Unit 1 Fundamentals of Environmental Sciences - Ground Truthing in Remote Sensing | ground truth data collection | UGC NET/JRF Environmental Science

Ground truth is a term used in various fields to refer to information provided by direct observation. In remote sensing, "ground truth" refers to information collected on location. Ground truth allows image data to be related to real features and materials on the ground. The collection of ground truth data enables calibration of remote-sensing data, and aids in the interpretation and analysis of what is being sensed. Examples include cartography, meteorology analysis of aerial photograph, Satellite imagery and other techniques in which data are gathered at a distance. More specifically, ground truth may refer to a process in which a pixel on a satellite image is compared to what is there in reality (at the present time) in order to verify the contents of the "pixel" on the image (noting that the concept of a "pixel" is somewhat ill-defined). In the case of a classified image, it allows supervised classification to help determine the accuracy of the classification performed by the remote sensing software and therefore minimize errors in the classification such as errors of commission and errors of omission. Ground truth is usually done on site, performing surface observations and measurements of various properties of the features of the ground resolution cells that are being studied on the remotely sensed digital image. It also involves taking geographic coordinates of the ground resolution cell with GPS technology and comparing those with the coordinates of the "pixel" being studied provided by the remote sensing software to understand and analyze the location errors and how it may affect a particular study. Ground truth also helps with atmospheric correction. Since images from satellites obviously have to pass through the atmosphere, they can get distorted because of absorption in the atmosphere. So ground truth can help fully identify objects in satellite photos. #evs4ntanet #environmental_science #ground_truth_data #evs_4ntanet #ugc_net/jrf_evs #remote_sensing #ground_truthing #ground_truth_data_collection