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Comment by gruez | Hacker News Reader

How much accuracy can you possibly get from a 600x600 image?

From the regular images, probably not a lot. But if you see a plane crossing in front of the moon or the sun, you could determine a ground track of the shadow of the plane. If you get that with two different planes, you probably have a pretty accurate position (a few hundred meters). Combined with the image of the setup, showing a balcony, someone could probably find the exact location.

> If you get that with two different planes, you probably have a pretty accurate position (a few hundred meters).

What?! I've seen the viral guy on social media who can pinpoint places in the world by looking at a photo but... a few hundred meters based on the angle of the sun/moon? That's wild!

If you have time of the image accurate to the minute, and you know that the plane, sun and observer were on a line, the observer has to be on the ground track of the shadow of the plane during this minute. If you have that from two planes on different tracks, the observer has to be at the intersection of the ground tracks.

This method is not just from measuring the angle of moon/sun, but using the plane (which has a known position) as a marker. Just by using the angle of sun and moon, you need to be extremely precise. 1 degree error is 1/360 of the circumference of earth distance, that’s about 100km.

If you know the flight and the date and time you can easily pinpoint exactly where the plane was and where it was heading. Not incredibly challenging at that point to narrow in on roughly where the photos were taken from.

Well we already know it roughly, it's Indira Gandhi International Airport in New Delhi.

>If you know the flight and the date and time you can easily pinpoint exactly where the plane was and where it was heading.

You'd still need reference data from the photo to triangulate where it was taken from. A blurry 600x600 photo is going to have plenty of uncertainty.

>Not incredibly challenging at that point to narrow in on roughly where the photos were taken from.

Most people probably don't care as long as it doesn't pinpoint a specific address.

I'm under the impression that the OSINT crowd routinely comes to more impressive conclusions based on worse source material.

Those red-green navigation lights are enough. There is only one aircraft position which would satisfy a given relative configuration. PI camera has a known field of view and given hundreds of images one could have directions converging pretty accurately.

Nit pick, it's not using a Pi camera, its using an old Nokia 5.4 phone as a camera.

Also, they're showing (and linking to) FlightRadar24's departure and destination data, it's quite clear they are on one of the approaches to Delhi International (DEL). I don't know how many runways DEL has, but there's no more than 4 possible lines planes take in approach and departure. If i cared enough I could easily work out which of those lines by checking FlightRadar for the history of one of the links, and match the timestamp with the FR tracklog.

Collection 100s of images any attempting to do geometry magic is unnecessarily complicating things. (Which is fine if your goal is to solve complicated problems for fun. But there is a much easier way.)

Depends on how far from the airport you are, and the accuracy of the timestamp. If you have accurate-to-the-second timestamps and you're within maybe 10km of the airport I think you could get down to a neighborhood pretty easily.

You know roughly the perspective that the camera sees the plane from, so you take the plane position at that timestamp and project that perspective line down onto the ground. The higher the plane, the more error there is with estimating the observation axis, so the less accurate this gets.

Maybe if the sky is cut away around the plane, I guess you could still make out a shadow on the tube/from the wings/engine nacelle

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