12th Standard Geography — Geoinformatics Online Test
Unit 6 of 12th Geography introduces Geoinformatics, the integration of remote sensing, GIS and GNSS. It explains the elements of remote sensing, active and passive sensors, platforms and types of satellites, the components and functions of GIS, and the global navigation satellite systems of different countries with their applications.
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About Geoinformatics
Medium ~55 min study
Geoinformatics is the sixth unit of the Tamil Nadu State Board Class 12 Geography book. It defines Geoinformatics as the integration of remote sensing, the Global Navigation Satellite System and the Geographic Information System dealing with spatial information, and shows how these three components have changed surveying and map making.
The lesson follows the remote sensing process from the energy source to interpretation, describes ground, air and space borne platforms, explains geostationary, sun-synchronous and spy satellites, and then moves to the five components and four functions of GIS and the navigation systems run by the USA, Russia, the European Union, China, Japan and India.
This page brings together the ten printed one mark questions of the book exercise, with answers checked against the lesson, and twenty additional questions with short explanations.
What you'll learn
- Name the three major components of Geoinformatics.
- Explain the six elements of the remote sensing process.
- Distinguish active and passive sensors and give examples.
- Compare geostationary, sun-synchronous and spy satellites.
- List the components and functions of GIS.
- Match each GNSS system with its country and state its main features.
Before you start
- The idea of maps, scale and surveying from earlier Geography classes.
- Basic knowledge of the electromagnetic spectrum and light.
- Latitudes, longitudes and the rotation of the earth.
Topics covered in this chapter
Geoinformatics explained
What this lesson covers
Remote sensing
Remote sensing collects information about terrestrial objects using camera and sensor systems. Its elements are the energy source, radiation and the atmosphere, interaction with the target, recording by the sensor, transmission, reception and processing, and interpretation and analysis. Scattering and absorption modify the energy in the atmosphere. Image processing has three categories: restoration, enhancement and information extraction.
Sensors and platforms
Active sensors produce their own energy and work in the microwave region; passive sensors depend on the sun and work only in daylight. Platforms are ground borne, air borne (balloons, drones, aircraft) and space borne. Satellites are geostationary, polar orbiting or sun-synchronous, and spy satellites. The applications of remote sensing range from agriculture and forestry to geology, oceanography, cartography, meteorology, topography and urban planning.
GIS
GIS emerged in the past two decades as a tool for urban and resource planning. Its components are hardware, software, data, people and methods, and its functions are data capture, data storage, data manipulation, and query and analysis.
GNSS
GNSS is the collection of the world's satellite positioning systems: GPS, GLONASS, Galileo, BeiDou, QZSS and India's IRNSS. Their uses include consumer devices, transport, port automation, machine control, precision agriculture, surface mining and survey.
Common mistakes to avoid
- Matching Galileo with Japan. Galileo belongs to the European Union; Japan's system is QZSS.
- Calling METEOSAT or INSAT sun-synchronous. They are geostationary; LANDSAT, IRS and NOAA are sun-synchronous.
- Saying active sensors depend on the sun. Active sensors produce their own energy; passive sensors depend on the sun.
- Doing image enhancement before restoration. Enhancement distorts the original digital values, so restoration comes first.
- Taking data capture as the heart of GIS. The book says it is the analytical capability of the system.
Test yourself on these with the practice test, then check the worked reasoning in the solved MCQs.
Frequently asked questions
What is Geoinformatics?
Geoinformatics is the integration of remote sensing, the Global Navigation Satellite System and the Geographic Information System dealing with spatial information. These are its three major components.
What is the difference between active and passive sensors?
An active sensor generates its own energy, illuminates the target and records the reflected energy, working in the microwave region. A passive sensor records reflected solar radiation and works only in daylight.
What are the three types of satellites in the lesson?
Geostationary satellites such as INSAT and INTELSAT, polar orbiting or sun-synchronous satellites such as LANDSAT and IRS, and spy satellites such as Corona, MIDAS and SAMOS.
What are the components of GIS?
Hardware, software, data, people and methods or procedures. Software such as ArcGIS and QGIS uses a Relational Database Management System to store data.
Which was the first GNSS system?
GPS of the United States was the first GNSS system. It was launched in the late 1970s by the US Department of Defence and uses 24 satellites.
What is IRNSS?
IRNSS is India's autonomous regional navigation satellite system developed by ISRO. It serves India and the region up to 1,500 km from its boundary, offering a Standard Positioning Service and a Restricted Service.
What was Kalamsat?
Kalamsat was the world's lightest satellite, weighing 64 grams, designed by 18-year-old Tamil Nadu student Rifath Sharook and flown by a NASA sounding rocket on 22 June 2017.
Last updated 19 October 2026