Contents
What is ETM in remote sensing?
The Enhanced Thematic Mapper Plus (ETM+) instrument is a fixed “whisk-broom”, eight-band, multispectral scanning radiometer capable of providing high-resolution imaging information of the Earth’s surface.
What is the importance of radiometric calibration in remote sensing?
Radiometric calibration, also known as radiometric correction, is important to successfully convert raw digital image data from satellite or aerial sensors to a common physical scale based on known reflectance measurements taken from objects on the ground’s surface.
What is the purpose of radiometric correction?
radiometric corrections aim to precisely estimate the reflectivity of an environment, by compensating for the distortions related to the used antenna system, to positioning errors and certain characteristics of the electronic components.
What are the technical specifications of Landsat 7 ETM +?
ETM+ Technical Specifications 1 Sensor type: opto-mechanical 2 Spatial Resolution: 30 m (60 m – thermal, 15-m pan) 3 Spectral Range: 0.45 – 12.5 µm 4 Number of Bands: 8 5 Temporal Resolution: 16 days 6 Image Size: 183 km X 170 km 7 Swath: 183 km 8 Programmable: yes More
When did the reflectance calibration on Landsat 7 change?
Beginning in August 2016, the reflectance calibration of the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) has been updated to be consistent with the Landsat 8 Operational Land Imager (OLI) reflectance calibration.
How often is the ETM + instrument calibrated?
Analysis of large, unchanging desert sites in the Sahara has shown that the gains of the ETM+ instrument have degraded over the lifetime of the sensor. The degradation has been slow, a maximum of -0.21% change per year, but over 13+ years of operation, this amounts to calibration errors of up to 2.8%.
Why do we need to convert Landsat data?
These conversions provide a basis for standardized comparison of data in a single scene or between images acquired on different dates or by different sensors. This paper forms a needed guide for Landsat data users who now have access to the entire Landsat archive at no cost.