TagMac

Trying out new GIS software

I want to draw 50 and 120 feet buffers around the points of store entrances to show where bike parking should and shouldn’t be installed. I want to follow this example:

walgreens with bike parking buffers

Aerial photo of a Tucson, Arizona, Walgreens showing the location of existing bike parking and two buffers (50 and 120 feet) where proposed city rules would allow bike parking. I advocate for ratifying the 50 feet rule, which I’ve discussed on this blog and elsewhere many times.

I want to do this easily and accurately, so I will use GIS software to create a “buffer.” I use QGIS occasionally, but I want to try out other Mac-friendly applications. I’m getting my orthoimagery (geometrically corrected aerial photography) from the United States Geological Survey (USGS) using a web protocol called Web Map Server. I’m trying:

  • Cartographica, $495, with free trial license.
  • uDig, completely free software. UPDATE: I have had NO success getting any data to load from a WMS connection into uDig. I would like to understand why. Cartographica can obtain some of the WMS-stored data I want, although it messes up often.

I’m having success with neither – both are having issues downloading or maintaining a connection to the USGS orthoimagery. In one case, Cartographica trims the Bing Maps imagery to match the extent of my other objects (the buffer). In another case, it won’t even download the USGS imagery (and gives no indication that anything is happening). uDig hasn’t been able to download anything so far – I hope it’s asking for the current extent, instead of all data because it’s taking a looong time to do anything (so long that I just quit in the  middle of it).

This screenshot shows how to add new WMS connections to Cartographica.

UPDATE: I did it! I successfully used Cartographica (and the integrated Bing Maps) to create this drawing that shows the current (abysmal) bike parking at a Chicago Home Depot outside the 50 feet line.

Geocoding in Quantum GIS – QGIS

Geocoding is the process of turning street addresses into geographic coordinates. You can geocode easily in QGIS using several methods.

If you just want to geocode and you don’t need to see the addresses plotted on a map in QGIS, then follow these instructions. If you don’t need to see them on a map nor do you need the geographic coordinates, then use BatchGeocode.

If you only need to geocode a single address and get its coordinates immediately, use geocoder.us.

An example geocoded address on the map using the “single address” method.

How to geocode multiple addresses in QGIS

UPDATE April 11, 2013: Updated the directions because the “Add delimited text layer” function moved from the Plugins to Layer menu. 

UPDATE March 24, 2011: I updated the directions to use GPS Visualizer instead of BatchGeocode.com because BG stopped giving geographic coordinates in its output.

Get directions on geocoding a single address in QGIS with a plugin.

QGIS is an open-source Geographic Information Systems (GIS) application that has been gaining ground since 2004. It runs on all operating systems (it began as a Linux project) and you can download it for free.

I use it often because ESRI doesn’t make the popular ArcGIS software for Mac. That’s unfortunate, but like I said here, software, technology and mapping issues can be easily overcome – we can use QGIS to create maps. QGIS, though, is missing one major feature for basic map building: geocoding.

Here’s a step-by-step tutorial on how to bring in multiple street addresses and their XY coordinates into your QGIS map en masse: Continue reading

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