TerraServer-USA Sponsors

TerraServer-USA database and web site are made possible by the contributions of the following organizations:

		The TerraServer-USA is maintained and managed by the Microsoft MapPoint organization with MSN. TerraServer-USA became a component of the MSN Virtual Earth suite of products as of July 25, 2005. TerraServer-USA was originally developed by Microsoft Research as a scalability demonstration of Microsoft SQL Server 7.0. The web site was first launched in June 1998 running on Windows NT 4.0, SQL Server 7.0 Beta 2, and a DEC AlphaServer. Since then, the site has evolved to being one of the major geo-spatial sites on the world-wide web. The TerraServer-USA web application is written in C# and hosted within the ASP.NET web environment. ASP.NET web pages access T-SQL stored procedures via ADO.NET. Originally, two load programs were written in C and using ODBC APIs to process input imagery, compress it, insert it into the SQL database, and create an image pyramid (zoomed out imagery). In 2004, we have begun a re-write of the load and administration programs from C to C#, Windows Forms, and the use of the .NET Framework libraries. The new load program runs on-line with the web application. Approximately 10 GB of compressed data is loaded daily.
		The US Geological Survey provided the Digital Ortho Quadrangle (DOQ) aerial imagery data and the Digital Raster Graphics (DRG) topographical map data to the project. To date, the USGS has provided 950 CDROMs containing 530 GB of compressed topographical map data and 720+ DLT tapes (Digital Linear Tape) containing 16 TB of uncompressed aerial imagery. The USGS DOQ program has completed with approximately 96% coverage of the conterminous United States. Beginning the fall of 2003, the USGS began delivering a new, natural color data-set known as "UrbanArea" data. This data-set is 1 foot resolution data and will cover approximately 133 major U.S. cities when it is complete. To date (May 2004), we have received approximately 6 tera-bytes of imagery covering 35 cities. At this time, there the completion date has not been announced.
		All the imagery and meta-data displayed on the TerraServer web site is stored in Microsoft SQL Server databases. The current design, deployed in November 2003, uses a "scale-out" design where we deploy a logical "bunch" of database servers that contain one copy of all the imagery and meta-data. For redundancy and availability, we deploy two indentical "bunchs" of database servers. Previously, TerraServer focused on "scale-up" by partitioning the imagery data across three SQL Server 2000 1.5 TB databases. USGS aerial imagery is partitioned across two 1.5 TB databases. The USGS topographical data is stored in a single 1.5 TB database. Each database server ran on a separate, active server in the four-node Windows 2000 Datacenter Server cluster. Should a database processor fail, any node in the Windows 2000 Datacenter Server cluster can attach and host the SQL Server 2000 database from the failed server. Conceivably all three databases could failover to a single server.

Emeritus Sponsors

TerraServer-USA, previously known as Microsoft.TerraServer.com, has been available on the internet since June 1998. A number of organizations have been major contributors and very generous to TerraServer over the years. We acknowledge and very much appreciate the contributions of the following organizations:

		TerraServer-USA ran exclusively on HP servers and storage arrays from June 1998 when the web launched as TerraServer.Microsoft.com through November 2003. Hewlett-Packard Corporation donated the 4 HP ProLiant 8500 database servers. The disk storage equipment, 18.0 TB in total, was donated by the StorageWorks division of Hewlett-Packard Company. The web servers are eight HP ProLiant DL360, "1u" processors.
		Advanced Digital Information Corporation (ADIC) provided a Scalar 1000 configured with four LTO tape drives. LTO tape technology is capable of storing 100 GB to 200 GB of data per magnetic tape depending on the amount of compression. Thus 5 to 10 tapes are required to backup a single tera-byte of data. We retired the Scalar 1000 tape library in November 2003 after 3 years of flawless operation.
		The TerraServer SQL databases are regularly backed while delivering service to internet users (online backup). The SQL Server Backup utility performs the tasks required to read the appropriate database pages into memory. Veritas NetBackup, a leading Enterprise backup utility, integrates with SQL Backup utilities to manage the ADIC Scalar 1000 tape robot and the tape inventory. The backup operation is remotely managed from our Redmond offices, 30 miles away from the Internet Data Center. We discontinued using Veritas NetBackup at the same time we retired the ADIC Scalar 1000 tape library.
		From September 2000 through May 2003, Terraserver-USA was powered completely Extreme Network Switches. Extreme Networks provided Summit 7i's because Terraserver required a fast and powerful, yet compact switching solution at the core of their network. Each Summit 7i provides a full wire speed, non-blocking hardware architecture, as well a very rich array of embedded features including full routing capabilities, server load balancing, and bi-directional rate limiting. Extreme's Summit 7i helps Terraserver provide guaranteed networking uptime of this site. In June 2003, TerraServer-USA moved to a new data center and connected to the MSN internet networking infrastructure.