CAREER/EPSCoR: Geospatial Database-Driven Extraction of Information from Digital Aerial Imagery

This project aims at the advancement of the ability to extract spatial information from digital aerial imagery by taking advantage of geospatial databases to support and guide object extraction operations. It deals with aerial images representing scenes for which prior or complementary information already exists. Examples of such information are pre-existing digital maps, digital terrain models, and spatial information systems in general. The research plan involves: (1) matching images to existing databases for change detection; (2) analysis of scale differences between database information and image; and (3) developing metadata structures to convey accuracy information for objects contained in geospatial databases. By embedding object extraction processes within the framework of spatial information systems, digital image analysis will be able to exploit the advantages offered by the availability of spatial data from various sources and in diverse formats, and, in turn, contribute to the improvement of the temporal and quantitative quality and completeness of the data contained in those sources. The educational aspect of the project includes initiatives designed to take advantage of and incorporate the project research advancements in the graduate and undergraduate curriculum, as well as in the high-school outreach program of the Department of Spatial Information Engineering. A 3-day workshop, with participation of U.S. and international experts is also planned. Combined, the issues addressed in this project will substantially advance science in digital image processing and analysis, and will complement parallel advancements in a variety of related disciplines, most notably digital libraries, geographic information systems, and remote sensor technology

Digital Government: Knowledge Management Over Time-Varying Geospatial Datasets

Spatially-related data is collected by many government agencies in various formats and for various uses. This project seeks to facilitate the integration of these data, thus providing new uses. This will require the development of a knowledge management framework to provide syntax, context, and semantics, as well as exploring the introduction of time-varying data into the framework. Education and outreach will be part of the project through the development of an on-line short courses related to data integration in the area of geographical information systems. The grantees will be working with government partners (National Imagery and Mapping Agency, the National Agricultural Statistics Service, and the US Army Topographic Engineering Center), as well as an industrial organization, Base Systems, and the non-profit OpenGIS Consortium, which works closely with vendors of GIS products

ITR/IM: Enabling the Creation and Use of GeoGrids for Next Generation Geospatial Information

The objective of this project is to advance science in information management, focusing in particular on geospatial information. It addresses the development of concepts, algorithms, and system architectures to enable users on a grid to query, analyze, and contribute to multivariate, quality-aware geospatial information. The approach consists of three complementary research areas: (1) establishing a statistical framework for assessing geospatial data quality; (2) developing uncertainty-based query processing capabilities; and (3) supporting the development of space- and accuracy-aware adaptive systems for geospatial datasets. The results of this project will support the extension of the concept of the computational grid to facilitate ubiquitous access, interaction, and contributions of quality-aware next generation geospatial information. By developing novel query processes as well as quality and similarity metrics the project aims to enable the integration and use of large collections of disperse information of varying quality and accuracy. This supports the evolution of a novel geocomputational paradigm, moving away from current standards-driven approaches to an inclusive, adaptive system, with example potential applications in mobile computing, bioinformatics, and geographic information systems. This experimental research is linked to educational activities in three different academic programs among the three participating sites. The outreach activities of this project include collaboration with U.S. federal agencies involved in geospatial data collection, an international partner (Brazil\u27s National Institute for Space Research), and the organization of a 2-day workshop with the participation of U.S. and international experts

Coastal Change and Beach Ridges along the Northwest Coast of Peru: Image and GIS Analysisof the Chira, Piura, and Colán Beach-Ridge Plains

Since approximately 5200 cal yrs BP, five sets of eight to nine beach ridges were built and preserved along the northwestern Peruvian coastal desert (3o30\u27S-9oS). Potential ridge-building mechanisms in the hyper-arid environment of northwest Peru include El Nifio floods and storms, seismic activity, and sea-level change, as well as more gradualc limate changes that affectedc oastal morphologyI. mage processinga nd GeographicI nformationS ystem (GIS) methods were used to analyze aerial photographs and measure historic coastal patterns along three beach-ridge plains over a 37-year time period. Coastal features were digitized from image mosaics of each ridge plain at different time intervals from 1946 up to 1983. Progradation rates were examined at ridge locations north of the Chira River and Piura River, as well as at the base of ephemeral stream valleys in Colin. The total change in beach area was measured from historic aerial photographs taken at different time intervals. The resulting measurements showed that sediment distributed by El Nifio storms was redeposited along the shoreline within a few years following each event. The difference between the frequency of El Nifio events (currently 2-7 years) and the rate of ridge preservation (1 per 500 years average) suggests that individual ridges may be composites of multiple depositional events, or that ridges result from the rare convergence of multiple processes and conditions. A change in style of ridge formation in all studied beach-ridge sets correlates with, and may be explained by, change in the frequency of El Nifio events at about 3000 cal yrs BP

ACCURACY-AWARE CHANGE DETECTION IN SPATIAL WEBS A Position Paper

Change detection is a fundamental operation in Spatial Webs, as it is essential for geospatial database updating, conflation, and redundancy management. Considering image-based change detection in particular, current practices typically use complex algorithms (e.g. snakes, template matching) to identify and automatically extract objects in a new image. Following object extraction, a GIS database is updated by comparing the newly extracted outline to the stored prior information. Usually, if the new outline is different, the older information is replaced by it, and the database is thus updated. In this context, information is treated as deterministic in nature: any difference between two outlines is considered as change. When the two datasets compared differ in their properties (e.g. resolution, scale, accuracy) this process would result into frequent false positives: change would be detected even though the object under examination has actually remained unchanged. Given the diverse nature of datasets in Spatial Webs, this deterministic approach to change detection is clearly inadequate, forcing us to consider accuracy-aware approaches. Addressing this problem from an image analysis point of view, we have developed a novel automated approach that integrates object extraction and change detection into a single process by using accuracy information. Our approach is meant to function within an integrated geospatial environment, whereb

Differential Snakes for Change Detection in Road Segments

Suetens et al. (1992), Gruen et al. (1995b), Gruen et al. (1997), The automation of object extraction from digital imagery has and Lukes (1998)