Frank P. McCreedy

Enhancing the US Navy's GIDB Portal with Web Services

Using Web services, the authors have been able to increase the amount of data accessible through the Naval Research Laboratorys geospatial information database (GIDB) portal. They created a Web crawler for Web mapping services (WMS) that harvests and adds data to the portal index and a translator that provides access to non-WMS data through the WMS interface. The integrated Web services broker, using traditional Web services standards, provides automated access to meteorological and oceanographic data

A system to distribute Navy Coastal Ocean Model data using the open Geospatial consortium's Web Map Service protocol

A method for disseminating Navy Ocean Coastal Model (NCOM) data as imagery over the Internet via the Web Map Service (WMS) protocol is presented. NCOM data are provided in multidimensional numerical data files. Distribution of NCOM data via the WMS protocol requires the data be rendered into an image. The multidimensional properties of the NCOM data allow the plotted data images to be grouped into layers based on dimensions. The NCOM WMS supports optional functionalities provided by the WMS protocol, allowing users to obtain detailed information about map images created by the NCOM WMS. By serving NCOM data via the WMS protocol, clients can access the data using common geographic information system (GIS) client software.

Active network architecture and management

Access and retrieval of meteorological and oceanographic data from heterogeneous sources in a distributed system presents many issues. There are a number of features of the TEDServices system that illustrate active network management for such data. There is a self‐aware or intelligent aspect with respect to the mechanisms for shutdown, data ordering, and propagation of data orders. Intelligent cache management and collaborative application sharing process are other features of the active network management. Additionally a very important capability is the implementation of resumable object streams, which allows either the client or server side of a request to lose network connection, regain it, and the request will continue where it left off.

A Framework for Databasing 3D Synthetic Environment Data

Since 1994 the Digital Mapping, Charting and Geodesy Analysis Program at the Naval Research Laboratory has been developing an object-oriented spatial and temporal database, the Geographic Information Database (GIDB™). Recently, we have expanded our research in the spatial database area to include three-dimensional synthetic environment (3D SE) data. This work has focused on investigating an extension to the National Imagery and Mapping Agencys (NIMAs) current Vector Product Format (VPF) known as VPF+. This paper overviews the GIDB and describes the data structures of VPF+ and a prototyped 3D synthetic environment using VPF+. The latter was designed as a 3D Geographic Information System (3D-GIS) that would assist the U.S. Marine Corps with mission preparation and also provide onsite awareness in urban areas.

Reduced memory JPEG decompression for mobile devices

Imagery makes up a large percentage of geospatial data in use today. One feature of this imagery is that it tends to be large, often hundreds or thousands of megabytes. As a result JPEG compression is often used to make geospatial imagery manageable by reducing the file size without greatly reducing the quality of the image. However, the benefits of compression are absent when the image must be viewed. Viewing a large JPEG image requires decompressing and holding the uncompressed version in memory. Holding the entirety of a large image in memory is a burden on many systems and sometimes impossible. However, the entire image is rarely needed at full resolution. Usually only a small area of interest is viewed or processed. This paper describes a method of removing a small area of interest from a large JPEG without decompressing the entire image. JPEG compressed images are streams which cannot be randomly accessed. Viewing a particular area requires that all preceding areas be partially decompressed. This process is more efficient than fully decompressing the whole JPEG, but depending on the area requested the entire image may need to be partially decompressed. To circumvent this problem an index file is created on first decompression which records markers for the sections of the JPEG. The index file allows random access to the JPEG file so that areas may be decompressed without reading the preceding portions of the JPEG. This method of decompressing a JPEG requires a limited amount of memory and with an index file is fast enough to be performed in real time.

Searching and exploitation of distributed geospatial data sources via the Naval Research Lab's Geospatial Information Database (GIDB) Portal System

The Naval Research Laboratory’s Geospatial Information Database (GIDBTM) Portal System has been extended to now include an extensive geospatial search functionality. The GIDB Portal System interconnects over 600 distributed geospatial data sources via the Internet with a thick client, thin client and a PDA client. As the GIDB Portal System has rapidly grown over the last two years (adding hundreds of geospatial sources), the obvious requirement has arisen to more effectively mine the interconnected sources in near real-time. How the GIDB Search addresses this issue is the prime focus of this paper.

The National Guard Bureau's Digital Mapping System Portal System

The National Guard Bureau (NGB) and the Naval Research Lab (NRL) have developed a Digital Mapping System (DMS) Portal System that currently connects over 360 geospatial data servers. The DMS Portal System is located at http://ngbcdmaps.gtri.gatech.edu and is being used by nationwide law enforcement (approximately 5000 users/month) to generate geospatial mapping solutions to satisfy broad requirements with no licensing required. This paper will highlight the current functionality of the DMS Portal System to allow many types of geospatial information (such as weather, conventional maps, imagery, plume model dispersions, etc.) to appear in a common environment regardless of how the information is originally stored. The DMS Portal System has substantial potential usage in the homeland defense arena as well as with conventional DoD/government and private sector users. Future directions for this cutting-edge technology will be outlined.

Efficient Storage of Large Volume Spatial and Temporal Point-Data in an Object-Oriented Database

Data mining applications must deal with large volumes of data. In particular, Spatio-Temporal Information Systems must efficiently store and access potentially very large quantities of spatial and temporal data. Therefore, storing the data in an efficient and useful way is of great importance. Binary Large Objects (BLOBs) are found in many database systems and have been extensively used in typical database applications for the storage of large volume data. In this chapter, we describe the extension of basic BLOBs for specialized use with spatial and temporal data. These new repositories, Spatial BLOBs and Temporal BLOBs, add additional functionality for the query and retrieval of the repository’s contents in a semantically meaningful, object-oriented form. The repositories are designed as flexible frameworks, decoupled from the particular binary format of their internal contents. Custom plug-ins allow the frameworks to be extended to use a particular binary format that is most appropriate for a given data type.