The Multiangle Imaging SpectroRadiometer (MISR) is currently under dev
elopment for NASA's Earth Observing System. The instrument consists of
nine pushbroom cameras, each with four spectral bands in the visible
and near-infrared. The cameras point in different view directions to p
rovide measurements from nadir to highly oblique view angles in the al
ong-track plane. Multiple view-angle observations provide a unique res
ource for studies of clouds, aerosols, and the surface. MISR is built
to challenging radiometric and geometric performance specifications. R
adiometric accuracy, for example, must be within +/-3%/1 sigma, and po
larization insensitivity must be better than +/-1%. An onboard calibra
tor (OBC) provides monthly updates to the instrument gain coefficients
. Spectralon diffuse panels are used within the OBC to provide a unifo
rm target for the cameras to view. The absolute radiometric scale is e
stablished both preflight and in orbit through the use of detector sta
ndards. During the mission, ground data processing to accomplish radio
metric calibration, geometric rectification and registration of the ni
ne view-angle imagery, and geophysical retrievals will proceed in an a
utomated fashion. A global dataset is produced every 9 days. This pape
r details the preflight characterization of the MISR instrument, the d
esign of the OBC, and the radiance product processing.