Viewing posts by Admire Nyakudya
Finding and fixing topology and geometry errors in QGIS
Google Maps, Google Earth, Uber are examples leading software/apps that are driven by GIS. They have allowed the ordinary person inadvertently to use GIS and appreciate its power without needing an understanding of the basics of GIS. Many people have taken the leap to using GIS by using some of the GIS capabilities in Google Earth.
Publishing digital elevation in Cesium
Digital elevation data is now readily available from multiple sources. There are several tools that can help to visualise elevation data, Cesium being one. Recently I have been researching how to visualise terrain data in cesium and I could not see a complete example that I could replicate on my own. This post will highlight the steps I took to visualise elevation data in cesium.
Calculating area of rasters in QGIS
QGIS raster functionality has come a long way and continues to improve. During my spare time, I am always on the lookout for interesting questions posed on https://gis.stackexchange.com.
Consuming cloud optimised GeoTIFFs in QGIS Server
QGIS has been able to consume cloud optimised GeoTIFFs (COGs) since v3.2, through the data source manager. This article does not aim to explain what a COG is as various other articles have done so extensively.
Create a custom reference grid in qgis composer part 2
This is a follow-up post on https://kartoza.com/en/blog/create-a-custom-reference-grid-in-qgis-composer/.
Data defined settings for grid placements in QGIS 3.12
For a while now I have been trying to simulate the 1in50k topographic maps of South Africa. I started using QGIS since version 1.8 and I couldn't replicate the cartography on the topographic maps but over time as QGIS has matured, I could replicate the NGI maps. NGI uses proprietary software and then Adobe to fine-tune some context on the maps. For this exercise I used QGIS 3.12.0
Calculating intersects for map layers and map extent dynamically in QGIS
Recently we have been working on a project that involves simulating the 1 in 50k topographic maps in South Africa. Since we are using QGIS Server to print the map all the logic is set up in print composer. All maps generated are dynamic (users can select a specific area within South Africa to print) and QGIS Server will use the map template to generate the map.
Batch count vector features intersecting series of blocks in PostgreSQL
The national mapping agency in South Africa (NGI ) caters for national mapping, digital topographic and other Geo-Spatial Information services. The department is mandated to provide spatial data for the whole country. In most cases, they have an in-house team that is responsible for digitizing aerial photography, field validation to produce vector data that is used to make 1:50 000 topographic maps.
Show only features within current Atlas feature - QGIS 3
In our endless endeavour to spread QGIS, I was invited to conduct QGIS training at the Surveyor General Department in Swaziland.
Mounting a storage drive in Hetzner cloud for rancher deployments
This article builds upon an earlier blog post by Tim Sutton on using-a-sambacifs-mount-as-a-docker-volume. In the previous article, Tim described the process of mounting a storage driver in detail.
Setting up geogig in a production environment
GIS practitioners and developers have long been interested in versioning spatial data. Luckily the folk at LocationTech have enabled us to do so through the provision of GeoGig (formerly geogit). Moreover, Geogig can interact with GeoServer seamlessly. At Kartoza we use Docker for orchestration of our services and as such it will form the backbone of this article.
Some QGIS 3 Browser Improvements - Small Things Matter
Well, QGIS 3 has been out for a couple of weeks now with lots of new functionality. While you are still feeling your way around all the new features I thought I could highlight some of the improvements to the browser panel that will make you fall further in love with QGIS.
An intern's perspective on her working experience at Kartoza during the summer vacation
As a leading Open Source GIS company, Kartoza aims to introduce people and organisations to the world of Open Source GIS in South Africa. The majority of educational institutions in South Africa still teach students GIS and Remote Sensing using proprietary software. During the last few years, there has been a steady increase in institutions migrating to using Open Source GIS systems.
Kartoza is always on the lookout for young and talented students to enroll them in our vacation work or internship program with a possibility of employment. The following story is the experience from our most recent intern, Natalia Dambe, a Master's Student at the University of Cape Town. In her words:
A new plugin to manage land (survey) parcels in QGIS
Kartoza releases the CoGo Plugin for QGIS
Kartoza recently published the CoGo Plugin (aka Parcel Plugin) in the QGIS plugin repository. This plugin expands the group of plugins designed to manage SDI (Spatial Data Infrastructure). CoGo ('coordinate geometry') refers to its ability to handle both types of coordinates used in land surveying, namely cartesian coordinates (x,y; long/lat) and polar coordinates (bearing and distance).
Changing the line direction of line features using the geometry generator in QGIS
I have been playing around with roads layers and wanted to change the line directions for some of my features. I looked around for solutions to do this in QGIS and saw that I could use the swap vector direction plugin in QGIS or ST_reverse in PostgreSQL. But I wanted to find a non destructive way to do this as I did not want to alter my data. I decided to try the geometry generator in QGIS.