LIDAR AND RADAR ITS APPLICATIONS IN RS & GIS, Slides of Engineering Geology

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LIDAR AND RADAR

AND ITS APPLICATIONS IN

RS AND GIS

 U.SRI CHARAN SAI KRISHNA

(BT14CIV089)

 SHEKHAR KUMAR (BT14CIV081)

 JAYASHREE OJHA (BT14CIV033)

INTRODUCTION

• (^) Remote sensing comprises of two parts: 1. Active remote sensing: Active sensors emit their own energy source for illumination. The energy source hits objects and the reflected energy from the objects is detected and measured by sensors. 2. Passive remote sensing: Passive sensors can only detect energy source when the naturally occurring energy is available. •. (^) RADAR, LIDAR AND SONAR comes under the common active remote sensing systems.

• RADAR :

1. RADIO DETECTION AND RANGING
2. transmits microwaves in pulses.
3. Uses the long wavelength microwaves(1- 100cm) •. (^) LIDAR:
4. LIGHT DETECTION AND RANGING
5. transmits optical laser light in pulses.
6. Uses the short wavelength laser light •. (^) SONAR:
7. SOUND NAVIGATION AND RANGING
8. Sound waves through water coloumn.

WHAT IS RADAR?

• (^) RADAR , which stands for Ra dio D etection A nd R anging, is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects.

COMPONENTS OF RADAR SYSTEM

1. A Transmitter: The signal is first generated using a waveform generator and then amplified in the power amplifier. 2. Waveguides: The waveguides are transmission lines for transmission of the RADAR signals. **3. Antenna

4. Duplexer:** allows the antenna to be used as a transmitter or a receiver. **5. Receiver
5. Threshold Decision:** The output of the receiver is compared with a threshold to detect the presence of any object

RESOLUTIONS IN RADAR

• (^) RANGE RESOLUTION: Resolution in the range direction is determined by the depression angle and by the pulse length.
• (^) AZIMUTH RESOLUTION: Resolution in the azimuth direction can be determined by the slant range and antenna length.   pulse length speed of light 2 cos 2 cos depression angle r c R      slant range wavelength antenna length a S R L    

APPLICATIONS of RADAR CLIMATE MONITORING COASTAL ZONE MONITORING LAND USE,AGRICULTURE AND FORESTRY NATURAL RESURCES EXPLOITATION. MAP COMPILING AND UPDATING MARINE ENVIRONMENT(HAZARDS AND RISKS) NATURAL DISASTERS MISSILE GUIDANCE SYSTEM

WHAT IS LIDAR?

• (^) LIDAR , which stands for Light D etection a nd R anging, is a remote sensing method that uses light in the form of a pulsed laser to measure ranges (variable distances) to the Earth.

Characteristics of LIDAR

• (^) Uses frequencies in the near UV, visible, and near IR.
• (^) Wavelengths vary to suit the target: from about 10 micrometers to the UV (approximately 250 nm).
• (^) One of the most common wavelengths is 532 nm.
• (^) Typically light is reflected via backscattering.

COMPONENTS OF LIDAR SYSTEM

1. Laser — 600–1000 nm lasers are most common for non-scientific applications. 2. Scanner and optics — How fast images can be developed is also affected by the speed at which they are scanned. 3. Photodetector and receiver **electronics

4. Position and navigation systems** 14

Mapping Major Land Cover

Types and Retrieving the

Age of Secondary forests

with Radar Remote

Sensing.

OBJECTIVE

• (^) The main objective is to

1. Map the major land cover types(Mature forest , Non-forest and Secondary forests).
2. Retrieve the age of secondary forest across the three sites.

STUDY AREAS

• (^) This study has taken across three sites of 5000km 2 in the Brazilian Amazon:Manaus(2.6° S, 60.2° W), Santarém (3.1° S, 54.8° W) and Machadinho d'Oeste(9.5° S, 62.4° W)