Friday, September 30, 2005

Daytime vs. Nighttime Population Counts

The daytime and nighttime population counts in Dallas vary a great deal. The population is much higher in the daytime, and drops to almost nothing at night.

In the past, I have steered users interested in distinguishing between day/night counts to the Zipcode Business Patterns as this provides the number of employees per zip code. However, a Landscape Architecture professor and some of his assistants need these counts on the block group level. I know of no freely available resource, so we turned to the AGS (Applied Geographic Solutions) BusinessCounts Daytime Population product.

This product is not the cheapest, but it is manageable. However, Spatial Insights offers a product called AGS Premium, which provides steep discounts for AGS data if bought in this premium package. The discounts are so cheap, that we went ahead and purchased the AGS Premium package.

I am now anxiously waiting for the data to arrive.... Just like this day, nothing makes me happier at work than accessing a new package of bright & shiny datasets.

Another GIS Library Blog...

It is wonderful not to be alone in the universe....

This is by no means a new blog, but I just came across today "'Compass: A place for the exchange of ideas and news on GIS and Maps at George Mason University."

This blog is created by the Government Documents and Maps department of Fenwick Library and they are doing some exciting things over there. Most interesting is how they have made ArcIMS available to students. This is a great idea that I am hoping to duplicate here.

Hispanic Voter Population Projections in Texas to 2040

The very first spatial reserves project that I created here at UTA was an ArcIMS page entitled, "Hispanic Voter Population Projections in Texas to 2040". It is still being used each semester by 3 to 4 undergraduate political science classes. I consider it my Old Faithful.

If spatial reserves is a new catch-phrase for you, think of it as fast food GIS. We created an HTML template in ArcIMS, which is mostly a mashup of existing templates provided by ESRI and various free scripts available on the Arcscripts site. It was a bit of a hurdle to create the template, but once created, it is not much more than a few lines of edits to the ArcIMS parameters JavaScript file to create another instance of the template. For the students/users, it is theneasy as pie. They interact with the spatial data through the web.

Well, I am bringing this up now because the professor and I just submitted a proposal to publish a paper on our collaboration and how the concept of spatial reserves has helped his students to explore spatial datasets without having to learn to use GIS software.

For this particular project, I used Hispanic population projections from the Texas State Data Center and then the professor and I calculated the estimated portion of these projections that were eligible to vote (citizen above 18 years of age). I joined the results to a Texas county shapefile and plugged it into our template. Now students can analyze the effect of Hispanic voters on Texas politics in the ease of their comfy dorm-room chairs. It has been very popular and has even drawn some social science students to use ESRI software when they probably would not have even been exposed to GIS at all.

This is very similar to a paper I published last year, entitled "Faculty and their Institutional Librarians: Developing Labor Capital by Using GIS to Teach Social Science", page 21.

Thursday, September 29, 2005

Open Source & Freeware GIS

Saga GIS 2.0 was recently released (via comp.infosystems.gis) and this got me thinking about my favorite open source and freeware GIS products out there.

Last year, I held a workshop on Open Source/Freeware GIS options and Saga GIS was definitely one of the great one sthat I pointed out. The documents and data from that workshop can be found here (remember, though, that it is bound to be outdated by now and I have never had a chance yet to update it).

Here are my favorites:

This is by no means anywhere near a comprehensive list. These applications are just the ones that I use and recommend to others.

  • Christine GIS --
    For basic vector viewing and merging tables with shapes, this is my favorite by far. Very easy to use and even has a scripting language.
  • Forestry GIS (fGIS) --
    Also very good for vector viewing and lightweight vector file editing capabilities.
  • SAGA GIS – System for Automated Geo-scientific Analysis --
    This is without a doubt my favorite application for raster creation and analysis. Completely open source.
  • The Carbon Project --
    For those of us programming in the .NET environment, The Carbon Project is an "Open-Geospatial .NET development toolkit."
  • Diva-GIS --
    "A free geographic information system for the analysis of biodiversity data."
  • Quantum GIS --
    A suprisingly powerful all-around GIS application available for a variety of OS's. Recently mentioned on Spatially Adjusted.
  • dlgv32 Pro --
    I have not had as much experience with this one but I have heard great things and so I want to include it here.
  • ajmGeocode PE --
    I have yet to find a free batch geocoder. This is the best I have found to date. Sure it only will geocode one address at a time, but it compiles the results in a table that you can export.
  • GeoDa - Spatial Data Analysis Software --
    I cannot say enough good things about GeoDa. In fact, I have written about it here and here. This is an incredibly user-friendly geostatistical package that comes with far better documentation than most expensive alternatives. I often turn to this application as opposed to ESRI software.
  • Google Earth & NASA Worlwind --
    C'mon now, 3D interactive viewers like these are so fantastically wonderful that they are changing the face of GIS.
  • Scan Magic --
    The best free remote sensing software that I have used.
  • Sourcepole: GIS - Knoppix --
    Boot-from-CD Knoppix Linux, complete with a complete load of open source GIS applications. These are ready to run and will make even the most die-hard Windows user thinnk twice about their faith.
  • WinTopo: Raster to Vector --
    The best free application for heads-up digitizing and includes powerful automatic digitizing algorithms.

Migrate Blog From Bloglines & Repost First Post

I am migrating my blog from Bloglines ( to Blogspot ( I can not find an easy way to import the XML from Bloglines, so this blog will just continue here.

Why am I migrating? Comments. Even though I might not have a large audience, I want to at least gve anyone the capability to leave a comment. Bloglines does not allow comments.

The one posting that I will duplicate here is my first post, posted on: Thu, Jun 23 2005 10:37 AM.

First Post

By mapz

OK, this is my first real post.

About me:
My name is Joshua Been and I work as the GIS Librarian at the University of Texas at Arlington. GIS Services in the UTA Libraries are within the Information Literacy program area and I supervise 1 half-time GRA and 1 part-time work study student. There are many aspects to our responsibilities. We provide technical support primarily for ESRI ArcINFO and ERDAS Imagine. We have an annual budget to collect proprietary spatial data products. We are developing a metadata catalog using .NET. (This is almost complete and can be previewed.) We provide access to interactive browser-accessible maps using ArcIMS for courses that can benefit from spatial data and analysis, but do not have the necessary GIS skills. This project is called Spatial Reserves and a paper presented at the 2004 ESRI Education Users Conference can be viewed here. This summer (2005) we are installing Oracle 10g and ArcSDE on our dedicated GIS server as another means to provide access to locally housed data and metadata.

About this blog:
Well, I want a venue to discuss my ideas concerning GIS and librarianship. I want to post cool job opportunities that I find. I also want to dicsuss problems and solutions that I encounter working with the students and faculty here at UTA. I have open office hours for 15 hours every week where students and faculty can walk in with no appointment to receive assistance with GIS, data acquisition, or analysis. Often times, though less often during the summer, there is a line of people waiting for assistance.

With that said, I will stop writing right now.