RTK From the Sky Brings Instant GNSS Accuracy Worldwide; PPP Has Become RTK - Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design

RTK From the Sky Brings Instant GNSS Accuracy Worldwide; PPP Has Become RTK

The latest release from Hexagon promises precise point positioning (PPP) convergence in less than a minute for centimeter-level accuracy on land, air and marine applications around the world. This effectively combines the complementary benefits of real-time kinematic (RTK) with PPP: rapid accuracy everywhere, without base stations. It establishes a foundation for assured positioning with no downtime in marine, agriculture, and autonomous applications.

Research from Hexagon’s Autonomy & Positioning division has produced a PPP breakthrough that enables nearly instant global centimeter-level accuracy, according to the company. These developments pave the way to bring “RTK From the Sky” performance to worldwide users through correction service products and GNSS receivers from Hexagon.

“RTK From the Sky” technology provides the quick accuracy of an RTK solution with the high accessibility and availability of PPP. Users will no longer have geographic or regional infrastructure restrictions. They will be free to operate anywhere around the world with the same premium level of positioning performance. “RTK From the Sky” technology removes the traditional PPP barrier of long convergence times as well as Internet and radio communication limitations, delivering instantaneous convergence anywhere in the world.

RTK from Sky examples
Horizontal position error (95%) after a PPP reset. Based on one week of data reset every 10 minutes (over 1,000 resets). Courtesy Hexagon | NovAtel.

Achieving these results requires attention to detail throughout the positioning ecosystem: no errors cancelled and no errors ignored. All errors are carefully estimated and removed from the final GNSS position quickly and reliably, Hexagon stated. The end-to-end fine-tuning of measurement quality and error mitigation establishes the foundation for “RTK From the Sky” performance. No matter the location or application, the company promises that users will be able to rely upon the highest availability and accuracy of corrections anywhere in the world, without the convergence time.

The first step in developing the new product was establishing, securing and error-proofing a global reference station network, fine-tuning each station’s antennas, receiver hardware and firmware. In addition to tracking all GNSS constellations’ broadcast frequencies, the system applies advanced anti-spoofing, multipath mitigation and integrity monitoring algorithms.

The correction generation software transforms the MCMF data into a robust, reliable set of corrections valid or worldwide use and delivers them with low latency over L-band satellites and Internet protocol (IP). NovAtel receivers and firmware are optimized to use this data quickly and accurately.

RTK from Sky consistency
Distribution of convergence time or 21 stations distributed around the world over 4 weeks (84 days of data with over 1,000 resets each). courtesy Hexagon | NovAtel.

“In 2020, PPP has become RTK – without the mobility limitations,” said Sandy Kennedy, VP of Innovation at Hexagon’s Autonomy & Positioning division. “‘RTK From the Sky’ has been a very satisfying development. To see this kind of positioning performance available anywhere in the world is the realization of the next step of innovation for GNSS.”

“RTK From the Sky” technology will be the foundation for future correction service products and applications from Hexagon built for diverse applications. For more information, read Hexagon’s white paper here. “PPP has become RTK,” it asserts.