are using iNaturalist’s default features, with a poor result. This is not just relevant to this project, but in many places around the world, as Charlie’s comment indicates. It’s a much wider problem.

Unless I am misunderstanding something, this has exactly the same result.

The odd thing is that the polygon in Google Maps appears accurate. What I don’t understand is how that results in a tiny circle of precision.

Exactly. I’m not going to ask other people, who have no idea who I am, to fix more than 150 observations. But I’d like to see if there is a way to reduce this problem recurring in the future. I hadn’t seen “Report a map error” but have tried that and will see if Google Maps gets back to me.

this is what i get:

what seems to be happening for me is that if you select from the dropdown list, Google returns the bounding box for a particular address via /PlaceService.GetPlaceDetails; whereas if i just hit enter, Google returns a bounding box for a place via /PlaceService.QueryPlaces.

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Interesting, I am now getting the same result. If that was consistently the result there wouldn’t be a problem. I’m not sure why it didn’t work for me previously.

When I try the same in iNaturalist Explore interface, this is what I get:

Do you have any explanation for why the different result depending on whether one hits enter or selects from the dropdown list, given that the address and coordinates are the same in either case? The only slight difference is that the latitude has more decimal places when selected from the dropdown menu, whereas the longitude stays exactly the same.

Thank you! What are the options for correcting this, and why are they so different?

Could iNaturalist choose only to get results for /PlaceService.QueryPlaces, and can we be confident that those will usually/always have larger precision values?

I’m not super familiar with how Google stores its data, but i would assume the address needs to be smaller for navigation purposes, while the place can be larger for mapping purposes.

i haven’t looked at the code in the Explore page’s location / place matching logic, but i assume what you’re describing would be the right approach, but you might only be able to go this direction if the location and place filters were decoupled completely so that matching was not done at all. (i actually think that would be a good thing, but it would probably require a change to the page that would more clearly allow users to explicitly switch between querying places from iNat vs Google.)

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That makes sense, thanks. I understood that the Location search gets Google Maps locations, while the Place search in the filters gets iNaturalist places - is that not so?

I found an example of where the /PlaceService.GetPlaceDetails appears to get a larger precision value than /PlaceService.QueryPlaces (but both are still appropriately large values, so wouldn’t be a big problem):

on the Explore page, if you filter from the Location box, it tries to match places from Google Maps to places in iNaturalist, taking the place from iNaturalist if there is a match. (The problem here is that the matching doesn’t always work as you would expect.)

if you search from the Place box, then it will get only places in iNaturalist.

hmmm… i guess the main thing is that getting the Google places from these two different routes in their API returns potentially two different results. without digging into this, i can’t tell you for sure exactly why this is the case. it could be something in the Google data, or it could be something about the way the Google Maps API works, or it could be something else. i’m not sure.

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If you’re talking about correcting other people’s observations

No, it’s about correcting locations in Google Maps, completely independently of iNat.

In Google Maps you can click on a place and then click on “suggest an edit” and make changes to Google Maps itself. You can also click on the hamburger icon and click on “suggest an edit” and make larger changes.

Since iNat interfaces with Google Maps passively you can’t make edits to Google Map locations via iNat, but you can do so from Google Maps itself.

This has nothing to do with the observations, but it has everything to do with this portion of OP’s question, “use the search function to add locations to their observations, which uses Google Maps and results in many errors.”

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