Tutorials

Accuracy Assessment in Image Classification on GEE

Accuracy Assessment in Image Classification on GEE

This post covers accuracy assessment on a sentinel image in the Google Earth Engine. Selection of the area of interest and the classification classes This is done using the geometry tool as shown below. One can use the point tool or the polygon tool in the selection of the classes. Selection of the Image collection…

Computation of NDVI using Google Earth Engine

Computation of NDVI using Google Earth Engine

Normalized Difference Vegetation Index (NDVI) is a spectral index used to quantify the greenness of vegetation. It is used to monitor the health of plants and understand vegetation density. Calculating NDVI is done using two bands: the red band and the near-infrared band. This computation can be easily adapted using the Google earth engine. This…

Unsupervised Classification in the Google Earth Engine

Unsupervised Classification in the Google Earth Engine

This blog covers unsupervised classification in the Google earth engine. Source: Google Earth Engine The process of unsupervised classification in GEE is carried out using  the ee.Clusterer package. The package has been adopted from Weka Loading of the image The image used in classification is from the landsat program. A landsat 7 image is used…

Supervised classification in GEE

Supervised classification in GEE

In this post, we will cover the use of machine learning algorithms to carry out supervised classification. Source: Google earth engine developers Supervised classification is enabled through the use of classifiers, which include: Random Forest, Naïve-Bayes, cart, and support vector machines. The procedure for supervised classification is as follows: Selection of the image The first…

GeoDjango Tutorial Guide

GeoDjango Tutorial Guide

Some months ago, I was requested to develop a written guide on web-mapping system development using GeoDjango as published on the playlist on My Channel . After great efforts, I have released a complete GeoDjango guide that serves as a written replica of the YouTube Playlist. The guide illustrates the possibilities of developing a fully-fledged…

Using Photos in QGIS Projects

Using Photos in QGIS Projects

In QGIS, there are many formats of data-sets that can be used. Joins and relates help users get the best out of their data depending on the users’ needs. These tools exist out of-the-box for use by everyone. However, there are some tools or functionalities that are tricky to use as they don’t appear straightforward…

Filter Data into separate layers in Leaflet

Filter Data into separate layers in Leaflet

Data loaded in Leaflet as a layer can be filtered on the fly to create separate layers that meet a certain criteria. This is very helpful when handling data that is not too huge for the browser. I have a done a video tutorial to demonstrate how to filter data on-the-fly in Leaflet. This tutorial…

3D Maps with Leaflet and eegeo.js

3D Maps with Leaflet and eegeo.js

We like maps and will continue like them more. Every day, there are changes in the libraries used for mapping. With most maps being 2D, exploring 3D maps is so much fun and better. In this post, I describe a procedure to display 3D maps for your web mapping project. First, we will have a…

Nearest neighbor Analysis in QGIS

Nearest neighbor Analysis in QGIS

GIS is very useful in analyzing spatial relationship between features.It is important at times to find the features nearest to a feature in GIS.To achieve this, we can use the Distance Matrix that helps in calculating the distances between each point in the dataset. Steps You can use Vector > Analysis Tools > Distance Matrix,…

3D visualization of Data in QGIS

3D visualization of Data in QGIS

Well, this is a topic that I have always wanted to write about but have been a little bit reluctant.I think this has been attributed to the fact that I didn’t find people who wanted to use this feature.Last week, I found someone who really wanted this in their project.Here is the thing, if you…

Using QGIS Layer Styles in GeoServer

Using QGIS Layer Styles in GeoServer

GeoServer provides us with the functionality of styling our layers to match our preferences. However, many are the times that many GeoServer users face problems while publishing their layers. Styling in GeoServer should be an easy task when doing web applications or publishing your GIS layers via GeoServer. Today, I will focus on how to…

Generating Contours from  DEM in QGIS

Generating Contours from DEM in QGIS

      A few weeks ago I wrote a post on “Generating DEMs from Contours” which was quite a straight forward process as explained.In this post , I will show how to “reverse engineer” the process and generate contours from DEMs. This time round am also going to demonstrate how to clip our dataset to work…