Thursday, August 29, 2019
Remote Sensing Report Essay Example | Topics and Well Written Essays - 1750 words
Remote Sensing Report - Essay Example The NDVI varies from -1.0 to 1.0 for every pixel in a representation and is vital in discovering regions of ranging levels of plant biomass/dynamism. This means that higher values symbolize high biomass/dynamism. The vegetation indices normally depend on the actuality that green vegetation indicates an authentic combination of low reflectance at perceptible red wavelengths and elevated reflectance at near infrared wavelengths. In similar manner, a ratio of close to infrared (NIR) by red à ® light will issue out an approximation (RVI) of the amount of green vegetation present in every pixel. These therefore may be computed as follows: RVI=NIR/R This ratio is well known as the ââ¬Å"Ratio Vegetation Indexâ⬠thus the notion RVI. The ultimate aim of this report is to examine how the ratio vegetation index is computed using Lake Nakuru in Kenya as example. It also looks at the unsupervised and supervised classification and examines their advantages and disadvantages. Part 1: Vegeta tion Indices Methodology The methodology used in this research is a fieldwork quantitative analysis carried out on the vegetation structure of Lake Nakuru. The ratio vegetation index is calculated where all the steps involved are indicated. Quantitative analysis is one of the best fieldwork methodologies that provide accurate results that are reliable in conclusions and decision-making processes. Analytical Steps The steps for calculating the ration vegetation index are as follows The first step is calculating a ration vegetation index from Landsat TM Data This means that the computed ratio vegetation index (RVI) for the Nakuru Thematic Mapper (TM) representation. For Landsat Thematic Mapper data, the band 3 gauges red, light as TM band 4 gauges near infrared. Lake Nakuru is a little shallow alkaline lake situated south of Nakuru town in Kenya. It is a small lake but it is the worldââ¬â¢s most famous place where the greatest bird sight on earth. It is where more than one million pink flamingos gather to the lake to eat the excessive algae, which flourishes in the warm waters of the lake (Jones, Settle and Wyatt, 2006). Scientific scholars have approximated that the population of the flamingos at Lake Nakuru uses about 250, 000 kg of algae per hectare of surface area every year. However, it is not only the flamingos found at Lake Nakuru although they are the most abundant; Pelicans and cormorants are also present in large numbers. In reality, Lake Nakuru is actually a home for more than 400 different species of birds, which means that it is the leading place with variety of bird species than any other place in the country. The second step is adding color to the Ratio Vegetation Index representation (Bonner, Rohde and Miller, 2001). This is done through reloading the Nakuru image although this time one clicks on the raster options tab to add dialog and show as a pseudo color image. Then select raster/Attributes on the viewer menu bar for Nakuru-rvi.img. The f ollowing raster editor should be displayed Select edit/colors from the Attribute Editor Menu. The following color Editor should be displayed: From this color tab, try changing different colors at the start and end colors, and choose the Apply button. The Nakuru-rvi.img representation has to change color. Try
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