Inside each van, duplicate hard drives record thousands of photos. Every day, drivers send one hard drive to Tele Atlas's office in New Hampshire to evaluate image quality and the other to a facility in Poland. There, employees use software to stitch a day's photos into a high-resolution mosaic that looks like an aerial image. The program also picks out every pattern that resembles a road sign, traffic light or other object. An editor categorizes the object and records its exact location in the database; that's how, for instance, your GPS knows the speed limit and how Google can show one-ways. Finally, the data goes to offices in New Hampshire and India to be converted into standard formats for customers such as Google, Pioneer and BMW, which then reformat it for their Web site or device.