GIS and Remote Sensing Tools, Tips and more ..

Code sample to find point inside a polygon in shape file using GDAL/OGR 2.x and C#. using OSGeo.OGR; using OSGeo.OSR; using OSGeo.GDAL; 1: public void FindPolygonBelongsToPoint() 2: { 3: try 4: { 5: var shapePath = @"C:\Locations_WGS84.shp"; 6: Ogr.RegisterAll(); 7: OSGeo.OGR.Driver shapeDriver = Ogr.GetDriverByName("ESRI Shapefile"); 8: DataSource shape = shapeDriver.Open(shapePath, 0); 9: Layer layer = shape.GetLayerByIndex(0); 10: 11: Feature polygonFeature = layer.GetNextFeature(); 12: 13: long featureCountInLayer = layer.GetFeatureCount(1); 14: for (int i = 1; i <= featureCountInLayer; i++) { 15: 16: Geometry polygonGeom = polygonFeature.GetGeometryRef(); 17: 18: string coordinates = "POINT (-100.726 38.995)"; 19: 20: SpatialReference spatialRef = layer.GetSpatialRef(); ...

Dr. Roger Tomlinson has passed away. Tomlinson is generally recognized as the "father of GIS.” He is the visionary geographer who conceived and developed the first GIS for use by the Canada Land Inventory in the early 1960s.  This and continuing contributions led the Canadian government to give him its highest civilian award, the Order of Canada, in 2001.  Text for that award reads, “he pioneered its uses worldwide to collect, manage, and manipulate geographical data, changing the face of geography as a discipline.” Tomlinson tells the story of how this came to be.  In the early 1960s he was working as a photo interpreter for Spartan Air Services in Canada.  They had a contract to identify the best location for a tree plantation in Kenya.  They turned to their young geographer Tomlinson and asked him to develop a methodology.  He tried various manual methods for overlaying various environmental, cultural, and economic variables, but all were too costly....

Books Pro Cons It provides solid guide to how geospatial analysis work, particularly with respect to GIS. The book emphasizes conceptual workflows and with basic math which is helpful for creating own code and also getting an understanding of what's happening under the hood in contemporary GIS. It is better to have an update because lots of changes in GIS software over last five years. This book is for typical GIS user aspiring to design good maps. It is illustrating GIS map software and throughout with map samples in color which is especially useful for those who has little prior training or experience in map making. This is acceptable book for beginners but very little information of advanced users. It hardly touches on advanced cartographic representations. This book explains the computational geometry and algorithms concisely and very readable. It emphasis on describing algori...

pyKML   is an open source Python library for generating, parsing, and modifying   KML , the geo-spatial data language used by Google Earth, Google Maps and a number of other GIS platforms. pyKML helps working with large and complex KML documents by leveraging the use of basic programming constructs (looping, branching, etc.). In this regard pyKML is similar to   libkml , Google’s open source C++ library, but takes advantage of the highly readable syntax of the   Python   programming language and the processing capabilities of the popular   lxml   Python library. pyKML v0.1.0 documentation :  http://packages.python.org/pykml/ Source: Google Geo Developers Blog

Today, I was working on Shapefiles from Australia and Nepal for my biodiversity research. I found DIVA GIS is useful for the scientist and students who can't afford ESRI's ArcGIS suite. DIVA-GIS is particularly useful for mapping and analyzing biodiversity data, such as the distribution of species, or other 'point-distributions'. It reads and write standard data formats such as ESRI shapefiles, so interoperability is not a problem. DIVA-GIS runs on Windows and (with minor effort) on Mac OSX.

A highly ambitious project by Google, Google Earth Engine , will be launch by  the end of 2011. This project is using high resolution images from more than 30 earth observing satellites such as Landsat, MODIS,  IKONOS, QuicBird etc to build global archive of atmospheric corrected data sets.  According to Earth Engine team, these archives will be" available online with tools for scientists, independent researchers, and nations to mine this massive warehouse of data to detect changes, map trends and quantify differences on the earth's surface " in a cloud computing platform.  Currently, this project is in testing phase with limited  access to few groups of partner including CLASlite and IMAZON .  Let us wait and see how far they can go !!!

For my recent project, I have to display county wise time series data of disease pattern in web map for the conterminous United States for 20 years. In addition, I have to use Google maps as base layer and should overlay images on the top of it.  The concept sounds easy, and it was also similar with choropleth or thematic mapping . However, it should be in the Web 2.0. I tried to figure out what are the possible ways to achieve this, I tried and few of them. Here I am going to share the pros and cons of these methods in a real quick and dirty style. Choropleth with GFT 1) Google Fusion Tables Pros: Easy, No understanding of computer programming needed. Upload small or large data sets from spreadsheets or CSV files. Visualize your data on maps, timelines and charts. Pick who can access your data; hide parts of your data if needed. Merge data from multiple tables. Cons: Not much flexible and you can’t tweaks easily according to your needs.  Choropleth with Car...

Think, how powerful in geospatial technology? Finding Bin Laden using GIS?..........Are you kidding me? .......Take a look on this article from G ood politics  share the UCLA students' research on finding Bin Laden's possible hideouts using geographical theories and  GIS software. The students were work under Prof. Thomas Gillespie and John Agnew, UCLA, were published their findings in MIT International Review (Pdf ).