High Resolution Mapping with Small Satellites

Civil space-borne Earth surface mapping started in 1972 with a 80 m GSD provided by ERTS, later renamed to Landsat-1. Nowadays, the GSD approaches 1 m or even less. This trend was supported by the improvements in divers fields of technology as for instance optics, mechanics and materials, electronics, signal Optical Information Systems processing, communications and navigation. The space-borne mapping systems always attempted to achieve the highest ground resolution possible with the available technology at the given time. Also mass, volume and power consumption of the spacecrafts and instruments followed the trend to miniaturization. SAR systems are an alternative to passive optical systems; they also benefit from the technology improvements. But the most promising prospects for high resolution mapping with small satellites are connected with passive optical systems, especially push-broom systems. The paper tries to analyse how far can we go in decreasing the GSD using instruments and spacecrafts decreasing in size, mass, and power consumption. In this context the paper deals with important parameters for mapping with small satellites as spatial resolution, radiometry, mass, volume, power consumption, microelectronics, pointing accuracy and stability, data volume and transmission. From the viewpoint of technology, space-borne mapping systems using small satellites are feasible. It is a question of market requirement and market behaviour whether or not these small satellite-based mapping systems can compete with the existing mapping systems, space-borne or airborne.