The GOES-R Geostationary Lightning Mapper (GLM) will provide valuable new earth-observation capabilities for real-time operational applications and research. The current GLM specification calls for 10-km resolution at nadir. The progressive foreshortening of earth features away from nadir, however, will reduce the instrument's effective resolution, increasing the lightning sensor's ground sample distance (GSD) to values of 20 to 30 km over many areas of interest, including much of CONUS. While the GLM lightning observations will still be valuable, the reduced resolution will be a limiting factor for some applications.

This presentation discusses a new class of optical devices that can be used to correct for the loss in image resolution due to angle of view and earth curvature effects. The optical adapters are a hardware modification that would have to be designed into new remote sensing instruments before launch. These adapters are particularly well-suited for use with the current GLM designs, and in most cases the functionality of the adapter could be incorporated into existing optical components.

With this enhancement, the GLM should be able to provide significantly higher resolution lightning position reports over CONUS (and other areas offset from nadir), while simultaneously providing uniform GSD observations across virtually the entire earth disk. With this approach, the nadir resolution requirement could be generalized into a single resolution requirement for the entire field of view.