Concept | Technology | Research Team

Plan

... to create a computerized procedure for deriving population and housing estimates of user defined areas based on current, remotely sensed data.

The system will be of strategic importance to a wide range of commercial interests seeking "up-to-the-minute" counts and measures of population and housing change for purposes including site location and precise estimates of market size.

A procedure to transform both aerial photography and low cost, high resolution satellite imagery by combining image processing technology and demographic estimation techniques will make it feasible to provide monthly population estimates for any user-defined area in the United States or Canada, and, eventually, the world. The project's key innovation involves the unique combination of image processing technology, demographic estimation techniques, and remotely sensed data resulting in a radically new and more robust, empirically-based method for obtaining current population estimates. Since the majority of commercially available population estimates are based either on often outdated administrative records and symptomatic indicators or on presumptive mathematical procedures, any process that can generate estimates from empirically-based, current housing unit counts will have enormous commercial potential.

Background

The notion of using remotely sensed data to identify housing structures for population work has existed for well over a half-century when, in the 1940's, the U.S. Census Bureau explored the feasibility of using aerial photography to locate housing in remote rural areas to reduce the decennial census undercount. In the last two decades, a number of research efforts have explored the feasibility of using remotely sensed data to obtain population estimates. While these efforts have shown promise, they have lacked the necessary precision to be useful in the commercial sector. There are three reasons these efforts have met with only limited success: 1) most have lacked high resolution imagery, 2) critical pixel-level information has been unavailable, and 3) sophisticated pattern recognition software has only recently become available. These limits are being lifted as a result of soon-to-be-available high resolution stereoscopic satellite imagery, the availability of automatic, every-pixel, elevation extraction software, and sophisticated image processing pattern recognition packages capable of classifying spatial attributes of the urban landscape.

Benefits

Traditional estimation methods exhibit high levels of accuracy; however, they have persistent shortcomings that can only be resolved by directly linking methods with substantive socio-economic and demographic dynamics. There are two major benefits of a satellite-based system over existing methods of population estimation. A major benefit of satellite-based, spatially explicit data is in providing just such a linkage, yielding not only improved accuracy, but also a basis from which population estimates can be understood and explained in terms of their underlying substantive dynamics, an important feature for end-users. The second major benefit is to be found in the high frequency with which estimates can be updated. The EarlyBird satellite, for instance, circles the earth every 94 minutes, revisiting locations every 36 to 120 hours, depending on latitude. No existing population estimate system offers a data collection process that allows for such a high update frequency.