Shadows and Suncalc

Calculating time using clues within a Google Streetview scene

Sector035
Sector035
Jan 4, 2019 · 6 min read
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I received a question from Micah Hoffman, who was doing some writing for his SEC487 OSINT class in regards to determining the time and date a Google Streetview image was taken. He was able to determine the time pretty close but did ask me to verify his findings and whether I had some additional hints. Honoured to be included in a SANS course, I will take you on a small hike along the several steps taken to determine the most probable day this scenery was captured by Google Streetview, followed by finding the exact time within that day.

Location and Surroundings

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Israel National Trail

On the left of this picture we see the power plant and to the northeast we see Sde Dov Airport. The shadows seem to be coming from the east, but that is simply not accurate enough to determine the exact time. We need to determine the direction of the sun and get as close as possible to the exact angle, and preferably we need the exact day this photo was taken.

Finding the Day

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Capture date

Looking at Google Streetview, we see it was captured in June 2015, but the exact day is not published. As far as I know it is not possible to find it in the meta data or responses that are sent to the browser or to Google Earth. So we‘ll be looking at something else.

If we look upwards, we see there is a heavy overcast on this particular day. Going over historical weather data of Tel Aviv in the month of June 2015 we find that only on one specific morning (yes morning, remember the shadow was coming from the east?) there was a heavier overcast compared to other days that month. Using that piece of information we have reason to believe this was the exact day this Streetview scene was captured.

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Clouded morning on June 28, via TimeandDate.com

The whole month of June 2015 can be viewed at the ‘Time and Date’ website here:
https://www.timeanddate.com/weather/israel/tel-aviv/historic?month=6&year=2015

Finding the Time

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Lining up the shadow of the metal shiny bollard with buildings in the back

To find where exactly the shadow is pointing at we need to find out which buildings can be seen in the background, so we are going to have a closer look at that. In the green we see a hangar or shed in the foreground. Behind that we see a line of multiple apartment buildings highlighted in orange, and left of it a few more buildings that seem to be closer together, highlighted in red.

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The scenery in the background

Since we know exactly where we are standing (to be exact, we are standing here: https://goo.gl/maps/eHwAEf4Xfw32) we can draw a line towards the direction we are looking at. By using clear satellite imagery that is at least somewhat close to the date we are looking at, we find we are looking at the buildings highlighted in red and orange.

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Matching our surroundings to satellite imagery

And the green circle is the building the direction of the sun seems to be in, which can be found by using the shadow we found earlier on and extending it all the way towards the buildings in the background. It is a bit difficult to see in the following screen capture, but do try it yourself!

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Extending the direction of the shadow

Let Tools do the Talking

In Suncalc we first set the date on June 28, 2015 and then place the marker right on the spot we were standing, which is the location where the concrete path changes to wood. Then we change the time until it lines up with the second building from the left within the ‘orange’ block. After sliding a bit back and forth, we find the following: June 28, 2015 at 8:29 UTC+3

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Using Suncalc to find the time

To double check our findings, we will have a close look at the ‘Azimuth’, or the direction of the sun, which is highlighted in red in the image above. If we go to Google Earth, we can determine the direction the sun is in, by using the ruler tool. For that you click on the ruler on the menu bar, then first click on the location we are standing (near the bridge), then we click on the second building where the shadow is pointing at. Google Earth will give us an angle of 81.86° which is pretty close to the 81.78° we found by using Suncalc.

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Determining the Azimuth via Google Earth

If you are able to find the direction via such an accurate way, then I personally would recommend you use that before using Suncalc. This goes especially in cases where the points that need to be lined up are too far away from each other, forcing you to zoom out a lot within Suncalc which will make any findings less accurate.

General Tips and Hints

Since in this case it was Google Streetview, it was easy to find a suitable spot that fit that criteria. A small warning though when doing this: Google Streetview sometimes stitch together different ‘runs’ that are taking at different moments in time. So do make sure that when moving around in Google Streetview you stay within the same ‘capture-sequence’ of that same day. Since there were people visible just north of the location discussed above I was able to confirm that the location I preferred to work with was indeed taken at the same time and date, and not a few days or weeks later.

Quiztime

Write-ups from the team behind Quiztime that describe…

Sector035

Written by

Sector035

Just a shadowy nerd… Busy with InfoSec, geolocation and OSINT

Quiztime

Quiztime

Write-ups from the team behind Quiztime that describe solutions to past Quiztime challenges, contain tips about geolocation and verification and will go deeper into the hints that sometimes can be found in a simple photo. For journalists, OSINT researchers and everyone else.

Sector035

Written by

Sector035

Just a shadowy nerd… Busy with InfoSec, geolocation and OSINT

Quiztime

Quiztime

Write-ups from the team behind Quiztime that describe solutions to past Quiztime challenges, contain tips about geolocation and verification and will go deeper into the hints that sometimes can be found in a simple photo. For journalists, OSINT researchers and everyone else.

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