The NPOESS Preparatory Project Science Data Segment: Brief Overview. - Robert J. Schweiss; Evelyn L. Ho; Richard E. Ullman; Shahin Samadi (IGARSS, 2006)

The NPOESS Preparatory Project Science Data Segment (SDS) Data Depository and Distribution Element (SD3E) System Architecture. - Evelyn L. Ho; Robert J. Schweiss (IGARSS (4), 2008)