Can I live without GPS? What the future holds for global navigation satellite systems

6.4 BILLION SMARTPHONES: Phones have evolved since 1876 when Alexander Graham Bell patented his device. Most smartphones today have tracking chips. There are an estimated 7.1 mobile phones, of which 6.4 billion are smartphones, according to BankMyCell data. The number of mobile devices is expected to reach 18.22 billion by 2025, an increase of 4.2 billion devices compared to 2020 levels. Today's smartphones are more than just communication devices; they're gaming, banking, geolocation devices too.

MODERN DAY TOOLS: Imagine ordering food. The delivery guy has no phone, no map and no way to take e-cash. Better to cook your own food, right? Today, we take it as a given that every person has a satnav gear on hand. We rely upon them for our daily lives. And we do take for granted such wonderful modern-day tools that make way-finding so much easier, that asking for directions from person to person is almost history. Even the olden days' greatest of explorers may have never even imagined they would exist one day.

15 BILLION MOBILE DEVICES: All told, there are an estimated 15 billion electronic mobile devices operating worldwide, many of them are navigation devices — up from about 14 billion in the previous year. Each receiver gets a signal from the sky for “geolocation" — the use of satellites or IP addresses to identify and track the whereabouts of connected electronic devices. Such devices are not just found in smartphones — they’re also in pet necklaces, watches, dashcams, glasses, gaming devices, footwear, cars, trucks, bikes, helmets, and other such gear… There are more than 40 types of equipment fitted with tracking devices.

BULKY, PRICEY: Tracking devices and map apps help us find our way around — that asking for directions has become almost non-existent. The first GPS devices were bulky. The NAV 1000 was the first portable GPS receiver developed for consumers by navigation company Magellan, weighed in at 1.5 pounds, and was pricey at $3,000 (that, too, with limited battery power). Today, each phone has a tiny satellite navigation tracking chip which does the magic. App Store and Google Play offer their users a wide range of Navigation Apps, which have successfully tested their quality by the mobile application testing services.

GNSS VS GPS, WHAT’S THE DIFFERENCE? Global Navigation Satellite System (GNSS) is a generic name for a group of artificial satellites that send position and timing data to receivers on the ground, sea or air — even as the satellites continue to orbit the planet. On the other hand, the GPS, or Global Positioning System (US government owned), is the first navigation satellite constellation. The US Space Force (under the Air Force) controls the GPS, which has at least 24 operational satellites. Till date, GPS has launched 72 satellites.

SATELLITE CONSTELLATION: It refers to a group of artificial satellites designed to work together is referred to as a “constellation”. Compared to a single satellite, a constellation can provide a near-global and permanent coverage. In general, at least one satellite in a constellation would be visible from everywhere on Earth.

MEDIUM-EARTH ORBIT: Most GNSS constellations are located in the medium-Earth orbit (MEO), or intermediate circular orbit (ICO). It is an Earth-centred orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) — between 2,000 km (1,243 mi) and 35,786 km (22,236 mi) above sea level). The boundary between MEO and LEO is an arbitrary altitude chosen by accepted convention; the boundary between MEO and HEO is the altitude of a geosynchronous orbit (GEO), in which a satellite takes 24 hours to circle the Earth.

ALTITUDE: A GNSS satellite typically weighs about 4,000 pounds (about 1,800 kg) and circle the globe at an altitude of about 12,000 miles (19,300 km) in medium-Earth orbit. By comparison, a low-earth orbit satellite is normally at an altitude of less than 1,000 km but could be as low as 160 km above Earth. Most telecommunications and broadcast satellites arena the geosynchronous earth-orbit (GEO), at an altitude of about 34,700 km. In contrast: an average commercial jet plane reaches an altitude of about 10-12 km. The Moon's orbit is around 9 times as large as geostationary orbit.

3 BILLION GPS USERS: The GPS, originally Navstar GPS, is the oldest and most widely-used satellite-based radionavigation system. It started operations in 1978 and was available for global use from 1994. The US makes it freely accessible to anyone with a GPS receiver. The GPS system has an estimated 3 billion civil and commercial users globally. The constellation is composed of 35 satellites (31 “healthy”, as of September 2017); 24 satellites hovering at about 20,200km (12,550 miles, also known as the medium-orbit, MEO) comprise the main constellation.

TRIANGULATION: For centuries, navigators relied on printed maps. Not anymore. In general, GNSS uses a method of “triangulation”. The distance to a specific device is measured via radio signals — which travel at the speed of light — in relation to a satellite and among satellites.

HOW DOES IT WORK? A receiver (chipset) in your phone (or tablet) “listens” to the signals constantly sent by the satellites. The receiver calculates its distance from three or more satellites it can “see” above. This allows it to figure out where you are. It works by measuring the distance to each satellite by the total time it takes to receive a transmitted signal. To compute the position and track movement, the receiver unit must lock on to the radio signal of three satellites (preferably 4).

GPS RECEIVER, SHRINK WRAPPED: Since radio signals travel at the speed of light (in vacuum space), about 299,792 km/s (or 186,000 miles/s), it can calculate how far the signal has traveled by figuring out how long it took to be received by your receiver. Mobile internet access can enhance the usefulness of the positioning information. Today's GPS receivers are so tiny they can attach to almost anything.

LATITUDE/LONGITUDE: That tiny receiver does all that calculation with the help of a low-power radio signal emitting from the satellites visible above. With some hi-tech math, the system is able to determine your location on the planet expressed in latitude (horizontal, from left to right, longitude (vertical or from top to bottom) and altitude (height). Combined with map data it can then tell you where you are.

