Aggregation of Hyperion hyperspectral spectral bands into Landsat-&ETM+ spectral bands

The Landsat 7 ETM+ spectral bands centered at 479 nm, 561 nm, 661 nm and 834 mn (Bands 1, 2, 3, and 4) fall nicely across the Hyperion VNIR hyperspectral response region. They have bandwidths of 67 nm, 78 nm, 60 nm and 120 nm, respectively. The Hyperion spectral bandwidth of 10.2 nm results in 10 to 15 Hyperion spectral samples across each Landsat band in the VNIR. When the Hyperion spectral responses in the 10.2 nm bands are properly weighted to aggregate to a given Landsat band, the radiometric response of the Landsat band can be reproduced by Hyperion. This is done for Bands 2, 3 and 4 on the scene 7 of Lake Frome, Australia collected simultaneously by Hyperion and Landsat on January 21, 2001. The initial comparison of the radiances from Hyperion synthesized into the ETM+ bands with the Landsat-7 ETM+ radiances showed differences of 15-23%, with ETM+ being higher. Prior to launch a laboratory standard comparison showed differences of 10-13% in the same direction.