An overview of remote sensing technology, its applications in various fields, and the basic principles involved in capturing and interpreting remote sensing data.
Introduction to Remote Sensing
An overview of the principles, components, and applications of remote sensing for Earth observation and beyond.
| Aspect | Description |
|---|---|
| Definition | Acquisition of information about an object or area without physical contact, using sensors that detect and record electromagnetic (EM) energy reflected, emitted, or scattered from the target. |
| Key Idea | “Seeing from a distance” – satellites, aircraft, drones, or ground‑based platforms collect data that can be transformed into maps, images, and quantitative measurements. |
| Primary Sources of Energy | 1. Solar radiation (reflected sunlight) – most common for land and ocean studies. 2. Thermal emission (object’s own heat) – used for temperature and night‑time observations. 3. Artificial sources (radar, lidar) – emit their own signals and measure the return. |
| Spectral Region | Typical Wavelength (nm/µm) | Common Sensors & Uses |
|---|---|---|
| Visible (VIS) | 400–700 nm | True‑color imagery, vegetation health, water quality. |
| Near‑Infrared (NIR) | 700–1300 nm | Plant vigor (NDVI), soil moisture, land cover discrimination. |
| Short‑Wave Infrared (SWIR) | 1300–2500 nm | Mineral mapping, burn severity, moisture content. |
| Thermal Infrared (TIR) | 8–14 µm | Surface temperature, urban heat islands, volcanic activity. |
| Microwave (Radar) | 1 mm–30 cm | Surface roughness, flood mapping, all‑weather, day/night capability. |
| Lidar (Laser) | 1064 nm (near‑IR) & others | High‑resolution elevation, forest canopy structure, urban 3‑D modeling. |
Key concept: Different materials interact uniquely with each spectral band, enabling discrimination of land‑cover types, water quality, atmospheric constituents, etc.
| Resolution Type | Definition | Typical Values & Trade‑offs |
|---|---|---|
| Spatial | Size of the smallest object that can be resolved (pixel size). | High: 0.3 m (WorldView‑3); Medium |