On 26 Mar 2021, at 06:25, Mccherry, Paul (Student) <p.mccherry@lancaster.ac.uk> wrote:

Thanks Robert

I am using the probe estimated geolocations to validate a new active geolocation method I am formulating.

The probe I that I thought had an anomaly was in fact found to be within 1k distance of my estimated geo location using the new method. The original discrepancy was due to a number of factors that I had failed to accurately apply.

However, I have other probes that have similar but different issues and whilst I am working my way through these issues any additional information you can provide would be greatly appreciated. 

Regards

Paul McCherry

Phd Student

Lancaster University.

 

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From: Robert Kisteleki <robert@ripe.net>
Sent: 25 March 2021 12:47
To: Mccherry, Paul (Student) <p.mccherry@lancaster.ac.uk>; ripe-atlas@ripe.net <ripe-atlas@ripe.net>
Subject: [External] Re: [atlas] Probe location obfuscation

 

This email originated outside the University. Check before clicking links or attachments.

Hi,

On 2021-03-25 13:00, Ponikierski, Grzegorz via ripe-atlas wrote:
> I would add to it additional problem that some hosts obfuscate probe
> location even more. For example you can find probes which in reality are
> located in US but are marked as CN or probes which are in reality in
> Wisconsin but are marked in California. Of course these are extreme
> cases. I guess most hosts just put a pin with probe location just
> somewhere around where it's locate as long it's in the same city. I
> don't remember, as a host of 3 probes, to get any precise
> recommendations how to mark probe location. Personally I just put a pin
> in city district where probe is locate.

We don't have strict rules about precisely how the hosts should
geolocate their probes -- and could not enforce those even if we had
them. Instead we recommend doing this "roughly correct", which for some
hosts means city / neighbourhood is good enough, for some others it's
the exact spot of the utility box at home :-)

> Can anyone confirm the geo-location obfuscation of probes as being up to
> 1km as per
> https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fatlas.ripe.net%2Fabout%2Ffaq%2F%23are-the-locations-of-probes-made-public&amp;data=04%7C01%7Cp.mccherry%40lancaster.ac.uk%7C0d707df0f3534cd8707008d8ef8c2bb3%7C9c9bcd11977a4e9ca9a0bc734090164a%7C0%7C1%7C637522732594157947%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=ZRNBZBO61oUXTYZGVYNyfyNRG2J4sv4AIrchzrCitOg%3D&amp;reserved=0<https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__https%3A%2Fatlas.ripe.net%2Fabout%2Ffaq%2F*are-the-locations-of-probes-made-public__%3BIw!!GjvTz_vk!EWq0OCOmS-1Af9zWmGzygQZxC02O19msR11hqwe7X3bHqvxoqX8Tt17N3fDKNB4%24&amp;data=04%7C01%7Cp.mccherry%40lancaster.ac.uk%7C0d707df0f3534cd8707008d8ef8c2bb3%7C9c9bcd11977a4e9ca9a0bc734090164a%7C0%7C1%7C637522732594157947%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=VdT77jYEFo5pWuPHqRjnowZPIq9neOLHKc%2B47slBNI8%3D&amp;reserved=0>
>
> I am a Phd student carrying out research on the RIPE atlas platform and
> an early result seems to indicate 1 probe has an obfuscation of 10km
> distance but this may be an anomaly or perhaps something not taken into
> account as yet.

We have a very simple algorithm that does the obfuscation consistently
with a certain maximum distance added, which may not be precisely 1km.
We can talk offline about the details if you're really interested in the
precise method.

Cheers,
Robert