Precise Point Positioning
The enhanced OEM7 GNSS technology also comes with a variety of other features that NovAtel customers both want and need. Beyond the additional frequencies and signals, the receivers also come equipped with L-Band functionality. This enables satellite delivery of PPP correction data and allows for centimetre level positioning, even in the most complex environments, without the need for a Real-Time Kinematic (RTK) base station network, Gerein said. These types of correction services have become more robust over the years and are vital to customers in many of the new markets that NovAtel now serves.
NovAtel uses GNSS satellite clock and orbit correction data from TerraStar for its PPP services. TerraStar operates 80 ground reference stations located, around the world, with triple redundancies and uplinks to satellites so users anywhere on the planet can see at least two satellite beams, according to Gerein. “This enhances the number of places our customers can get centimetre level accuracy.”
The Interference Toolkit
One of the most important additions to NovAtel’s new OEM series is the Interference Toolkit, which can detect interference and jamming and then mitigate that interference and jamming with filters, a particularly useful feature for system integrators.
This feature is in response to the frequency spectrum getting more crowded with intentional and unintentional GNSS interference, Hamilton said. NovAtel is taking that problem on for the customer, and anticipates this becoming an even bigger problem in the future.
“We’re starting to see either unintentional or intentional jamming wiping out GPS in localized areas,” Hamilton said. “If you’re relying on GNSS to control a vehicle, it’s pretty dangerous when it cuts out. We need to make these systems as robust as we can in the face of that interference.”
When customers integrate a NovAtel receiver into another system, the OEM7 has to work in close proximity with other things inside the customer’s system such as other power supplies and other electronic circuitry, Gerein said. As GNSS signal processing moves into that more complex electronic environment, the receiver may encounter a harmonic signal that shows up as interference.
“Although they don’t anticipate that in the design, when they begin to work in the lab to complete the integration they might see that interference,” Gerein said.
Finding the source of the interference becomes a trial-and-error process in the system integrator’s lab, and the customer has to use resources to debug the problem. That can take a lot of time.
“The OEM7 Interference Toolkit has a spectrum analysis function the integrator can turn on to see which GNSS frequency is experiencing interference,” said Gerein. “They can say ‘Hey, I see the interference in this band,’ and then they can narrow in on the frequency.”
The Interference Toolkit can detect self-interference (electromagnetic interference or EMI) from other components in a product or system. It enables integrators to look at the spectrum to confirm that a problem exists, determine where it’s coming from, implement the filter to get rid of the interference and continue with the mission.
Not only does this feature save engineers and technicians the time and money it takes to find the source of the interference, Gerein said, it also gives them the opportunity to set up a filter during the design stage. This negates the need to add an external cavity filter later, which can also be expensive.
“They can modify the design, or, if it’s a case where the interference is coming from the outside world, they can add a digital filter, which will remove the interference,” Gerein said. “So for customers who use a cavity filter, which is usually a large expensive Radio Frequency or (RF) filter, they can set up a filter at design time instead.”
The Interference Toolkit also offers a huge advantage when customers are out in the field, Gerein said. Often, integrators will notice they’re not receiving GNSS any more or that the signal is degraded—which can be a problem if they’re trying to perform a field trial at one of their customer’s locations. Typically when this happens they have to bring the GNSS equipment back to the lab for analysis, which of course leads to frustration and wasted time. With the Interference Toolkit, they can fix the problem on the spot.
“System integrators work in multiple locations. If they get to a location and they’re trying to do a job and can’t complete a job because of signal interference, that’s when this feature becomes important,” Gerein said. “If you can mitigate against interference you can complete your job. It makes the receivers more robust while out in the field.”
OEM7 receivers are also available in smaller form factor cards for customers with size constraints,
Gerein said, and come with flexible configuration options for seamless integration. All product documentation is now online, which also helps make integration easy.
“There’s a much more user friendly documentation suite that comes with OEM7 products,” Hamilton said. “That means integrators have an easier time integrating the product into their application.”
New integration guides also make it easy to upgrade from the OEM6 to OEM7, Gerein said.
“Ease of integration is the real key there,” Gerein said. “NovAtel is willing to work closely with customers to ensure seamless, quick integration so they can realize their return on investment as soon as possible.”
Each receiver can be used with NovAtel SPAN®, Gerein said, which couples the company’s OEM precision GNSS receivers with robust Inertial Measurement Units (IMUs) for reliable, continuously available position, velocity and attitude—even when satellite signals are temporarily unavailable. SPAN technology has been used in many of the markets
NovAtel serves and helps with the integration of GNSS Plus.
Past generations of the receiver used a command line interface or PC application to configure the receiver and collect data from it. With the OEM7, a new interface has been added that allows users to configure the receiver and collect data using a Web browser.