Skybox Imaging is making it easy to monitor oil reserves and other resources from space. Oil is typically stored in tanks with roofs that float to avoid breathing and evaporative losses in the space between the top of the oil and the tank ceiling. With the roof’s moving and basic trigonometry, Skybox’s satellite images can be used to estimate the fill and volume of oil containers. The ratio of length of the tank shadow casted over the outside versus the inside is proportional to be volume of oil inside the tank.

Below is an analytics use case created by Skybox co-founder Dan Berkenstock and Skybox Product Manager Ty Kennedy-Bowdoin using two SkySat-1 images of the Ras Tanura Oil facility in Saudi Arabia leveraging Mapbox's visualization tools. Using the method described above on both images, it's possible to monitor the change in volume for each tank:


Ras Tanura Najmah compound, Saudi Arabia
Here is the math of how this works:
This method can be easily expanded. Aggregating the volume values using the radius and shadows plus sun elevation we can fill the values in the formula and estimate the overall storage for the facility and how much the ship docked on the first image could have taken on board.
  • Area of the cylinder: taken directly from the image since we know the resolution.
  • Height of the cylinder: Using the the length of the shadow on a flat surface and the solar elevation (from the time/place but also typically part of the image metadata).
Mapbox's satellite pipeline allows them to process all kinds of imagery sources into orthorectified single strips and beautiful global mosaics. Continued integration between Skybox and Mapbox will further simplify the process of accessing and analyzing timely satellite imagery.

 Posted by Bruno Sánchez-Andrade Nuño (Chief Scientist, Mapbox) and Dan Berkenstock (Chief Product Officer, Skybox Imaging)