Streetcar Sensors

Starting this summer, the Atlanta Streetcar began using a real-time dispatching method developed at Georgia Tech that eliminates the need for schedules and cuts down on passenger wait times. School of Civil and Environmental Engineering Assistant Professor Kari Watkins and Ph.D. student Simon Berrebi developed an algorithm that ensures each vehicle is spaced evenly along the 2.7-mile route in downtown Atlanta, maximizing the frequency of service. Unlike the previous method, the Georgia Tech algorithm uses real-time information.

One problem the researchers faced was the "urban canyon" effect where the GPS reception reverberates on buildings or is blocked entirely, creating an error in the signal and causing the apparent GPS location of the vehicles to wander. Watkins and Berrebi worked with Research Scientist Bill Eason of IPaT and the Georgia Tech Research Network Operations Center (GT-RNOC), and GT-RNOC Co-director Russ Clark to use a barometric pressure sensor. They found that the newest sensors, designed to be built into next-generation cell phones, are sensitive enough to detect changes in elevation of under a meter (3.3 feet). The sensor measures changes in elevation and allows for more accuracy in pinpointing the location of a streetcar in real-time.

Matt Sanders, Russ Clark
Siva Jayaraman, Sean Donovan

The Georgia Tech Research Network Operations Center (GT-RNOC) exists to accelerate innovation in networking, computing, mobility and convergence by enabling communities of collaboration. GT-RNOC provides, supports and maintains a unique end-to-end infrastructure within a realistic operational setting, accessible to world class students, researchers and innovators from various disciplines across the many Georgia Tech research centers.

GT-RNOC leverages the unique position of Georgia Tech as a pre-eminent network and network service hub in the state, the region and increasingly in the world. It provides researchers with access to this unique network infrastructure. It provides network administrators and service providers with an invaluable tool for developing and testing new management solutions in a cutting edge environment. Industry members of GT-RNOC include leaders in wireless, telecom, and cable, plus equipment, application, and content providers.