What advances have you observed across the GNSS field in recent years? How has Trimble adapted its services accordingly?
Akshay Bandiwdekar: The GNSS (global navigation satellite system) industry is continuously evolving, both in terms of technology and its user base. With the development of multiple GNSS constellations like GPS, GLONASS, Galileo, COMPASS, IRNSS and QZSS, GNSS receiver technology is taking into account the need of support for multiple constellations, keeping in mind the distinct requirements for each regional user segment.
The support for multiple GNSS constellations in GNSS receiver design is a trend that we have witnessed in the last few years, as more and more regional satellite navigation systems continue to be developed. Additional technologies like real-time kinematic (RTK) systems and global differential GNSS positioning are continuously trying to raise the bar for receiver positioning and performance in unique applications. RTK positioning, traditionally prevalent in the construction, agriculture and survey industries, has begun to be incorporated into applications in industries such as defence, unmanned vehicles, robotics, marine, mining, ports and container logistics.
GNSS positioning has traditionally been viewed as a stand-alone positioning technology, but with the recent advancements in sensor fusion, inertial, communication, photogrammetric and altitude sensors are increasingly being used in conjunction with GNSS receivers. These different sensors complement each other and function in such a way that the degradation of performance suffered by one in a particular environment is often offset by the superior performance of another in the same environment. Trimble has always been committed to supporting the growing regional and global satellite navigation systems, and offers products and services to help our customers increase their productivity
Could you provide an overview of Trimble’s RTK solutions? What factors were taken into consideration during their development?
Trimble uses positioning, communications and software technologies to improve productivity for customers and businesses. Trimble’s integrated technologies division offers navigation and communication products for original equipment manufacturers (OEM) and systems integrators. Our range of GNSS receiver modules and rugged box solutions offer the best of GNSS RTK technology in small and robust form factors.
With software upgradable configurations, our customers have the flexibility to integrate a single version of hardware in their design and upgrade to the configuration of their choice. Various software upgrade options like choice of GNSS constellation, frequencies, varying positioning modes with different levels of accuracy and output choices offer the freedom to test different versions in the field with the help of simple upgrade passwords. Positioning modes range from the very precise 1cm-level RTK to decimetre-level global differential GNSS augmentation, 2-3 decimetre differential GNSS and metre-level autonomous positioning.
While Trimble continues to invest in core positioning technology, factors such as ease of integration for customers, sensor fusion concepts, and the use of traditional positioning technology with communication and cloud-based tools like Ethernet, Wi-Fi and cellular are all factors that are contributing to the company’s next-generation products. With the launch of the Trimble BD920-W3G – the industry’s first OEM GNSS receiver module with onboard 3G modem, Wi-Fi and Bluetooth communications – Trimble remains committed to providing its customers with the latest technology in a smart package for ease of integration.
In the military/unmanned vehicle segment, what do you see as the potential applications that are able to integrate moving baseline RTK technology?
Moving baseline GNSS technology primarily offers two important solutions: a very accurate 1cm-level vector measurement, and accurate static and dynamic attitude (heading, roll, and pitch) with the help of multiple GNSS receivers and wireless links. This combination serves as a powerful solution in the defence and unmanned vehicle industry with potential applications such as:autonomous landing autonomous mid-air refuelling precise formation flying robotic sensor swarms waypoint navigation battlefield ISR.
These applications are not limited to the aerial domain, and can be applied to the marine as well as land segments. Civilian applications such as disaster management, pipeline and asset monitoring, precision agriculture, marine and offshore research, media and entertainment, border patrol and homeland security are some of the instances where RTK technology can be applied. Moving baseline RTK technology can also be used for precise heading and attitude determination when two or more receiver antennas are mounted on the same vehicle platform.
What wireless communication links does RTK support?
RTK works by sending satellite observation data and other information from the base station GNSS receiver to a rover GNSS receiver on which RTK differential algorithms calculate for the precise vector between the antennas of the two receivers. The information from the base to the rover is normally sent over a communication link such as VHF/UHF radio, Wi-Fi, Ethernet or cellular (GSM, 3G).
While Wi-Fi and Ethernet communication can be used for short baseline distances between the receivers doing RTK, radio and cellular communication is often used when the distances range from a few to tens of kilometres. The choice of communication link often plays an important factor in the overall performance of RTK positioning. Factors such as region-specific radio certification, link latency, distance between receivers, line of sight and obstructions are often considered when making this choice.
How does Trimble go about supporting its military and defence clients in this area? Is there a particularly salient case study that you would like to mention?
Trimble is a trusted supplier for US and allied military GPS users worldwide. Our goal is to provide our defence clients with world-class GNSS positioning technology in an easy-to-integrate form factor, so that while we focus on the technology, they can focus on end user productivity.
As mentioned earlier, a lot of potential military applications – autonomous landing/refuelling, precise formation flying, sensor UAV swarms and battlefield ISR -are possible with the help of Trimble’s moving baseline RTK Technology. The use of this innovative technology offers clients a unique advantage over regular GPS receivers in these specific applications. Furthermore, advancements in RTK and inertial technology will let military systems integrators develop highly customised military and civilian applications.
