GIS Doctor Mailbag

This blog has been up and running for a while now and I have gotten a number of email questions, responses to blog posts, and search engine keyword questions.  Let’s answer a few of them!

How do geographers collect spatial data?

  • By many means.  There are the arm chair geographers (like me!) who collect, develop and analyze spatial data from a variety of published data sources and there are those geographers who go out into the field.  These rugged souls create and administer surveys, collect data in the field in all conditions, and develop scientific studies to derive their own data.  Depending on the nature of the study a geographer may use a mix of data collection methodologies.

How do I use more memory with ArcGIS 10?

  • I hear this question more and more, especially as more users have 64 bit machines and automatically assume that everything will be faster.  ArcGIS 10 will use all the memory available in a 32 bit environment, which is 4 gigabytes. However, not all the tools and processes in ArcGIS will use all the memory.  To work around this problem users can chunk their analysis to try to speed things up, or they can review their analysis and try to develop a set of processes that make the analysis smaller, therefore faster.  In the past I have split up large input data sets (20 million plus points) and used python and ArcGIS tools to have the analysis run effectively.

How much ArcGIS Server 10?

  • Not cheap.  If you want free check out MapServer.

How can I get Bing Maps in my GIS?

  • If you are not behind a firewall a user can click on the Add Data button in ArcGIS and select Add Base Map.  The Bing data should then be a base map option. Since my instance of ArcMap is behind a firewall I cannot add the Bing Service. This is a bummer, since I am a big fan of Bing Maps.

How can I add Google Maps into ArcMap?

  • There isn’t a quick tool to load Google Maps into ArcMap.  However, there are a few applications out there that allow a user to port in the imagery from Google into ArcMap.  One well known tool is provided by Arc2Earth.  Now, if the user is running ArcServer Esri provides a number of tools to publish data in the Google Maps interface.

How do I kill a geoprocess ArcGIS 10?

How do I speed up ArcGIS 10 on 64 bit machine?

  • Wait until Esri releases a 64 bit version of ArcGIS, or start using GIS software that is native 64 bit.

Is it possible to use embed a WMS data source into a Google Maps mash-up?  

  • Why, yes it is.  Check some examples here

Is ArcGIS difficult to learn?

  • I’ve been in the field of GIS for close to 10 years and I’m learning something new about ArcGIS everyday. GIS is complicated and the theory behind it is deep.  Many want GIS software to be simple, but users need to understand the details to properly frame an analysis and understand the results.  If GIS were very easy I believe you would get many people, more so than now, making poor decision from poor analysis.

Why did Esri skip version numbers?

  • They did?

What is wrong with ArcGIS 10?

  • Unfortunately, plenty.  Check out the bug fixes for SP1 and SP2.

Why do ArcGIS tools take so long?

  • Another question I hear all the time,  “why is process XYZ so slow?”.  The answer is never as direct as the person asking the question wants it to be.  There are a number of reasons why a particular process or processes may be slow.  To try to understand the issue I always work through a series of questions.  First, what are the specs of the machine running the process?  What other processes are running on the machine?  What are the dimensions of the data being processed?  Are the data sets in the analysis in the same projection? How large is the data, both spatially and in memory?  How intensive is the process itself?  How detailed is the data being processed?  The point is that there isn’t always a smoking gun to solve all processing questions.  Sometimes the process will be slow.

OK, that is it for now.  If you have any additional questions drop me a line!  Until next time.