Global Navigation Satellite Systems (GNSS) and positioning technologies have become a part of our lives for many years now. GNSS is basically focused on its potential to determine a specific position in the global system anywhere and anytime in a simple, fast and cost-effective manner. From the beginning, several developments have contributed towards the innovation in the technology and have opened up huge opportunities for the solution providers of GNSS chipsets.
GNSS encloses some spectacular technology that most of us take for granted. The increased functionality of locations-based devices means that we are entering an era where we have easy access to information and pin point the geographic location of a user’s receiver anywhere in the world. Right now, there are applications that cover public transport, public works and civil engineering, immigration and border control, police; monitoring of prisoners, environmental management, medical applications and people with disabilities, sports, tourism, waste disposal etc. However, it is clear that we are going to witness an even wider range of location-based applications in the future?many of which will be tailored to meet the needs of specific market niches and individuals. The opportunities for innovation are abound and the chipset technology is evolving to meet the market?s fast-changing requirements. The solutions should, therefore, employ GNSS chipsets which have leading-edge technology while making the solutions future proofed.
The GNSS application plays a major role in many fields from transportation to multi domains. The architecture and the performance of RF front-end is the key contributor to fulfill strict requirements of the GPS/GLONASS system, because it consists of the whole line-up between the GNSS antenna and the integrated GNSS chipset. Other options might include selecting the chipset having the highest sensitivity, lowest power consumption, or support for dead reckoning and geo-fencing.
On the basis of the particular technology use, GNSS precision varies. For example, The Department of Defense of United States originally used an intentional degradation (known as “Selective Availability,” or “SA”) of GPS signals to prevent potential military adversaries from using the positioning data.
Enabling optimum solutions
Original equipment manufacturers (OEMs) only need to design and manufacture one Printed Circuit Board (PCB), the platform that provides the requisite location-based service in the module. Different chipsets do not need to be placed on the board. Therefore, development efforts and time to market are reduced. In addition, different GNSS solutions can be marketed on the same footprint.
Some multi-constellation GNSS modules have been designed for global compliance with the whole set of GNSS constellations, either those already in place (GPS,QZSS and GLONASS) or constellations that are under deployment (Galileo and Compass/Beidou).
GNSS Interface
The GPS and other satellite navigation signals are very weak signals and they are relatively vulnerable to interference. That is the phenomenon where other un-required signals disturbs the navigation signal and causes reduced accuracy.
Since GNSS satellite signals travel at the speed of light, the distance or range to each satellite is determined by precisely measuring the time it takes for the signals to be transmitted by high-orbit GNSS to reach the receiver and multiplying this transit time by the speed of light. Most of the modules have hybrid positioning system that combines GPS, GLONASS, and SBAS to provide a high performance position reporting and navigation solution.
The GNSS chipsets are integrated into different module families which have the same foot print and electrical and logical interfaces but which employ different radio access technologies. The modules are easily integrated cellular as GPS commands are integrated in command interface.
With the emergence of multiple positioning technologies, such as Wi-Fi, cellular, satellite technological systems and sensor-based systems, designers are needed to experiment the chipsets in geographical environments.
Adoption of GNSS continues to grow and expand in the other areas and niche markets. Many of GNSS applications are subject to Crystal oscillation to vibration and mechanical shock which causes inaccurate measurement or satellite tracking failure. For dynamic GNSS applications with operational expectations that cannot be compromised during any degree of vibration. Quartz Lock Loop (QLL) technology ensures for superior GNSS tracking in high-vibration environments. However, testing two different GNSS receiver products shows vulnerabilities at many vibration frequencies and magnitudes with sensitivity and the ability to mix and match signals from different systems will allow designers to create receivers that can perform reliably anywhere in the world.
In the developing countries, GNSS application plays a major role and offers a cost-effective Satellite navigation and positioning data used in multi domains include mapping and surveying, monitoring of the environment. With several GNSS applications coming into play since the last decade, the spectrum of usage in our daily life is also significantly enhanced.
