Airborne Sensors

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Airborne Sensors

Airborne Sensing has been a leader of airborne sensor technology for over thirty years. The advent of digital image technology has provided us with further opportunities to showcase our adaptability in this field. See below for further information on our large format digital multispectral cameras, precise positioning systems, GNSS/IMU-based Position and Orientation System (POS), and our large format analog cameras.

Large Format Digital Multispectral Cameras
The latest digital aerial cameras and software surpass all analog solutions, and Airborne has identified one breakthrough technology as the very best: the UltraCam large-format digital camera developed in Austria by Vexcel Corporation (now part of Microsoft Virtual Earth). Combining our expertise in aerial photography with Vexcel’s standard-setting digital photogrammetry, we can provide the high-quality, verifiable images you need to map the world, and the uncompromising accuracy to make decisions with confidence.

Our Vexcel UCX features imagery with a better than 12-bit per pixel dynamic range (in contrast to film cameras at less than <br>8 bits per pixel), without any grain noise. The result is unrivaled radiometry with better matching accuracy, allowing for more flying days in marginal weather as well as better interpretability, better stereo and more successful automated processes.

Distributed parallel sensing via 8 optical cones assembles a large-format digital image in natural colour with false-colour infrared. Each of 13 area-array CCDs feeds signals into its own compact electronics setup and data path. The “master cone” provides a single-image coordinate system and control of geometric accuracy.

Each CCD array is supported by separate “private” processing and storage components, with capacity for dual-redundant storage. Using the UltraCam’s powerful onboard 15-CPU system, we can not only acquire images, but we can also begin preprocessing during flight. As opposed to our analog system, images can be fed into existing photogrammetric workflows using no-cost redundancy to vastly improve automation.

Precise Positioning
The Airborne Sensing team has developed an interface that sends the mid-point of an exposure signal to the GPS event-marker log. The GPS system notes exactly when the camera shutter was open at its mid-point and allows for the precise (less than 300 mu// µ) location of the perspective centre at the instant of exposure. Eccentricity parameters between the antenna phase centre and the optical nodal point are known to within 1 mm x,y,z. The system logs in-flight GPS data for further post-processing.

GNSS/IMU- based Position and Orientation Systems
The GNSS/IMU Position and Orientation System (POS) used by Airborne Sensing was developed by the Applanix Corporation. The GNSS/IMU POS collects GNSS positioning data during flight at 1Hz or 2Hz, and IMU data at 200Hz. It measures the position of the camera relative to the centre of the earth to less than 15 cm, as well as the angle of the camera relative to the mathematical surface of the earth to slightly more than 1/1,000 of a degree. Output from this device is then post-processed using GNSS/IMU post-processing and filtering algorithms to compute the x,y,z and w,p,k coordinates of the camera at the time of exposure. Results are immediately useable in a user’s analytical photogrammetric system for vector, image or other types of mapping.