SQUID-5 NAVIGATION PROCESSING
Raw GNSS data received by the antenna mounted atop the SQUID-5 were recorded at 10 Hz by a dual-frequency survey-grade GNSS receiver, which was post-processed and differentially corrected against the Kings Beach, CA, (P150) continuously operating reference station (CORS) in Novatel's GrafNav software (v. 8.80.2720; https://novatel.com/products/waypoint-post-processing-software/grafnav
) to produce 1-Hz SQUID-5 trajectories.
The SQUID-5 trajectories, in combination with precisely recorded image capture event times, are used to generate SQUID-5 GNSS antenna positions at the moment of each image capture (2021-607-FA_Image_Locations.txt). The positions in the SQUID-5 navigation file represent the position of the SQUID-5 GNSS antenna reference point (ARP), not the position of the cameras or features photographed. To determine actual image positions, photogrammetric software such as Agisoft Metashape can be used to apply the lever arm offsets (in the camera frame of reference) from the GNSS antenna reference point to the camera lens. Using this method the following values for each camera were calculated for x,y,z in units of meters. Camera 13, 0.03536 m(x), -0.00407 m(y), 0.84721 m(z); Camera 30, -0.29259 m(x), -0.07655 m(y), 0.93223 m(z); Camera 39, 0.27623 m(x), -0.01498 m(y), 0.93657 m(z); Camera 82, -0.01679 m(x), -0.60744 m(y), 0.75020 m(z).