GeoSpatial Knowledge Hive

Scientist who want to study gravity can take help of GIS & Remote Sensing  Image by  mohamed Hassan  from  Pixabay   Which data set to use : Grace What it does:  It makes Detailed measurement of earth's gravity Investigates about Earth's hydro reservoir  Investigates physical changes earth encounters  Investigates Disasters Official site:   http://grace.jpl.nasa.gov/ image source: http://grace.jpl.nasa.gov/

China launches world largest telescope "Five-hundred-meter Aperture Spherical Telescope, or FAST" Investment :   $180 million Importance : Research, military, Space Control Research Area :  Tracing sign of intelligent extraterrestrial life.  Detecting gravitational waves.  Detecting radio emissions from stars and galaxies. image source: http://www.nydailynews.com/

Using Python to capitalize strings  - Add new field in Attribute Table - Go to Field Calculator  - Select Python  - use         .title()       .upper()       .lower() title= Abc upper= ABC lower = abc  Example=  FieldName.title() Image Source: Pixabay

Radiometric Resolution  is defined as magnitude of EM ( Electromagnetic Energy ) recorded by a sensor Units : Measured in Bits Formula: Each bit records an exponent Power of 2. 1 Bit= 2 2 Bit=4 4 Bit =16 8 Bit=255 digital values Note: 0 represents Black tone and maximum like 255 represents highest tone. image source  www.satimagingcorp.com 1 Bit will be Black & white 16 Bit will be colored 32 Bit will be more colored and will carry greater energy levels Higher Radiometric Resolution much variation in colors reflected. Image to left is of  higher radiometric resolution than that of Landsat below. image source: geoinfo.amu.edu.pl

Free Remote Sensing Software OSSIM Open Source Software Image Map What about OSSIM : Open Source Remote Sensing Software  Who Funds : US departments (Intelligence & Defense) Image Source: Pixabay  Specialty: Supports more than 100 Raster & Vector Formats, Plugin Option available  Suitable for: High resolution Imagery (Spatial) OSSIM APPS:  Command Line  Desktop Applications     What OSSIM say about itself:                                                                                                      Image Source:http://trac.osgeo.org/ossim/wiki Image Source:http://trac.osgeo.org/ossim/wiki

Visualize View From a Particular Point Using GIS  How many places are visible from your point, e.g. you want to construct a house how many places are visible from that sight.e.g. you want to practice shooting , how many visible spots can be shot from location (A Military Application)...likewise many other interesting applications can be performed using viewshed analysis. Image by  Tim Hill  from  Pixabay Performing ViewShed Analysis   Use any GIS software, e.g. i will use ArcMap, as a first step get data set of your area. DEM (Digital Elevation Model) that gives topographic information (lat, long, height) freely available online. A shapefile of your point of sight, which you can create it easily in GIS software Example :   plne , an elevation grid; and lookouts.shp , a lookout location shapefile. Step-1 : Start ArcMap , Add data  Search for Hillshade  and  specify  files plne or your grid file  Hillshade Tool...

Lidar Data is available free of cost  How it works: User generated data sets that are registered  Good Point:  Free LiDar data   Open Topograhy Tools and Softwares  Point2Grid Opal ToolKit myHadoop For more research about Open topography visit:   http://www.opentopography.org/

Maptitude is a low cost commercial GIS software solution. What it used for: Higher level spatial analysis  Example: Geo-scientific, Environmental, Demographic   What are its Competitors:  SAGA GIS, QGIS and Esri ArcGIS  image sourcce: http://www.geo-matching.com/ Interesting  Features: -  3D Rendering  -  Loaded with Data set (transportation, demographic and many more) -  Good for Vehicle Management Applications (Routing) -  Beautiful Visualization   Purchasing a commercial GIS Software, maptitude is also one option.  Want to know more about it: Geo Matching explains in detail Click here   for more details. 

Perform Geocoding Use google Earth search any place, & save the KML layer result by right clicking. Open ArcMap , convert saved KML to ArcGIS Layer using " KML to Layer " tool,  Add new layer. Add Base Map, thereafter export layer to shapefile . image source:  google-earth.en. image source:  www.arkzoft.net    

Have you imagined how satellites have surrounded earth surface  Click   ESRI satellite Map  which beautifully visualizes all satellites surrounding earth. Image Source: ESRI Satellite Map

T  his tutorial explains steps to generate 3D surface for visualization and analysis. Image by  lijunzhuang  from  Pixabay         Start ArcScene from start menu.       Add DEM layers        Go to properties        Choose Base Heights tab.       Click   Obtain heights for layer from surface       Click Ok  Image Source: 3D visualization        

Science of measuring shape and forces of earth. GIS needs Geodesic concepts to determine accurate positioning. Datum we use in GIS are core of Geodesy. Image by  Paul Brennan  from  Pixabay  

DigitalGlobe Free Product Samples What is the Resolution of sample imagery: You can almost see license plates with the 30 cm spatial resolution data from the newly launched Worldview-3 satellite. Download 30 cm product: Image source: http://www.digitalglobe.com/

Free Remote sensing Software   Why so special : Free and Open Source   Additional Features: Extendable Plugins, an open source option to ERDAS IMAGINE, RemoteView, ENVI, or SOCET GXP, What Opticks say about its features:                        image source: opticks.org Free and open source Supports the following file formats: NITF 2.0/2.1, GeoTIFF, ENVI, ASPAM/PAR, CGM, DTED, Generic RAW, ESRI Shapefile, HDF5, AVI, MPEG, JPEG, GIF, PNG, BMP Zoom, pan, rotate spatially large datasets Quickly layer GIS features, annotations, results, and other information over your data to provide context Many image display controls such as colormap, histogram, transparency, etc. Support for datasets larger than four gigabytes Analysts can quickly combine steps using graphical wizards Support for processing data in its native interleave of BIP, BSQ or BIL Get  extensions  to drop in new capabili...

Assigning  image  to behave as real earth position with true coordinates(lat, long) defines all three terms but there are differences. Geo-Referencing is general term that assigns a topo sheet true coordinates. Image Registration  is assigning an image coordinates on basis of another image. It is usually an image to image Georeferencing. Image Rectification  is assigning an image coordinates on basis of another vector data or shapefile or map. Share your thoughts by commenting below. Image by Free-Photos from Pixabay

What is Vector Data Model? Vector Data model is important concept in GIS, It consists of   point line and polygon features . Image by  Gerd Altmann  from  Pixabay   Point:   features recorded as single x, y coordinate pairs or geographic location imagesource:  www.mapwindow.org Line : features are an ordered series of connected line segments image source:  gis.stackexchange.com Polygon : Features are an ordered series of at least 3 connected lines with same start and end point. Image source: ArcMap Window 

Many times you need to see how a terrain is changing in terms of slope over certain area, in GIS terms a slope is defined as  rise/run is defined as  Maximum rate of change in elevation over distance  between  cell and its eight neighbors .  Image by Elias Sch. from Pixabay Data you need: A DEM of your area easily available over internet  Start   Arccatalog ArcCatalog Window  Make Connection to Folder containing Data Set by right click on Folder Connections   at top left tab “ Folder Connections ”.     Launch Arc Map Tool Interface     Right Click Layer and select Add Data -> Add “gridfile.txt” or DEM  Click on the search icon (Ctrl+F) Ascii To Raster Tool  Using local search . Type “ ASCII to raster ” in the dialog box.  Click on function ASCII to Raster (Conversi...