GLOBAL NAVIGATION SATELLITE SYSTEM (GNSS): A Revolutionary Invention of Modern Day Science and Technology
Global Navigation Satellite System (GNSS) is a wireless communication system through which time and positioning of objects can be traced via exchange of signals between satellites. GNSS decrypts and decodes various commination signals to identify the location and timing of object(s) under observation. Popular examples of GNSS are USA’s NAVSTAR Global Positioning System (GPS) and Russia’s Global’naya Navigatsionnaya Sputnikovaya Sistema (GLONASS). In other words, GNSS is a measure of compatibility between different satellite systems for exchange of information like Global Positioning System (GPS), Galileo, GLONASS etc. GNSS empowers users to execute location based tasks without and limitations of national boundaries. This article will briefly discuss how GNSS is used in various applications of present modern era of science and technology along with example case studies for better understanding.
Applications of GNSS
GNSS positioning technologies are utilized globally for various applications like:
- Automobile poisoning
- Controlling of Marine Traffic
- Controlling of Aircrafts and Aviation
- Mapping and Geographic Information Systems (GIS)
- Engineering Surveying
- Photographic Geocoding
- Sky diving
- Social Networking
And many more.
This article briefly explains Photographic Geocoding and Controlling of Marine Traffic applications, importance of high accuracy requirements in these applications, technology utilization and the resulting benefits.
GNSS for Controlling Marine Traffic
Marine transport is a globally adapted mode of transportation for industrial exports and commercial trade between countries and cross boundaries.
Position tracking is very important for ships and vessels carrying worthy goods in deep oceans around the world due to reasons like:
- To Locate vessels’ movement and predict travel time between source and destination.
- To be prepared for any unforeseen natural disaster by tracking change in sea levels.
- To conduct search operations
- To perform constructional activities like paying of pipelines.
- To search and rescue sinking vessels.
- To explore oil rigs in the sea bed.
Manipulation of Data
Objects to be traced in installed with various sensors which transmit signals to date processing centers via interconnecting satellites. These signals are then decoded using various programs and equipment to determine positional coordinates of intended object. Transmitting time of GNSS signals from various satellites is very important to ensure accuracy of computed information. By evaluating change in positional coordinates with respect to time parameters like velocity, predication of travelling times etc. can be determined. High speed data processing equipment is an essential requirement to carry out quick calculations.
GNSS technologies commonly employed in maritime applications are briefly discussed as under:
- GPS: GPS is one of most important and widely used technology among GNSS which gives accurate real-time positioning and synchronization. Department of Defense (DoD) in United States of America has developed Navstar GPS which is an all-weather, space based navigation system to meet the needs of the USA military forces. Navstar GPS is helpful in accurate real time and continuous determination of position coordinates, velocity, and time in a common reference system, anywhere on or near the Earth.
- Automatic Identification System (AIS): AIS is an automatic system which utilizes electronic data exchange with nearby ships, base stations and satellites for dentification of vessels.
- Vessel Traffic Services (VTS): VTS monitors marine traffic (like air traffic control) by using radar, closed circuit televisions (CCTVs), VHF radiotelephone etc. VTS records vessel travelling routes and suggests navigational safety for a geographical area.
GNSS for Photographic Geocoding
Presently available smart devices enable users to mark a particular location to a photograph. This is called geotagging. Geotagging can easily be done provided you have latitudes and longitudes of intended location. A more detailed tagging includes altitude, compass bearings, azimuths etc.
Google Earth and Google Maps most popular free access platform that enable users to perform geotagging.
Accurate geotagging is helpful in pictorially representing location specific information. This gives user a brief idea of environmental conditions, needs and adaptations. Photos can be positioned onto a map to indicate a locality. This helps users to browse photos from a map, search for photos from a given area, and find related photos of the same place from other users for their easy reference.
Manipulation of Data
GPS and GIS are traditional technologies which are greatly in use for determination of location and position coordinates. Sensors communicate these to the interconnected satellites. Satellites in turn transmit this signals to some processing station that decrypts the information. This decoded information can then be tagged onto a photograph using methods described below.
GPS and GIS are only technologies compatible with photographic geocoding. it can be done in the following ways:
- Automatic with embedded GNSS receiver: In this method, relevant positioning details are automatically tagged to a captured photograph by an embedded camera which is fitted in GNSS receiver.
- Automatic with connected GNSS receiver: This method utilizes a wired or wireless (Bluetooth / WiFi) connection between GNSS transmitter and receiver for automatic tagging of positioning details to the photograph.
- Synchronizing with GNSS logger: In this method, capturer periodically logs the positional coordinates in a readily available GNSS logger which are then tagged onto the photo offline by comparing the photo timestamp with the GNSS logger timestamps and position.
- Manual Geocoding: Manual geocoding utilizes a mapping software to identify the photo coordinates and which are then marked onto the location by the user where the photo was taken.
Benefits of GNSS
Availability of useful applications helping users to find location based details outline the advantages of GNSS. GNSS not only finds its application in transportation and media services but also helps in centralizing information and establishing connections beyond national boundaries.
Earlier, there were no means of communication to track shipments, identify marine routes, and design sophisticated structures, trace the location of aircrafts. GNSS made all this communication possible which helped in enhancing the standards of sophisticated engineering designs leading to perfection.
Some of the many applications of GNSS these days are: