Infinite Flights' global terrain database covers the vast majority of the earth. From coast to coast and sea to sea, virtual pilots can enjoy a world of beautiful satellite terrain imagery and landscapes they may not otherwise ever witness.

This is true until you reach about 60°N or 60°S in latitude, where your beautiful mountain landscape suddenly becomes completely flat. Your arctic supply run has just been interrupted by steamrolled terrain. What's going on?

Shuttle Radar Topography Mission

In February of 2000, NASA's space shuttle Endeavour embarked on an 11 day mission to obtain digital elevation models of most of the earth's surface. By using two radar antennas, SRTM was able to use a technique called interferometric synthetic-aperture radar to create digital elevation data. This was then processed into tiles.

This NASA image used Landsat data to texture-map the surface created using SRTM Elevation data.

SRTM also contains so-called void filled areas. These are areas of the earth where mountain peaks or canyons make it difficult or impossible for the aircraft to collect all of the data required. Researchers have developed algorithms to interpolate data for these areas.

What happens north (and south) of 60?

According to a SRTM paper published by NASA, the Shuttle orbit of 233 km at 57° inclination was the highest possible for a fully loaded Shuttle. Maximizing the altitude also maximizes the antenna footprint on the ground, contributing to achieving full circumferential coverage in 10 days of mapping. Polar ice topography also changes at a more constant and faster rate than land masses, so it made sense for NASA to focus their efforts on maximizing data coverage on areas between the poles.

C-130 inspecting missing data in Alaska

What does this mean for Infinite Flight? We use SRTM data to create a virtual terrain database. Without it, all of our satellite imagery is flat.  We're limited by the data that we have at our disposal. In addition to this, we also have to make sure that streaming this data while you fly is possible.

We are currently looking at new datasets that will include the missing data. This can often be tricky due to the fact that the data may be hundreds of gigabytes in size. Once it’s available and processed, we'll be able to stream it straight to your devices. Until then, sorry, glacier hunters. Your expeditions will have to wait.