IKONOS data from Space Imaging
The IKONOS images, made available through NASA's former Scientific Data Purchase Program (SDP), are roughly 11km x 11km scenes of 1-meter (panchromatic) and 4-meter (multispectral) images. The SDP allocation had been established with an aim to acquire at least one IKONOS image for each site. The tasking of these scenes was based on the timing of field campaigns and the availability of tower and/or additional field instrumentation.
For further information on IKONOS, see the Earth Observation Magazine article: Demystification of IKONOS, by Dr. Thier Toutin and Dr. Philip Cheng.