GIS and Remote Sensing Tools, Tips and more ..

I was checking the route for nearest police station from my office around 3 PM MT using the Chrome. The  Google Map's street looks so funny and floppy. All the street lines and highways lines were wiped out. The interstate has some brown points, if you zoom in them the point looks like half circle. Which has the bug Google Maps or Chrome? Click on images for bigger picture ! (Missing roads)                                                                  (Missing roads on zoom)                                                                          (More zoom in...) (Looks good in  the Firefox though)

Finally on Nov 19 2013, Google shut down Google Maps v2 API, which was depreciated in May 19 2010 but was working continuously Nov 19. I was aware of version depreciation, but I procrastinate to upgrade till last minute because of working on too many other things. While checking my Web map (built on Openlayers, Geoserver and Google Maps as base layers (Google Maps API v2) on Nov 20, I saw two map controls one from Openlayers and other from Google Maps API also noticed that map application was unresponsive. Looking around I found easy steps to fix it without major change in the code-

Abstract Analyzing space-time variation is common in Geography. Appropriate geo-spatial visualization enables us to understand data in a precise manner. There have been numerous researches, tools, and methods in pursuit of a better visualization method for geospatial data. Here we present the sets of examples developed by us to show the benefits of the web cartography using Google Earth/Google Maps mashups to display geospatial data. Moreover, we include the practical implication of applications that are useful for visualizing geospatial world.

“ This book is an attempt to share the knowledge I've gained from the experts at Google. When I joined it, the KML team consisted of two engineers: Bent Hagemark and Michael Ashbridge ("Mash"). Bent and Mash's mission was to corral the existing KML into a formal XML schema, to create compelling examples that would represent good coding style, and to shepherd the language to its new and deserved status as an international standard. I was to create a website for KML and expand the existing documentation. I managed to complete that task, but it always felt as though I'd exposed only the tip of the iceberg. Well, here's The Iceberg.”          – Author "KML Handbook :Geographic Visualization for the Web" is primarily targeted for people who are curious about how to create customized presentations for an Earth browser such as Google Earth but have little or no experience with computer programming. It has step by step guidelines to create...

Creating a kmz image overlay  1. Make sure the dataset you are working with has a geographic coordinate system (unprojected) with WGS84 as the datum. If not, you will need to reproject your data. If the coordinate system of your datasets is defined you can change the projection “on-the-fly”. To reproject on-the-fly, go to Layers then Click Properties and specify geographic with WGS84 datum as the coordinate system. However, I recommend reprojecting the actual GIS datasets (shapefiles, grids, etc.) because project-on-the-fly is not always very precise, particularly when dealing with datum transformations. 2. Switch to the layout view. Select a layout that matches the dimensions of your map as closely as possible. To keep the file sizes of your images small, try to leave as little empty space around the edges as possible. Right-click on the layout and select Page and Print Setup to change the layout size. 3. Right-click on the map and select Properties. Go to the Size and Posit...

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 !!!

From last couple of days I was busy on Google custom styling like  http://maps-api-tt.appspot.com/apilite/styled/styled.html  . Fortunately, I found a good tutorial to share to carry out such custom styling. Check it out @ bestfromgoogle  

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...