Choosing the Site

Selecting a site for the demonstration was actually a pretty difficult task, Johnson said. Unlike the U.S. or Canada, Tokyo has very few large parking lots or empty spaces that can be turned into a temporary track. The team also needed to find a space that wasn’t too far from the company’s office or the tradeshow, and that was actually available on demo day.

They spent a lot of time looking at Google satellite images of potential parking lots, Johnson said, trying to find valid options. Renesas shared the possible locations they’d spotted with Applications Engineer Bryan Leedham and his team at NovAtel before they traveled to Japan, and based on their recommendations were able to narrow the list even further. 

“We had two locations and both locations had issues that could generally cause problems with GPS,” Johnson said. “One was in a parking lot next to our building, which is tall, so signals being blocked by the building was a concern. The other site was under a bunch of trees, and also had a tall building on one side. There were definitely concerns GPS signals would not work in these locations.”

Renesas Car 3Leedham and the NovAtel team performed a traditional GNSS survey, assessing signal quality and tracking availability at both locations.

The ITK makes it possible to understand what’s going on in the GNSS spectrum in the environment in which GNSS is being operated, Leedham said, which wasn’t really available in the past. Traditionally, it required troubleshooting to determine why there was drifting or why you were having difficulty locking on, among other issues.

In Japan, NovAtel used the ITK to analyze the spectrum in the test sites. A spectrum analyzer that’s built into the receiver told the team what they needed to know about the L1, L2 and L5 GNSS bands—in real time, and without expensive spectrum analysis equipment.

During the surveys, Leedham did notice different types of interference at both sites, including a discrete spike popping in and out at 1600 MHz. Leedham measured the power level at different directions to get a better idea of what they were dealing with, and determined the interference was likely coming from a city-wide broadcasting signal.

Based on the information they received from NovAtel, Renesas selected the Tokyo Prince Hotel for the demo location. While Leedham found some interference was present, he wasn’t worried about it impacting the ProPak6 SPAN performance.