GNSS Market Research and Analysis GPS/GNSS Networks and Services The Global Market for GNSS Augmentation Infrastructure and Services 2009-2013 March 2009 Abstract ©Position One Consulting Pty Ltd 2009 All rights reserved Authors Robert Lorimer & Eric Gakstatter
Global Navigation Satellite Systems (GNSS) include the United States GPS (the most commonly used today), Russia's Glonass, the EU's Galileo, China's Compass, the Indian Regional Navigation Satellite System (IRNSS) and Japan's Quasi-Zenith Satellite System (QZSS).
The signals from all these GNSS are subject to a myriad of errors and may not always tell the truth. Whereas this is not a problem for casual users or those who can tolerate such errors, there are many applications where integrity and accuracy must be improved.
GNSS augmentation infrastructure monitors the accuracy, availability, continuity and integrity of navigation satellite signals by analysing their performance at known points on the earth's surface called reference stations. GNSS augmentation services then transmit error corrections and integrity information to user equipment in a timely and reliable manner. There are two transmission methods for augmentation services: Satellite Based Augmentation Systems (SBAS) transmit services via communication satellites and Ground Based Augmentation Systems (GBAS) transmit services using terrestrial communications such as data radios, mobile networks or the internet.
GNSS augmentation infrastructure includes Continuously Operating Reference Stations (CORS), RTK Networks, RTK Clusters, Differential GPS (DGPS) such as the United States Coast Guard system and SBAS integrity systems which include the Wide Area Augmentation System (WAAS), European Geostationary Overlay System (EGNOS), Japan's MTSAT Space-based Augmentation System (MSAS) and India's GPS Aided Geo Augmented Navigation (GAGAN). What all these infrastructures have in common is their use of multi-frequency GNSS reference stations to monitor the performance of the orbiting GNSS. Today's reference stations are predominantly dual frequency receivers (L 1/L2) monitoring the United States Global Positioning Systems (GPS). In the period 2009-2013, new GPS frequencies will become available (e.g. GPS L5), others will be available on more GPS satellites (e.g. L2C) and other GNSS will reach the point where they are commonly used in Augmentation infrastructure (e.g. GLONASS, Galileo etc.). These changes will encourage many infrastructure owners to replace today's dual frequency GPS reference stations with multi¬frequency and multi-constellation GNSS reference stations.
In addition to the replacement market for multi-frequency and multi-constellation reference stations, the number and geographic coverage of GNSS augmentation systems and augmentation services continue to grow and generate additional demand for reference stations.
Since the early 1990's GNSS augmentation infrastructure such as CORS, Marine DGPS, SBAS, GDGPS, IGS, etc. have been government sponsored and their augmentation services have often been available at no charge. Users were predominantly scientists (e.g. Geodesists), government mapping agencies and professions such as marine and aviation. Legal and safety-of-life concerns meant these users were often intimately involved in the design and implementation of the infrastructure and services. Privately funded augmentation infrastructure providing commercially priced augmentation services have also been around since the 1990's (e.g. Omnistar's Global SBAS services) and have proved popular in the offshore, mapping and agricultural markets.
Since 2000, there has been a steady growth of real-time RTK infrastructure and services which has transformed the world of precise positioning. Two types of infrastructure have emerged.
RTK Clusters were borne from the traditional base/rover concept of single baseline solutions, but scaled to include many permanently installed reference stations. RTK Clusters provide single baseline solutions, but the user/subscriber has many reference stations to select from based on baseline distance and communications link. RTK Clusters have become particularly popular in the agriculture market where RTK has been adopted for machine guidance in applications such as auto-steer.
Real Time Network's (RTN) are more complex, survey/engineering/construction oriented infrastructure where accuracy, reliability and robust precise positioning are essential. The complexity of RTN lies in the software that controls and monitors the network of reference stations. It creates the optimized corrections based on data from many or all of the reference stations in the network. Typically, corrections are delivered via NTRIP (Network Transport of RTCM via Internet Protocol) through wireless (mobile phone) networks which have a related subscription cost.
RTN are generally well planned infrastructure, often based on existing CORS networks that are expanded and densified. They are typically tied to and monitored for stability in a state-of-the-art reference frame and operate using open standards and protocols. There are several business models in use for RTN. These include RTN funded, developed and managed by national, state or provincial governments in a not-for-profit manner, purely commercial endeavors and public-private-partnership (PPP) arrangements.
By contrast, RTK Clusters are more likely to be an ad-hoc infrastructure at a local level using proprietary GNSS augmentation standards. In these applications, the monitoring of the reference frame isn't as stringent as an RTN. The primary focus is the repeatability of the measurement so that users, such as farmers, can realize precise "pass-to-pass" measurements for applications requiring a high level of precision such as tractor auto-steering. RTK Cluster correctors are typically delivered using data radios with spread spectrum or other data radio technology.
Unlike RTK Networks, RTK Clusters are rarely, if ever establish by government entities. They are typically established by local equipment dealers or by cooperative arrangement among the users.
Whether publically funded or privately funded, once infrastructure and services cover a locality, existing precision GNSS users have a choice of continuing to operate (or share) their own reference station or consume the augmentation services. Likewise new precision GNSS users have to decide whether to purchase their own reference station or simply subscribe to an appropriate service. Operator revenues from precision augmentation services are forecast to be the fastest growing part of the precision GNSS value chain (Position Report, 2008: GNSS Precise Positioning Market Report 2008-2012).
The combined value of precision GNSS augmentation infrastructure and precision GNSS augmentation services is forecast to grow from US$263M in 2009 to US$504M in 2013.