Remote sensing is the science of acquiring images and data about objects from a distance using sensors. It involves recording electromagnetic radiation reflected or emitted from objects using platforms like satellites, aircraft, and drones. There are two main types - passive sensing, which detects natural radiation, and active sensing, which emits energy and measures its reflection. Remote sensing has various applications like mapping land use, monitoring agriculture and forests, and studying geology, oceans, and the environment. It provides data over large and inaccessible areas quickly and cost-effectively. However, interpretation requires skill and data may need ground verification.

1. REMOTE SENSING

2. CONTENTS:
 Introduction
 What is remote sensing?
 Remote sensing technologies
 History of Remote Sensing
 Applications of Remote Sensing
 Advantages
 Disadvantages
 References

3. INTRODUCTION
 Remote sensing is the art and science of recording, measuring,
and analyzing information about a phenomenon from a
distance. Humans with the aid of their eyes, noses, and ears
are constantly seeing, smelling, and hearing things from a
distance as they move through an environment.
 In order to study large areas of the Earth’s surface
geographers use devices known as remote sensors. These
sensors are mounted on platforms such as helicopters, planes,
and satellites that make it possible for the sensors to observe
the Earth from above.
 Remote sensing has been used for earthquake research from
the 70s, with the first appearance of satellite images. First of
all it was used in structural geological and geomorphological
research.
 Active faults and structures were mapped on the base of
satellite images. This method is very limited in time series
analysis.

4. What is remote sensing?
 Remote Sensing: remote sensing is science
 acquiring,
 processing, and
 interpreting
Images and related data that are obtained from ground-based,
air-or space borne instruments that record the interaction between
matter (target) and electromagnetic radiation.
 Remote Sensing: using electromagnetic spectrum to image the
land, ocean, and atmosphere.
 The scanning of the earth by satellite or high-flying aircraft in
order to obtain information about it.

5. Remote Sensing concept

7. Types of Remote Sensing
 Satellite Remote Sensing
 Aerial Remote Sensing
 LiDAR (Light Detection and Ranging)
 RADAR (Radio Detection and Ranging)
 Hyperspectral Imaging
 Infrared and Thermal Imaging
 GPS (Global Positioning System)
 Unmanned Aerial Vehicles (UAVs) or Drones

8. Types of sensors
Sensor Type Subtypes Applications
Optical Sensors VNIR, SWIR, TIR
Land cover analysis, vegetation health,
temperature studies
Radar Sensors SAR, InSAR
Terrain mapping, agriculture, disaster
monitoring
LiDAR -
Topographic mapping, forestry, urban
planning
Hyperspectral
Sensors -
Agriculture, mineral exploration,
environmental monitoring
Multispectral Sensors -
Land cover classification, vegetation
analysis, monitoring
Passive vs. Active
Sensors
Passive (e.g., optical), Active
(e.g., radar)
Natural radiation detection, emitted or
reflected energy
Radiometric Sensors -
Quantifying energy reflected or emitted
objects
Infrared Sensors -
Temperature monitoring, material
identification
GPS -
Georeferencing and positioning for data
accuracy
Digital Cameras -
High-resolution optical imagery for visu
observation
Magnetometers - Geological studies, mineral exploration
Spectrometers - Material composition analysis

9. TYPES OF REMOTE SENSING:
There are two main types of remote sensing:
1. Passive remote sensing and
2. Active remote sensing.
1. PASSIVE SENSORS:
 Detect natural radiation that is emitted or reflected by the
object surrounding area being observed.
 Reflected sunlight is the most common source of radiation
measured by passive sensors.
 Examples of passive remote sensors include film photography,
infrared, and radiometers.

10. 2. ACTIVE REMOTE SENSING:
 On the other hand, emits energy in order to scan objects and
areas where upon a sensor then detects and measures the
radiation that is reflected or backscattered from the target.
 Radar is an example of active remote sensing where the time
delay between emission and return is measured, establishing
the location, height, speeds and direction of an object.

12. MODERN ADVANTAGES OF REMOTE
SENSING:
 Its satellite data are used as basic inputs for the inventory of
natural resources and development processes like agriculture,
soil, forestry, and geology (Chavez et al., 1977).
 There are other important technologies that are available to
geographers as well, such as
 Maps,
 Aerial photography/photogrammetry/pictometry,
 SAR (Synthetic Aperture Radar )
 LiDAR (Light Detection and Ranging )
 SONAR, and
 GIS.(Geographic Information System)

13. PRINCIPLES AND PROCESS OF REMOTE
SENSING:
A - Energy source or Illumination
B - Radiation and The atmosphere
C - Interaction with the target

14. D - Recording of energy by the sensor
E - Transmission, Reception, and Processing
F - Interpretation and Analysis
G - Application

15. GENERAL REMOTE SENSING APPLICATIONS:
1. Agriculture
2. Forestry
3. Geology
4. Hydrology
5. Sea ice
6. Land cover and land use
7. Mapping
8. Oceans and coastal monitoring
9. Geography

16. APPLICATIONS OF REMOTE SENSING IN
CIVIL ENGINEERING:
1. Regional planning and Site investigations
2. Terrain mapping and analysis
3. Water resources and Hydrological engineering
4. Town planning and Urban development
5. Mining and Mineral exploration
6. Transportation network analysis
7. Landslide studies

17. ADVANTAGES :
 Provides data of large areas
 Provides data of very remote and inaccessible regions
 Able to obtain imagery of any area over a continuous period of time
through which the any anthropogenic or natural changes in the
landscape can be analyzed
 Relatively inexpensive when compared to employing a team of
surveyors
 Easy and rapid collection of data
 Rapid production of maps for interpretation

18. Disadvantages
 The interpretation of imagery requires a certain skill level
 Needs cross verification with ground (field) survey data
 Data from multiple sources may create confusion
 Objects can be misclassified or confused
 Distortions may occur inanimage due to the relative motion of
sensor and source

19. CONCLUSION
 Remote sensing data has proven to be an important tool in
geography.
 Remote sensing has progressively expended applications in
various fields such as urban-regional planning, utilities
planning, health planning, geomorphology, and resource
planning.
 Because of its varied applications and ability to allow users to
collect, interpret, and manipulate data over dangerous areas,
remote sensing has become a useful tool for all geographers,
regardless of their concentration.
 This is the first survey of its kind to measure, in a systematic
way, losses and gains in forest land use between 1990 and
2005 at the global, regional, climatic domain and ecological
zone levels of aggregation.

20. THANK YOU