ABGPS/IMU Data Collection
ABGPS/IMU Data Collection
GPS/IMU Data Collection and Validation for Accurate Acquisition of Airborne Imagery and Photography
Collection of GPS/IMU data is the cornerstone of accurate and reliable airborne imagery or photography. That’s why we use a tightly coupled GPS and IMU (inertial measurement unit) for all of our projects and deliver them along with the image data to our clients and partners.
During the acquisition of aerial imagery or photography, the onboard GPS (or GNSS) accurately captures altitude, latitude and longitude coordinates so the absolute location of the camera is recorded as each image frame is collected. Simultaneously, the IMU is recording details on the attitude (pitch, yaw and roll) of the aircraft at the instant of each frame acquisition.
This combination of information from the GPS and IMU is critical for photogrammetric processing of geometrically accurate imagery, whether digital or film. It not only results in higher quality imagery, the GPS/IMU dramatically reduces the number of ground control points that must be surveyed in concert with the flight – decreasing the overall cost of the mapping project.
In addition, our field crews perform the ground surveying required to validate that our GPS/IMU data collection is accurate within the specifications of your project.
NovAtel SPAN-SE GPS/INS Receiver (GNSS)
Midwest Aerial takes pride in acquiring imagery and photography over your area of interest when you need it. And we get it right the first time. That’s one of the reasons we use tightly coupled GPS/IMU (inertial measurement unit) systems for accurate and reliable acquisitions of both digital imagery and film photography.
Since 2009, we have relied on the NovAtel SPAN-SE dual frequency GPS/INS (also known as a GNSS receiver). Since adding this unit to our inventory, we have never had to re-fly a project area due to poor airborne GPS data.
Our GPS is tightly coupled with the onboard IMU to collect accurate GPS position points during the acquisition process, which dramatically reduces the number of ground control points needed for processing. When the imagery is processed, the GPS or GNSS location data is used to georeference the image data to its correct location relative to the ground.
Inertial Measurement Unit (IMU)
To ensure accuracy and reliability, we tightly couple our Airborne GPS receivers with onboard Inertial Measurement Units for both digital and film acquisitions. After careful consideration and inflight testing, we have selected the iMAR F-SAS IMU, which we have relied upon since 2009.
As the tightly coupled NovAtel SPAN-SE airborne GPS collects position points during the acquisition process, the IMU records velocity and attitude data that maintain the position solution even when GPS signals are blocked by the aircraft wing during steep turns. This allows us to complete our flight lines faster than would be otherwise possible.
The SPAN technology tightly couples the GPS and IMU during data collection to provide unparalleled accuracy and reliability. Integrated post-processing of the GPS and IMU data is completed in a single step for precise positioning.