From November 12-17, 2021, the Landsat 8 and Landsat 9 satellites engaged in an underfly exercise that allowed for a unique calibration opportunity at the start of the Landsat 9 on-orbit mission. Early in the mission, Landsat 9 drifted in its orbit, and allowed for the near-coincident collection of data with Landsat 8. This near-coincident image acquisition decreased the temporal changes between data acquired by the two satellites. Toward the end of the underfly event, the Landsat 9 spacecraft pointed off-nadir during several descending passes to increase overlap between the two satellites images. This new publication highlights the geometric accuracy between the Operational Land Imager (OLI) onboard both satellites, using tandem collects from the underfly exercise.

The authors found that the co-registration between Landsat 8 and Landsat 9 data are within 2.2 meters across all bands with at least 10 percent overlap, contain less than 20 percent cloud cover, and include at least 50 percent land. The 2.2 meters represents less than one-tenth of a 30-meter multispectral pixel in misregistration between the Landsat 9 and Landsat 8 underfly products.  

Reference: Choate, M.J., Rengarajan, R., Storey, J.C., Lubke, M. Landsat 9 Geometric Characteristics Using Underfly Data. Remote Sens. 2022, 14, 3781.  https://pubs.usgs.gov/publication/70236633