Racing with the Sun

“We’re mobilizing to the site.” Those words from our flight acquisition partner are music to the ears of geospatial supervisor Aaron Sale. It means we’re about to start acquiring the orthoimagery our clients need.

Orthoimagery is derived from high-resolution aerial photography and can be used for identifying and measuring – at highly detailed accuracy levels – just about anything on the ground. That’s why it’s so valuable for a range of infrastructure applications (a factor that distinguishes it from the satellite imagery easily available on the Internet).

Clients want the best imagery possible. For our Midwestern clients in Illinois, Wisconsin, Michigan, and Minnesota, that means imagery should be captured after the ground is free of snow and while the trees are still free of leaves. Aaron says “flight season” in the Midwest has only a four- to six-week window of opportunity for snow-free, leaf-off conditions. As if that weren’t challenging enough, as spring emerges from south to north, for any given area there are only about four to six days of ideal conditions for capturing images: a midday sun angle, a clear sky, and no high winds.

That’s an extremely tight and weather-dependent schedule, but Aaron says several factors encourage project success:

• Precise flight planning minimizes the time it takes to collect the imagery of a given area.
• Key team members are in contact on a nearly 24-hour basis to ensure quick response and action.
• Mutual trust and a good rapport with the flight crews makes the whole process much smoother and is probably the most important factor in a project’s success.

This spring Ayres and its orthoimagery clients are poised to complete another intense yet successful flight season. Despite the extraordinary winter of 2013-14, according to Aaron, the south-to-north progression of spring conditions has actually allowed for a fairly smooth acquisition season thus far. Ground conditions are good, but sun windows have been limited. But that’s typical, Aaron says.