Using GCPs as check points in pix4d project. Reviewing Quality Report in the Geolocation Details shows one GCP has Error Z (ft) of -1.567 feet. Other GCPs for the project show Error Z values of -0.282 (ft) and 0.146 (ft).
Looking at point cloud we see a variances around 0.3 (ft) inside of a radius of 11 (ft) from the GCP in question.
Just wondering how point cloud and GCP elevations can be so close, but the Error Z in the Quality Report can be so high.