The Design of a Resources Survey System

Orbital survey offers great promise for the location and evaluation of the Earth´s resources. To exploit that potential operationally, a system must be designed from the ground phenomena through the spacecraft and data handling to the satisfaction of user requirements. The first step planned by NASA involves the Earth resources technology satellite (ERTS); as a prototype of an operational system, the alternative concept developed here takes a significantly different form. The resources survey system (RSS) produces optical-spectrum imagery of the continental United States with both photometric and photogrammetric fidelity. The data volume is determined, and the ground processing requirements developed into a conceptual system fully loading a second-generation computer. To achieve a manageable ground system, the use of a line scanner is required; the characteristics of the sensor dictate a small spacecraft adapted to Scout or piggyback launch. Extension of the system to allow automatic signature recognition and incorporation of aircraft and ground-truth is straightforward. RSS is therefore a prototype in the sense that its limited performance can evolve without basic redesign into any foreseeable system, and operational in that its output is immediately and routinely usable both in its form and in its content.