Estimated Parallax offset for various heights seen from the Advanced Baseline Imager (ABI) or Advanced Himawari Imager (AHI)

According to the AMS, parallax displacements are "shifts in the apparent (or mapped) position along a reference ellipsoid of Earth's surface or atmospheric features (e.g., high terrain, clouds, lightning) due to non-nadir viewing geometry. Parallax displacements for features at altitudes above the reference ellipsoid occur in a direction away from the viewer, along the great circle defined by the subsatellite point and the subfeature point. The effect is maximized for high-altitude features observed at very oblique viewing angles, minimized for low-altitude features, and nonexistent for features observed at nadir". Also see the CIMSS Satellite Blog by Scott Lindstrom. Or these Satellite Liaison Blogs: Why is my GOES-16 Imagery Displaced? or GOES-East/West GLM Compared by Bill Line.

The readout values are read from an image that assumes a fixed cloud height. The underlying parallax displacement distance images were made with a maximum of 125 km for displacements, so no readout value on the earth should be larger than 125 km. No realtime cloud information was used in these calculations. The arrows indicate which direction a cloudtop feature at that location must be adjusted to account for parallax (i.e., towards the satellite sub-point). The displacements plotted are valid at the start (base) of the arrows.

It must be stressed that the length of the vectors plotted are extremely exaggerated to better show the displacement distance. Images shown are either near real-time images or colorized displacement distance images.

These images were made with McIDAS-X by Jim Nelson, CIMSS. Do not use these images for navigational purposes.

Thanks are extended to Tom Whittaker, Jordan Gerth and Scott Lindstrom for contributing to this work.