# What determines the accuracy of the geotag?

#1

I’ve gathered quite some tweets and I spatially plot them based on the geotag.
Many tweets have the exact same geotag, and they are all less accurate than not-overlapping tweets.
The overlapping tweets all have 4 digits after the decimal, while many other have 6 or 8. Any ideas why this is?
I’ve seen too many tweets with the exact same (shorter) geotag to assume coincidence, neither is it the center of the bounding box. In the same area I haven’t been able to find another hotspot like this.

Thanks!

#2

Can you provide a couple examples?

#3

Sure,

I’ve got many tweets with location 40.7142, -74.0064 (Manhattan), both the latitude and the longitude have 4 digits after the decimal. Other tweets I’ve found have coordinates like: 40.71282431, -74.01226824, with up to digits after the decimal. The precision for the first coordinate is much lower than the second.

Why do some geotags have only 4 digits afther the decimal, while other have 8?

Things I’ve ruled out:

• Interference from buildings: there are many areas in Manhattan that have much higher buildings surrounding a point, that have more precise geotags. Additionally, I’ve found other tweets nearby the first geotag, with a higher precision.
• The center of a bounding box, the first coordinate lies in the southwester corner of the bounding box provided in the place element of the tweet.
• Bots: The text of the tweets highly suggest that it were humans sending those tweets. If it is a bot, humanity is doomed.
• Exact location: Perhaps those tweets were sent from exactly that spot, that a higher precision is not required (that the location actually would be 40.71420000, -74.00640000), but the chances of that happening for at least dozens (if not hundreds) of tweets are impossible.
• Jamming? Not likely

I was thinking that It may have something to do with the correction send by the cell towers, or lack of a ‘WAAS’-like system?

#4

Try looking at the source field (I believe it’s “source”) that tells you the app that published the tweet. I think you might be seeing tweets from desktop getting batched together due to having to guess the range off the ip instead of a gps system.

#5

Source for all of them is Instagram.com, they all link to a picture in the tweet.
I think it would be twitter.com or “web” if a desktop version of Twitter was used?
I’ve checked some other tweets, they also had instagram as source.