Experimenting with sensor Webs using Earth Observing 1

The New Millennium Program (NMP) Earth Observing 1 (EO-1) satellite was launched November 21, 2000 as a one year technology validation mission. After an almost flawless first year of operations, EO-1 continued to operate in a test bed mode to validate additional technologies and concepts that will be applicable to future sensor Webs. A sensor Web is a group of sensors, whether space-based, ground-based or airplane-based which act in a collaborative autonomous manner to produce more value than would otherwise result from the individual observations. Interestingly, it seems that the trend at this time is to link a set of heterogeneous satellites and instruments together in an "ad hoc" constellation for a limited period of time to get new science products. In our experiments, we used the MODIS instruments on Aqua and Terra to locate terrestrial events such as forest fires and then to trigger high-resolution images of targeted events with either the advance land imager (ALI) or Hyperion on EO-1. To achieve this, we created a variety of software on the spacecraft and on the ground to coordinate the planning and triggering of these images. Furthermore, it became clear from the lessons learned that future sensor Webs are going to need some key capabilities to enable progressive autonomy and sufficient reuse to make these constellation cost effective for science. This paper describes the experiments, the lessons learned and the implications for future sensor Webs.