During the underfly, several African sites were imaged near-coincidentally by ETM+ and OLI. Among these underfly scenes were paths 182 rows 42 and 43 and path 198 rows 38 and 39 where simultaneous or near simultaneous Hyperion data were also collected. The Hyperion data provide an opportunity to account for the spectral band differences as described earlier and provides an alternative to simultaneous ground measurement which is often impossible for remote inaccessible areas. The rationale behind using near simultaneous image pairs for cross calibration is to reduce the uncertainties that may arise due to uncharacterized atmospheric conditions between overpass times. Landsat-7 ETM+ and Landsat-8 OLI images of these sites were collected within 4 minutes of each other