CIRCLING THE EARTH 2X A DAY: Each GNSS satellite circles our planet twice a day. By comparison, low-earth orbit satellite, such as the International Space Station (408km above the earth), circles the earth up to 16 times a day (every 90 minutes). The third-generation GPS satellites have a much higher accuracy, better clocks, longer life and increased anti-jam/anti-spoofing capabilities.

LOCATING BUILDINGS: There are many uses for satellite navigation. For example, 200,000 building addresses in Abu Dhabi are now on Google Maps, while 19,000 street names also on the UAE’s Onwani addressing system. That’s just one of the benefits of modern-day life, thanks to satellite technology.

GPS-LIKE SYSTEMS: The GPS is not the only global navigation satellite systems (GNSS), though it was the first. There are other constellations at work or in the works. The number of GNSS constellations owned/operated by other governments with similar functionality is growing — including systems put together by Russia, the European Union, China, Japan and India. The UK has planned its own GNSS.

RUSSIA’S GLONASS: Global Navigation Satellite System (GLONASS) is Russia’s GNSS, which became operational in 1993 with 12 satellites in 2 types of orbits. At present, there are total 27 satellites in orbit, 23 of which operate for their targeted purposes, two are undergoing flight tests, one is in maintenance, while one is in reserve. In late April, one of the GLONASS-M satellites was removed from service for maintenance; it has become operational again in May according to space agency Roscosmos. The system provides real time position and velocity determination for military and civilian users. The satellites are located in middle circular orbit at 19,100 km (11,900 mi) altitude with a 64.8° inclination and a period of 11 hours and 15 minutes.

EUROPE’S GALILEO: Galileo is European Union’s GNSS constellation, run by the European Space Agency, and the European GNSS Agency will operate it. It is for both civilian and commercial use. The fully deployed Galileo system will consist of 30 operational satellites and 6 in-orbit spares. Galileo started offering Early Operational Capability from 2016 and reached full operational capability in 2020.

CHINA’S BEIDOU: BeiDou is China’s GNSS. It has total 22 operational satellites in orbit and the full constellation is scheduled to comprise 35 satellites. BeiDou has 2 separate constellations, BeiDou-1 and BeiDou-2. BeiDou-1 also known as first generation was a constellation of three satellites, which started operations in 2000, offering limited coverage and navigation services, mainly for users in China and neighboring regions. Beidou-1 was decommissioned in 2012.

BEIDOU-2: BeiDou-2, also known as COMPASS, is the second generation, which became operational in the year 2011, with a partial constellation of 10 satellites. Next is BeiDou-3. The first BDS-3 satellite was launched in March 2015. As of January 2018, nine BDS-3 satellites have been launched. BeiDou-3 became fully functional in 2020. On June 23, 2020, China launched the final satellite in its homegrown Beidou geolocation system, marking a major step in its race for market share in the lucrative sector.

JAPAN’S QZSS: The Quasi-Zenith Satellite System is the regional satellite navigation system from Japan, run by the country’s Satellite Positioning Research and Application Center. As per plans, the Japanese constellation will have 7 satellites, out of which 4 are already in orbit. The first satellite launched was in September 2010, and the last one was on October 10, 2017. QZSS is expected provide highly precise and stable positioning services in the Asia-Oceania region and is compatible with the US’ GPS.

MICHIBIKI SATELLITES: The Quasi-Zenith Satellite System (aka “MICHIBIKI”) provides higher navagition precision, especially in some urban or mountainous areas, where satellite signals can be hampered by skyscrapers or mountains. Sometimes, errors are caused by reflection waves. The QZSS satellites fly in the orbit passing through the zenith — just above — over Japan. This way, at least one of the satellites is deployed over Japan almost permanently. By placing a satellite at the near-zenith of, it will serve a more precise navigation in mountainous and urban regions where radio waves from a GPS satellite cannot find the necessary number of satellites for positioning.

INDIA’S NAVIC: The Indian Regional Navigation Satellite System (IRNSS), which was later given the operational name of NavIC or NAVigation with Indian Constellation, is the regional satellite navigation system of India. Launched and operated by the Indian Space Research Organization (ISRO), IRNSS covers India and nearby regions extending up to 1,500 km. All the seven satellites are in orbit. Currently, 3 IRNSS satellites are in the geostationary orbit; 4 others are in geosynchronous orbits.

REGIONAL NAVIGATION SYSTEM: The IRNSS is an independent regional navigation system being developed by India. It is similar to the GPS of the US, Glonass of Russia, Galileo of Europe and China’s Beidou. Each satellite has three clocks and a total of 27 clocks for the navigation satellite system (including the standby satellites) were supplied by the same vendor. The clocks are important to provide precise locational data.

PENETRATING OBSTRUCTIONS: With the first-generation satellites, obstacles such as mountains and buildings can block the relatively weak GPS signals. The GPS III satellites will continue to be launched through about 2025. The new GPS satellites can provide better positioning accuracy because of a new set of atomic clocks carried aboard each satellite. Because they have more transmitter power, GPS reception can be more reliable, even indoors and in dense urban areas.

THE FUTURE IS SELF DRIVING VEHICLES: Digital navigation here. Going back to a printed map is a no-go. Satellite tracking with millimetre accuracy will become increasingly valuable. Real-time geolocation is a key ingredient in the future of self-driving vehicles. With robotaxi services, a “safety driver” will increasingly be present only as a “backup”. The main driver will be software, enabled by the next-generation GNSS.

ALGORITHMIC NAVIGATION: On Saturday (October 23, 2021), a new racing record was set. The winner was not a driver — but an algorithm aided by cameras and trackers at the Indianapolis Motor Speedway. The top car clocked an average s peed of 218 km/h (135 mph). The event, known as the first Indy Autonomous Challenge, is dedicated to self-driving cars. It had a $1 million prize, won by the Technical University of Munich (TUM). Digital navigation is a key ingredient in ushering autonomous vehicles into a new era.