GIS and Remote Sensing Tools, Tips and more ..

Import the following references in the project. using ESRI.ArcGIS.Geoprocessor; using ESRI.ArcGIS.SpatialAnalystTools; using ESRI.ArcGIS.esriSystem; This solution is only works for single band raster. For multi-band raster zonal statistics I will make a separate post soon. public static void ComputeZonalStatisticsFromEsri(string feature, string zoneField, string valueRaster, string outputTable) { ESRI.ArcGIS.RuntimeManager.Bind(ESRI.ArcGIS.ProductCode.Desktop); ESRI.ArcGIS.RuntimeManager.BindLicense(ESRI.ArcGIS.ProductCode.Desktop); UID pUid = new UIDClass(); pUid.Value = "esriSpatialAnalystUI.SAExtension"; // Add Spatial Analyst extension to the license manager. object v = null; IExtensionManagerAdmin extensionManagerAdmin = new ExtensionManagerClass(); extensionManagerAdmin.AddExtension(pUid, ref v); // Enable the license. IExtensionManager extensionMana...

If you are creating a new project- set up GDAL & C# environment as described  here Code Snippet: Read raster block by block using GDAL and C# private static void ReadRasterBlocks(ref Dataset valueRaster) { Band bandValueRaster = valueRaster.GetRasterBand(1); int rasterRows = valueRaster.RasterYSize; int rasterCols = valueRaster.RasterXSize; const int blockSize = 1024; for(int row=0; row<rasterRows; row += blockSize) { int rowProcess; if(row + blockSize < rasterRows) { rowProcess = blockSize; } else { rowProcess = rasterRows - row; }

This will be a series of videos on Programming with ArcObjects by Hussein Nasser  where he features a fictional project called Bestaurants and gradually added functions to the project from scratch using ArcObjects and Vb.NET programming on top of ArcGIS. An excellent tutorial for beginners to learn how to use ArcObjects to build an ArcGIS application.

If you are creating a new project- set up GDAL & C# environment as described  here Code snippet: Read raster into an Array using GDAL and C# //Register all drivers Gdal.AllRegister(); //Read dataset Dataset rasterDataset = Gdal.Open("rasterName.tif", Access.GA_ReadOnly); if (rasterDataset == null) { Console.WriteLine("Unable to read input raster.."); System.Environment.Exit(-1); } //raster bands int bandCount = rasterDataset.RasterCount; if (bandCount > 1) { Console.WriteLine("Input error, please provide single band raster image only.."); System.Environment.Exit(-1); }

Import ArcGIS.ConversionTools and ArcGIS.Geoprocessor then pass the file paths as param into following function you will get the resulting raster out of shapefile. using ESRI.ArcGIS.ConversionTools; using ESRI.ArcGIS.Geoprocessor; public static void Rasterize(string inputFeature, string outRaster, string fieldName, int cellSize) { //Runtime manager to find the ESRI product installed in the system ESRI.ArcGIS.RuntimeManager.Bind(ESRI.ArcGIS.ProductCode.Desktop); Geoprocessor geoprocessor = new Geoprocessor(); geoprocessor.OverwriteOutput = true; FeatureToRaster featureToRaster = new FeatureToRaster(); featureToRaster.cell_size = cellSize; featureToRaster.in_features = inputFeature; featureToRaster.out_raster = outRaster; featureToRaster.field = fieldName; geoprocessor.Execute(featureToRaster, null); }

Over the week, I stumbled on problem clipping raster with feature using C# and Gdal and come up with following solution, which clips the features and fills no data value for missing raster  values inside the extent. If you are creating a new project- set up GDAL & C# environment as described  here

Last week I have installed PostgreSql/PostGis and PgAdmin. Once I have tired to import shape file from PgAdmin using "PostGIS Shape file and DBF Loader 2.1" as below. But it throws an error complaining "File import error in PostGis AddGeometry column doesn't exist" as shown in figure below  Then, I found out that the spatial extension is not enabled in my database. The following image shows the steps to enabled the spatial extension in the database.  Open new extension and name it postgis.   Then import the shape file again... Voila it works

In few months the MesoWest group will depreciated their MesoWest data API version 1 and fully moving over version 2. The Meso West data API 2 have been in the production for most of this year. The API v2 has significantly faster and more useful than version 1 and well as increased response time and availability including accumulated precipitation, simple station statistics, and climatological data requests. Here is the code snippet to extract data variables using jQuery in JSON format.  $.getJSON('http://api.mesowest.net/v2/stations/nearesttime?callback=?', { state:'ca', county:'Los Angeles,San Diego,', latestobs:1, status:'active', token:'API_TOKEN_PROVIDED_BY_MESOWEST_GROUP', within:15, //Observations with in past 15 min vars:'air_temp,relative_humidity,wind_speed,wind_direction', obtimezone:'local' }, ...

I have been working on a .Net based project that requires feature to raster conversion without using ESRI ArcObjects. The GDAL seem's an obvious solution to us and wrote a small snippet for rasterize layer using Gdal and C#. Hope it will help someone someday... Step 1: Setup the environmental variables for GDAL  Setup the environment as described in   Getting Started with C# and GDAL OR  (Copied here for future reference - ) Getting started with C# and GDAL The Geospatial Data Abstraction Library (GDAL) is great if you want to process raster data, especially regarding format conversion. I want to use GDAL for a biodiversity modelling project, so I had a look at the C#-bindings of GDAL. The described steps work both with VS 2010 as well as VS 2012, what you need to do is: Download the latest version of the precompiled GDAL binaries from  here . Choose the ones that suit your system (32bit or 64bit). Extract the contents from the zip file ...