AN INTRODUCTION TO COMMUNITY REMOTE SENSING

Remote sensing is a fundamental tool for understanding the world around us. Over the last several decades, we have come to depend on spacecraft and satellite systems for critical remotely-sensed information serving a variety of societal applications.

But we now face a dilemma. Society’s demand for information at diverse space and time scales grows rapidly, while the ability of our traditional sources to supply the information does not. Tomorrow’s applications will require work at a wide range of scales – global coverage with low refresh, high-resolution hyper-local, and more – with many problems spanning multiple scales. Renewable energy is a great example. Accurate knowledge of both long-term climate and near-term weather are required to optimize power generation, particularly in the wind and solar sectors.

Satellite and aircraft observing systems are struggling to address this ‘scale gap’. Such systems are ultimately limited by their cost and complexity. For the foreseeable future, budget realities will constrain the expansion of these centralized systems. Governments’ focus has shifted instead to ensuring current systems are used more efficiently through international collaborations such as GEOSS and public-private partnerships. To some extent, the private sector has stepped up with centralized remote sensing capabilities of its own, such as databases of street-level imagery from Google Street View and Bing Streetside.

An emerging field called community remote sensing (CRS), driven by the widespread availability of internet and mobile consumer technologies, may be our best means to fill the scale gap. CRS draws on the volunteer efforts of citizens and non-professionals to remotely sense and understand the world around them, and to augment our centralized systems with this knowledge.

Work similar to CRS has been done in the related areas of citizen science, citizen mapping, and e-science. But CRS itself encompasses novel techniques and skills that differ from these related disciplines. It is not just citizens taking pictures; the community can contribute to critical societal knowledge through calibration, validation, analysis, and many other activities that bring together the best of centralized and decentralized capabilities.

CRS will be a very exciting field as it evolves over the coming years.