Author Archive

State-based Spatial References – Projection Files

Sunday, November 11th, 2012

This past week, I received an AutoCAD drawing that did not have a customary state plane coordinate system associated with it. So, I spent some time plugging in different projection files until I figured out what the projection was of the drawing.

After going through that hassle, I decided to create a set of webpages to simplify that task for me, for the next time I have to go through that effort. I am making those webpages available on my website for others to use.

The link to that is:

Just click on the state in the map, that you are looking for projection data for. Enjoy!

Florida Sinkholes Mapping

Saturday, May 5th, 2012

Florida Sinkholes Mapping, Using ArcGIS 9.3

The news of the Karst sinkhole, that just occurred behind the home at 4926 Indian Deer Rd, in Windermere, Florida, got me thinking about the availability of sinkhole data in the state of Florida. Although it about one year out-of-date, I did manage to find some GIS data on Florida sinkholes. I created a basic static map, which can be viewed at

I am creating a time-lapse GIS map of the sinkholes of Florida, as well. I am using the temproal tools of ArcGIS 9.3 for this animation, which should be online within the day.

An Earthquake Series Animation, Using ArcGIS 9.3

Saturday, April 14th, 2012

After seeing a video that went viral, by StoryMonoroch, on YouTube,, I decided to figure out how to accomplish something similar, using ArcGIS 9.3.

My first step was to get some earthquake data. I chose to use earthquake data from the US Geological Survey (USGS), that covered the previous 7 days, for earthquakes of 2.5 magnitude or higher. The link to this data is

The next step was to convert the date and time field into a format that ArcGIS animation tools would work with. I decided on using the format, YYYYMMDDHHMMSS, as it would be relatively easy to create the formulas necessary to convert the USGS data into.

The webpage with this is located at:

ArcPad 7.1.1

Friday, June 20th, 2008

This past weekend, I downloaded and installed ESRI ArcPad 7.1.1 on my Dell Axim X50, to see how it worked before installing it on the Trimble Recon. I think that the first mistake that I made in the install was to uninstall all the ESRI and Trimble products, and NOT perform a reset. After installing ArcPad 7.1.1, then Trimble GPSCorrect 2.30, I attempted to run ArcPad. After the program opened, none of the pop-down menues would pop down; I only got the top icon. Time was running out for some other errands that I had to do Sunday, so I just uninstalled what I thought was everything ESRI and Trimble and headed on my way.

At some point early this week, I went onto the Axim and automatically started ArcPad, forgetting that I had “uninstalled” it. Lo and behold, not only had I not uninstalled it, but it worked correctly! So, I went ahead and installed GPSCorrect 2.30 and things still were working just as expected.

Yesterday, while at a site, I had been running ArcPad on the Axim with a low-budget Bluetooth GPS unit (GlobalSat BT-338) that I use to record tracks of traveling. Then, I went to use it, but the screen had dimmed, so I did my usual tap the center of the screen and ArcPad just disappeared! I ran the app again and got to my last save just fine, it had not saved the very last polyline, but up to that point had saved correctly.

Blank Edges in Hillshades

Sunday, March 2nd, 2008

When mosaicking DEMs, sometimes gaps of “nodata” result. Here is a technique that I employed to address this.

A Starting Point

Friday, February 29th, 2008

This is a starting point for what I hope to be a discussion forum for my experiences in GIS.