The primary payload of the OrbView-1 spacecraft is the OTD (Optical Transient Detector), a lightning instrument package provided by NASA/MSFC. The secondary payload on OrbView-1 is GPS/MET (GPS/Meteorology), an instrument provided by UCAR (University Consortium for Atmospheric Research, with collaboration by JPL, Stanford University, and the University of Arizona) which uses GPS signals to measure Earth atmospheric properties. Science data processing of OTD and GPS/MET is done at MSFC and UCAR, respectively.