GIS & Remote Sensing

This article in continuation of earlier article on downloading and processing of Cartosat DEM. https://www.gisoutlook.com/2020/08/download-cartosat-dem-through-bhuvan.html In this article, processing of DEM is explained such as re-project, clip and fill the Gaps and remove error present in DEM. These correction can be performed using GIS functions . Reprojection is needed for correcting geometric errors present in DEM as well as convert projection system one to another.  GIS tools can be used for Clipping of DEM is very important especially for watershed delineation, for this clipping boundary based on study will be used. Error present in DEM is defined as sudden extreme high  and low  values occur in comparison to surrounding values.   Step 1 –  Re-project the mosaic DEM using QGIS Here we will change the CRS from Geographic to UTM. For this click on Raster then Projections followed by Warp (Reproject) . Warp (Reproject) window will popup. Here define Input layer and Target C

Cartosat DEM Download and Mosaicing Process using QGIS This article is prepared to discuss steps to download Cartosat DEM through bhuvan portal . As this DEM downloaded in tiles so one may need more than one DEM tile for study area.  Therefore it is necessary to mosaic these tiles to make a single tile of DEM. In this steps of both processes- download and mosaic are shared to create DEM, which can be further used further for different remote sensing and GIS based applications. Such as  Agricultural Studies Wetland studies Watershed Studies Runoff and Sediment Discharge Studies Urban Sprawl Mapping Transport Studies etc. Step 1 -  Download freely available DEM data using NRSC-Bhuvan website Open weblink:  http://bhuvan.nrsc.gov.in/bhuvan_links.php From this page go to top menu option –  Open Data Archive A new window will open after clicking on Open data Archive. You need to make user id on this page, so click to  Login (on the extreme top right corner) Aft

Spatial data can be manages and analyzed using GIS. In current, GIS application is increased in transportation studies especially in planning and management. Public transport system is an important part to manage and plan for urban development.  Public transport symbolizes as an efficient mode to travel by the people for different purposes in the specific region with the less impact on the environment .  Therefore urban planners and decision makers need to identify useful approach to deal with resistance of people to travel by public transport. It is become important to evaluate and identify the areas which are poorly connected with public transport system but at the same time those areas need to provide public transportation due to availability of high rate of potential users. Public transport system is accessed through its stop/station, so it is important to know and estimate coverage area of stop/station. The coverage area is significant for public transport that the increase i

Remote Sensing process is very significant to keep watch on earth surface features including both man-made and natural. Satellite image acquired and processed in image processing software to create spatial data. These spatial data can be further used as input data in different mathematical models to analyze the change and to find trends in future for policy planning and implementation. GIS software also used to create input data and those spatial data can further integrated in models to analyze current as well as future scenario. GIS has many functions and tools which can be employ to find the impact in that area as well as to analysis impact of neighborhood or vice versa.   In this scenario analysis, the urban area has been re-simulated for 2015 and 2025 by including commercial and industrial areas proposed in the 2025 land use plan. The aim of this analysis is to ascertain the impacts of commercial and industrial areas on urban change . The variable proximity to commerci

This article is in continuation of last article in which remote sensing and GIS used for spatial analysis to assess and prospects of future scenario in urban change. In the below article another case is discussed in which effectiveness of proposed plan of 2025 for city is assessed using remote sensing and GIS based spatial analysis process. Through remote sensing , one can acquire satellite image of different periods or multi date as well as from high resolution to medium resolution and also combination of bands or multi spectral or panchromatic band.  In current there are many choices are available related to acquiring of satellite images . This may help user to create spatial data from high resolution to medium resolution as per need and also for different periods like from last 10 or 20 years to ascertain the change and trend of urban sprawl .  The basic and important steps of digital image processing such as layer stacking , subset , mosaic , enhancement , interpretat

Remote Sensing data or images can be used to assess past trends and current status of natural as well as man-made features on earth surface. Satellite images can be acquired based on need and using image characteristic/properties such as Spatial, temporal and spectral resolutions to create spatial data in the form of land use/land cover maps.  GIS is used to create other spatial data such as road network, proximity to central business district etc.  The spatial data can be created in both raster and vector format including non-spatial data in the form of attributes for scenario based analysis.  These data can also convert from raster to vector and vice versa as per need using image processing and GIS software .  These spatial data can be integrated to assess the changes in future based on some specific condition and constraints.  As GIS allow to incorporating mathematical and simulation models , it is become easy to use these spatial data for assessment based on certain cond