2019 Bristol Bay, AK DMC 4-Band 8 Bit Imagery

The imagery was acquired by Quantum Spatial Inc.

Aerial Photography Capture: A twin-engine aircraft with an on-board camera, the UltraCAM Eagle model(serial #70914123) manufactured by Vexcel Imaging, GmbH, a 4-band frame-based digital camera with focal length of 80mm, was used to capture the imagery. The position and orientation of the aircraft was recorded at each exposure with the on-board global positioning system (GPS) and inertial measuring unit (IMU).

Aerotriangulation Process: The aerotriangulation was performed using the initial GPS/IMU data and was refined using conventional photogrammetric methods.

DEM Process: Autocorrelation was performed on the imagery and processed to eliminate all returns not classified as ground.

Orthorectification Process: Inpho's OrthoMaster software was used to process the imagery to remove systematic and terrain distortions while also georeferencing it. The resulting output files were output with a ground sample distance (GSD) of 0.2 m.

Mosaic Process: Inpho OrthoVista software was used to color-balance, automatically generate seamlines, and mosaic the individual orthophotos into user defined mosaic tiles.

Tile Review: The mosaicked tiles were each individually panned through and errors/blemishes in seamline generation and color balance are removed by manual methods. This data set was also compared to imagery previously collected, processed, and delivered to the client in order to shift the overall color cast of the current imagery to better resemble the legacy data.

Header Creation and Horizontal Checks: The mosaic tiles have their georeferencing information assigned into the headers of the tiles creating full geotiffs. The tiles are then checked for horizontal positioning utilizing ground control.