Now that the Nomad rugged handheld is shipping, we’ve started getting some questions about its integrated GPS. The first thing to know about the GPS is that it’s based on the standard SiRF Star III chipset. As a consumer-grade GPS device, I wouldn’t expect to get mapping or survey-grade results. However, SiRF Start III-based devices have a reputation for tracking accurately in difficult conditions. In order to get user’s feel for the Nomad, I took one on a hike recently to see how it tracks under tree cover. I installed TDS TerraGuide (available for the Nomad) as the mapping application and configured it to connect to COM2 at 9600 baud (the default settings on the Nomad). For my test, I turned the unit on in an open area to get a good initial fix before starting my hike. As with any GPS device, getting a first fix in an open area is always faster and more accurate than getting one under tree cover.
I was impressed with the Nomad GPS performance under these difficult conditions. The unit tracked 6 to 7 satellites on a heavily canopied forest road. The map below shows a track updated every second on the mapping program. In most cases, even under trees, the Nomad tracked directly on top of the USGS map.