Remote Sensing: INTRO

Technology to acquire, receive information about the Earth's surface without being in the actual surface:

American Society for Photogrammetry and Remote Sensing in 1988: The art, science and technology of obtaining reliable information about physical objects and the environment, through the process of recording, measuring and interpreting imagery and digital representations of energy patterns derived from non-contact sensor systems.

•             (ENERGY SOURCE ~ RADIATION ~ TARGET INTERACTION)
•             (RECORDING REFLECTED or EMITTED ENERGY)
•             (ANALYZING AND INTERPRETING THEM)

Platforms: Aerial Television, Photography, Satellite Optical Sensor, Space Shuttle, Airborne SAR

Technology involves interaction between radiation and targets

*Passive RS* (external source of energy not needed, suffers from variable illumination condition of Sun [influence of atmosphere])

*Active RS*   (own source of energy, illuminations signal controlled)

Illustration of Remote Sensing (Source: Commons)

a. Source of Energy: provides electromagnetic energy

b. Radiation and the atmosphere: interaction with the atmosphere 

c. Target: interaction with the target (signatures are different)

d. recording of the energy and transmission: electromagnetic radiation collected, and transmitted to the earth stations

e. Reception and processing 

f. Interpretation and analysis

g. Application to the domain: weather forecasting, climate change etc.

History:

Hot Air Balloon, 1858AD

Pigeon mounted Camera, 1903

Plane Mounted cameras 1914-1945 WWII

1st spaced Photo, 1947 (K12 camera)

MR 3 spacecraft, US 1963

Apollo Moon Landing Mission

RS starts from 1972 ERTS (Earth Resources Technology Satellite); renamed Landsat

1986 SPOT (10 PAN, 20 m spatial resolution)

1970-1980 Advances in digital image processing

1980s : Hyper-spectral Sensors

1990s: Global Remote Sensing Systems

 

~ROUGH NOTES Based on lectures from IIT Roorkee (Online Course)