Globe is a three-dimensional scale model of a spheroid celestial body such as a planet, star,
or moon. Terrestrial globe is the globe of the Earth. Globe shows the actual reference to the
locations on Earth.
4. SURVEYING:
Generally, surveying is the systematic process of making measurements on the field from
which maps are drawn. The map is the most essential piece of equipment which the
geographer. Surveying is the science of measuring and recording distances, angles, heights
and sizes on the earth's surface to obtain data from which accurate plans and maps is made.
It is the measurement of dimensional relationships as of horizontal distances, elevations,
directions and angles on the earth's surface especially for use in locating property
boundaries, construction layout and map making.
5. REMOTE SENSING:
Generally, remote sensing refers to the activities of recording/observing/perceiving (sensing)
objects or events at far away (remote) places. in remote sensing, the sensors are not in direct
contact with the objects or events being observed.
a. Ariel Photographs:
Aerial photography is the taking of photographs of the ground from an elevated
position. Platforms for aerial photography include fixed wing aircraft, helicopters,
unmanned aerial vehicles (UAVs or drones) and balloons, etc. Mounted cameras may be
triggered remotely or automatically. Handheld photographs may be taken by a
photographer. Aerial photographs are used to take measurements of create maps and
to obtain important physical or cultural data.
b. Satellite Remote Sensing:
Satellite remote sensing is the acquisition of information on the Earth by the sensors
mounted on the satellites for this purpose. Satellite remote sensing is used in numerous
fields, including geography and most Earth Science disciplines eg. hydrology, ecology,
oceanography, glaciology and geology, it also nas military, intelligence, commercial,
economic, planning and humanitarian applications.
From satellite remote sensing, we also acquire Satellite photographs/ imageries, which
are like aerial photographs, but they are taken from space. Satellite photographs can
capture large areas of the Earth, but they can also zoom in very close.
6. GLOBAL POSITIONING SYSTEM (GPS):
The Global Positioning System (GPS) is a satellite based navigation system made up of a
network of 24 satellites placed into orbit by the U.S. Department of Defense. The Global
Positioning System is composed of 31 satellites orbiting 20,200 km above the earth. The
satellites are spaced in proit so that at any time a minimum of six satellites will be in view to
users anywhere in the world. The satellites continuously broadcast position and time data to
users throughout the world. This gives exact position anywhere on the Earth's surface. Many
countries operate their own satellite navigation systems:
United States: Global Positioning System (GPS)
Russia: Global Orbiting Navigation Satellite System (GLONASS)
China: BeiDou Navigation Satellite System (BDS)
European Union: Galileo
India: Navigation with Indian Constellation (NavIC), or
Indian Regional Navigation Satellite System (IRNSS)