Optical Remote Sensing
The Optical Remote Sensing technique used to detect water properties. In this article describes about the general principles and applications of optical remote sensing.
Table of Contents
Optical Satellite System
Characteristics of representative optical satellites:
| Satellites | Spatial resolution (meters) | Revisit time (days) | Spectral range (μm) number of bands | Number of bands |
|---|---|---|---|---|
| Landsat | 15–120 | 16 | 0.45–12.5 | 11 |
| ASTER | 15–90 | 15 | 0.52–11.65 | 15 |
| SPOT | 10–20 | 26 | 0.45–1.75 | 5 |
| IKONOS | 1–4 | 1–4 | 0.45–0.90 | 5 |
| Quickbird | 0.61–0.72 | 1–6 | 0.45–0.9 | 4 |
| IRS | 5.8–70 | 5–24 | 0.52–1.7 | 4 |
Optical Satellite Data
There are several data acquisition options available including photography, aerial sensors, and sophisticated satellite scanners. However, a satellite system offers these advantages:
- Digital data gathered by a satellite sensor can be transmitted over radio or microwave communications links and stored on servers, DVDs, CDs, or magnetic tapes, so they are easily processed and analyzed by a computer.
- Many satellites orbit the Earth, so the same area can be covered on a regular basis for change detection.
- Once the satellite is launched, the cost for data acquisition is less than that for aircraft data.
- Satellites have very stable geometry, meaning that there is less chance for distortion or skew in the final image.
Applications of Optical Remote Sensing
For coastal water-quality monitoring, Remote Sensing data sets which combine a synoptic viewpoint with the ability to measure the reflected energy from the water surface in different spectral regions, are increasingly available for coastal water-quality applications.
- Land-Use and Land-Cover Mapping
- Urban Heat Island Mapping
- Urban Vegetation Phenology
- Rock Outcrops Identification