Global Positioning System is a worldwide radio-navigation system formed from a constellation of 24 satellites and their ground stations. Even though GPS has gained immense popularity, its reception is still spotty indoors and in urban areas. As most GPS users already know, this is not the most reliable system when used indoors or in some urban areas. "Searching for Signal" or "Satellite Static" are some of the messages that urban GPS users are all too familiar with.

TV-GPS, developed by Rosum Corporation in Redwood City, California is a promising new technology that’s geared towards solving this problem. TV-GPS works by triangulating positions using television signals that are 2,000 times as strong as GPS satellite transmissions. With nearly 2,800 TV antennas concentrated mainly in U.S. metropolitan areas, where GPS coverage is weakest, TV-GPS has a ready-made infrastructure that can track Rosum’s patented chipset indoors, outdoors, in taxis, subways or any other city corner.

Rosum is working with GPS giant Trimble to get its chip in semi-trucks for fleet tracking. It can also be a useful tool that is portable and deployable for supporting first responder police, fire, and rescue personnel. Rosum is also working to provide technology and products to development partners and customers seeking solutions to location problems including People Tracking, Mobile Resource Management, Asset Tracking, Public and Personal Safety and Homeland Security.

Considering the fact that GPS devices are now in everything from cell phones to Hondas, a technology like TV-GPS is a great step forward in my opinion.  Efforts to make receivers smaller and more powerful have gotten so far, but the fact of the matter is terrestial broadcasts can give a much better return on investment for the cost of adding another low gain antenna.