Interactive Obesity and Rural Health Map

An interactive maps shows the influences of landscapes in rural health using ExtJs,GeoExt,Openlayers,Geoserver,PHP,Jquery, JavaScript, and other opensource tools.
Check it out

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Interactive West Nile virus incidence mapping using OpenGeo tools, Google APIs, & HTML5

The Geographic Information Science Center of Excellence at South Dakota State University developed a web based West Nile virus (WNV) mapping application using Geosever, Openlayers, PostGIS,GeoWebCache, Jquery, Google visualization APIs, and, other open source technologies. This application allows users to pan, and zoom to visualize historical WNV patterns while using a slider bar to navigate through time. Users can click on counties to see -county level time-series graphs, case counts, and total population. The application also supports changing choropleth transparencies, choropleth classifications, and map backgrounds.

Methods:

A. OpenGeo tools:

i.     Open layers

ii.    Geoserver

iii.   WebGeoCache

iv.   PostGIS

B. Google APIs

i.       Google Maps API

ii.      Google Charting API

C.      HTML5

These are frequently refereed to as HTML5 technologies.

Javascript

HTML Canvas

WebGL

CSS3

Other CSS improvements such as flex boxes

Offline Storage

Geolocation

New events such as touch and orientation

Ajax

Websockets

Click here to visit the Application

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CSS hack for Firefox/ IE compatibility

I really like Mike's hack for firefox/ IE compatibility and posted from his blog.

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How to connect spatial database(PostGIS) with QGIS?

In this section, I am showing the 3 basic steps to connect PostGIS database with a widely used open source desktop based gis, QGIS. 

Step1: Install PostGIS with Spatial database support extension

i.                    If PostgreSQL is already installed è Launch ‘Application stack builder’ from startup menu in windows 7.

ii.                  Select the appropriate instance of PGSQL from dropdown list and Click NEXT.

iii.                Expand ‘Categories’è Expand ‘Spatial Extensions’ è Select appropriate PostGIS version(1.5)  for the already installed PGSQL version(8.4).

iv.                    Follow the instructions to install the PostGIS extension.

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Solved: AutomationException 0x80004005 - Unspecified error

I was writing ArcGIS extension for Geoprocessing using JAVA and ArcObjects 10. My need was to process about 1000 PRISM raster datasets globally to compute various environments.

My application did work up to 45- 50 raster files without any problems in loop, then if fails with “AutomationException 0x80004005 - Unspecified error”. If I restarted the application again works for next 45-50 raster files and then crashes with the same error.

I still couldn’t figure out what was the exact cause for application failure-my guess is it may be due to memory management/garbage collection problem among ArcGIS COM objects and JAVA objects.

Fortunately, I solved this issue by reinitializing ArcGIS engine (hope re-initialization breaks the locks and flushes the garbage) after 20 raster files processing. Now, the application works well without any breaks but little bit slower while initializing the ArcGIS engine after 20 raster files processing.

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v.rast.stats - ERROR: No categories found in raster map

I was  experiencing "ERROR: No categories found in raster map" during v.rast.stats computation (Zonal statistics in terms of ESRI, ArcMap).

From the GRASS documentation, I learned that v.rast.stats is only designed for vector areas, not for lines, points,face,centroid,boundary, etc.

Therefore, I  unchecked all the properties of vector layer except area as in figure 2, and run the v.rast.stats- worked like charm..

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Interesting cheat sheets for R beginner

To clear the console: CTRL + L

To seek help: ?command_name

To view type:class(object_name)

To maximize the console print view: Options(max.print=999999)

To list active objects in R: ls()

To Remove single object:rm(object_name)

To Remove all Objects in R: rm(list=ls())

To remove all the objects - except 'a': rm(list = ls()[-a])

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An Interactive Visualization using Geoserver & Openlayers

From last couples of week, I have been involving to develop a interactive web interface for West Nile virus incidence dissemination across the conterminous US from 1999-2011.

The image on the right shows one of my accomplishment using
Geoserver,Openlayers,jQuery, PostgreGIS,and Google API. The project is about to launch online, then I will post a complete link of the project to let you guys play around it.

Click to visit: Web application

I am willing to help any one who is stuck with web maps/visualization and also seek constructive criticism on web stuffs.

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An introduction to Opensource GIS and Geoserver

Open Source software has come a long way in recent years for storing, manipulating and presenting spatial data. The Openstreetmap (www.openstreetmap.org) project is a great example of what can be achieved using open software and open data.

This presentation will look at using a combination of postgis, geoserver and openlayers to process, store and present vector and raster map data.

The presentation will also demonstrate OGC web mapping protocols, map projections, spatial toolkits (including uDig, gdal and ogr) and sources of free geospatial data.


Gavin Jackson is a software engineer working in the Spatial Team on the Atlas of Living Australia project (www.ala.org.au).

Bio: A software engineer with 10 years experience (BInfTech ANU, Msc UNSW), he has worked in a variety of environments, including Department of Defence (IT Security), CPT Global (Stress and Volume Testing), Les Mills (Software Engineer) and, currently, CSIRO (Spatial Software Engineer). 

He has long been an advocate for the use and implementation of Open Source technologies, and is a Redhat Certified Engineer (RHCE).

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MODIS Data Products Naming Convention

Are you wondering on MODIS products' naming convention? Don't worry !!. This is the time to dig out MODIS names. Let's say you have few MODIS products.


Nadir BRDF-Adjusted Reflectance (NBAR): MCD43B4.A2000185.h25v03.005.2006299173851.hdf


MODIS Land Surface Temperature Products: MOD11A2.A2002241.h12v02.005.2007222102136.hdf



MCD43B4 or MOD11A2- MODIS Product Short Name




A2000185 or A2002241 - Julian Date of Acquisition (A-YYYYDDD)




h25v03 or h12v02- Tile Identifier (Tile location- horizontalXXverticalYY)




005 - Collection Version




2006299173851 or 2007222102136- Julian Date of Production (YYYYDDDHHMMSS)


The YYYYDDD of above products equivalent to 2006299 and 2007222, which means Year:2006 Day of Year:299 (OCT 25, 2006) & Year:2007 Day of Year:222(AUG 09,2007)




hdf - Data Format (HDF-EOS)


Cheers !!

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