Digital Sources

Digital Data Sources

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1. digital databases

Following animation will explain digital databases as the primary source of digital data. Click on it to view the full animation.

2. Introduction to Remote Sensing as Primary Digital Source Data

The following animation will explain remotely sensed dataas the primary source of digital data. Click on it to view the full animation.

2.1 Remote sensing satellites: SPOT and Landsat

SPOT Satellite (optional link) is passive a remote sensing satellite launched by France. Visit their web site by clicking on the link above for additional information about the SPOT satellite and its applications.

Band	Wavelengths	Appears to us
Band-1	0.5-0.6µm	Visible Green wavelength
Band-2	0.6-0.7µm	Visible Red wavelength
Band-3	0.7-0.8µm	Near Infrared wavelength
Band-4	0.8-1.1µm	Mid Infrared wavelength

SPOT wavebands are useful to detect differences in water quality, vegetation, and rock.

The Landsat satellite (optional link) is also passive a remote sensing satellite, launched by United States of America. Visit the Landsat homepage by clicking the yellow link above, for additional information about the satellite and its applications.

The Landsat-TM satellite records values for seven bands at 30-meter resolution.

Band	Wavelengths	Appears to us
Band-1	0.45 to 0 .515µm	Visible Blue wavelength
Band-2	0.525 to 0.605µm	Visible Green wavelength
Band-3	0.63 to 0.690µm	Visible Red wavelength
Band-4	0.75 to 0.90µm	Near Infrared wavelength
Band-5	1.55 to 1.75µm	Mid Infrared wavelength
Band-6	10.40 to 12.5µm	Thermal Infrared wavelength
Band-7	2.09 to 2.35µm	Mid Infrared wavelength
Panchromatic	0.52 to 0.90µm	Visible wavelength at 15 m resolution

The Landsat wave bands are able to detect temperature, differences in water quality, vegetation, rock and snow.

3. Use of Remote Sensing Data

The following animation will explain the use of remotely sensed data.