rule-images-p1

The main result of supervised satellite image classification process is the classification map. But apart from it, you can still get another result – the rule image. In this post, we will look at what it is. When we perform supervised image classification, the software calculates a mathematical criterion (which depends on the classification algorithm) […]

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minimum-distance

We have already posted a material about supervised classification algorithms, it was dedicated to parallelepiped algorithm. Now we are going to look at another popular one – minimum distance. In contrast with the parallelepiped classification, it is used when the class brightness values overlap in the spectral feature space (more details about choosing the right […]

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GIScourses2017

We’ve prepared a list of upcoming free online courses in GIS, remote sensing and other useful things. Below you can also find the courses that can be taken anytime. Feel free to add more links in the comments!   Data Analysis and Interpretation Specialization Data Management and Visualization Data Analysis Tools Machine Learning for Data […]

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parallelepiped-classification

The previous post was dedicated to picking the right supervised classification method. And this time we will look at how to perform supervised classification in ENVI. We will take parallelepiped classification as an example as it is mathematically the easiest algorithm. In ENVI working with any other type of supervised classification is very similar to […]

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supervised-classification

Image classification is a means of satellite imagery decryption, that is, identification and delineation of any objects on the imagery. Classification is an automated methods of decryption. The user does not need to digitize the objects manually, the software does is for them. According to the degree of user involvement, the classification algorithms are divided […]

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ft-mcmurray_

Like many others, we are fascinated by Google Timelapse. And decided to write a few words about this service and give a small digest of links reviewing it. On the 29th of November Google have announced the update to their Timelapse feature. Now everyone can travel in space-time, going back in time 32 years, up to […]

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sentinel-missions-nutshell

The European Space Agency is working on a family of satellite missions called the Sentinels. These missions are owned and managed by the EU as part of the Copernicus programme, that is said to be one of the most ambitious Earth observation programmes to date. It aims to give timely, accurate and accessible information for […]

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confusion-matrix

Applying any classification algorithm to interpret a remotely sensed image we are always interested in the result accuracy. The simplest way to assess it is the visual evaluation. Comparing the image with the results of its interpretation, we can see errors and roughly estimate their size. But if we need a reliable accuracy assessment, we […]

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thermal-cam

Among various types of the remote sensing, thermal surveying has a special place. First space thermography data was obtained back in the early 1960s by the sensors of the American TIROS satellites. Despite its low spatial resolution, this data showed a fundamental possibility of the usage of thermal imaging in remote sensing. The next years, […]

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scatter-plot-

There are different ways to illustrate objects’ spectral brightness variation when moving between different spectral ranges. If it has to be shown for a single pixel of an image or generalized for a group of pixels, then spectral brightness curves are used. And what has to be done when one wishes to display spectral characteristics […]

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