In a recent project I needed to determine the perpendicular distance from a single point (C) to a line created by two other points (A and B). Nor...
What are H3 grids? Created by Uber Engineering, the H3 grid system divides the Earth’s surface into a hierarchical...
Update 2024-01-05: Added steps for saving a geojson file from pgAdmin....
This is a talk I gave at the 2021 Ohio GIS Conference. It outlines an open source pipeline for creating Cloud Optimized GeoTIFFs and raster tiles f...
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This talk describes the slow and painful migration from a legacy GIS data structure of hundreds of shapefiles to a modern setup using a mix of Post...
In the aftermath of the Coronavirus pandemic, remote work may well be come the new normal, as businesses and government agencies discover that prod...
Update 2023-09-19: I added support for decoding domain values and npx - so you can run the tool straight from the command line. Here’s a ...
Update: This visualization is no longer being updated. There are a wide variety of authoritative COVID-19 trackers on the internet, including o...
In my day job we recently completed a project to field locate our water utility assets using a high-accuracy GPS unit. Now that this data is online...
Creating a hover effect is a great way to add interactivity to web maps. In mapbox-gl there are two main methods to accomplish this feature: ...
A primary focus of my day job is managing utility datasets for a small municipality. I am currently in the process of taking a simple database of l...
The GitHub repository with all the code needed to follow along with this presentation can be found at ...
The Open Parcel Viewer is a client-side application written in plain javascript and jquery. It is capable of rendering up to 50k polygons on deskto...
This simple, responsive store locator is based on the original Mapbox JS exampl...
This presentation was given at the 2018 Ohio GIS Conference. The NodeJS example is hard-coded from a real-world example in the original presentatio...
The goal of my original post on client-side web mapping for large datasets was ...
This presentation was given at the Northeast Ohio GIS Sympoisum on August 25, 2016. The primary objective was to give an overview of using ...
Update 2017-08-01 This app has seen two more iterations. These each utilize an mbtiles-server to host the vector tiles, but still use client-si...
The maps above use the same data set, visualized using four different map types in the CartoDB web interface...
This is my take on a more modern looking leaflet toolbar/ui. With leaflet-search as t...
One of the benefits of using the open source Leaflet mapping library is the wide variety of available community supported plugins. This simple map ...
Update: This map originally used Google’s Picasa Web API, but this will soon be shut down...
This is a quick look at Leaflet, Google MyMaps and Esri’s ArcGIS Online....
Here I explain how to create a raster catalog in order to have a mosaic of a set of images. This way you can always add or change the images instea...
One of the clients I work with utilizes unmanaged raster catalogs as part of their work flow. We manage over 20 raster catalogs with close to 4gb o...
This video shows the growth of urban infrastructure from 1850 (blue) through to the present (red). I utilized the time/timeslider/export video feat...
This little trick came from GIS stack exchange. To run a model using only selected features, open your model and in the model builder window right ...
