OK. I’m not a GeoHipster. I’m a GIS Worker. This is what I do.


But worry not, GIS worker: Spatial might no longer be special, but projections, datums, and legacy file formats will continue to be very, very special.
      – Brian Timoney, MapBrief

Okay… GIS is not sexy like your iPhone locator app.  But it will always be special.  In the same way that your plumbing and electrical and HVAC systems are special.  Next time they stop working, ask yourself just how special they are.  Next time your iPhone map is missing Main Street, ask yourself how special GIS is.

Consumer and business geo apps and services keep evolving – cutting edge today and obsolete tomorrow.  BigData today – legacy file format tomorrow.  But projections, datums, and georeferencing will always be there to provide ground truth. 

Esri and the ArcGIS platform have been around for 30 years, defining and documenting GIS work.  So when we needed to understand what GIS workers are doing across a variety of industries, we looked at the list of tools in ArcGIS Toolbox as a compendium of GIS workflow and process skills.  

We needed the ArcToolbox list itself as a data set — not a PDF poster or searchable web site.  I asked Esri for an ArcToolbox list as Excel table or other word processing format, but they could not provide.  So my friend at Esri, Nick Toscano, and I compiled the table ourselves.   That’s almost 900 “GIS tools” in an Excel data table.  Easy to sort, filter, annotate, categorize in ways that meet our needs.  

Here it is.

Some of the tools are pretty arcane.  But most are plain markers for the nuts-and-bolts work of GIS professionals in towns, cities, and counties who have to deal with projections, datums, and legacy file formats every day.  Not the next wave or next-big-thing.  Just the actual data and task at hand.

How will we use this?

  • Survey and assess the experience of our GIS workers.
  • Plan GIS skills training and investment.
  • Design new workflows to make common tasks more efficient.
  • As a quicker reference for building geoprocessing services. 



Am I projecting or transforming that coordinate system? Or both?

We received a shipment of data from Esri for Philadelphia business locations.  We needed it transformed from geographic coordinate system (lat/long) to Penna State Plane South (3702) coordinate system (in feet).  Esri told us we have to do that ourselves.
Projections, coordinate systems, and transformations are always a little confusing for those of us who don’t mess with them a lot.  Esri’s tool labeling doesn’t help any.
We had a team huddle and decided we were not projecting a coordinate system — we were transforming from one coordinate system to another.  I looked in ArcToolbox under  Data Management > Projections & Transformations.  There is no Transform tool.  So I tried the only tool in there for Features:  Project.
I opened the Project tool and ignored the options first time around.  Got an error for not choosing the option:
Read the Help.  The option is required if you are changing coordinate systems.  Which is what we came here for in the first place.
How to choose?


Not sure.  I saw no hints in the input or output coordinate system descriptions.  So I used the first option on the list shown .  Looks like to worked fine.  This tells me where in State Plane:

Questions:

1.  Were we transforming or projecting?  Or both?  

2.  Is “re-projecting” a necessary step in transforming a data set’s coordinate system from one to another?

3.  How do we decide which Geographic Transformation to apply?

I appreciate your comments.


Projection weirdness in ArcGIS and at AGO

I’ve been working with Philadelphia Public Safety to look at our ArcGIS Server map services in ArcGIS Online maps.  Our points were plotting over central Africa, not Philadelphia.

Obviously, we suspected that part of the problem must be the Penna State Plane coordinate system that we use.  One weird clue was this:  When we added the PPS basemap (Penna State Plane) as basemap to the AGO app, the point layers plotted ok.  But if we used the Esri basemaps that are default on AGO, the points float over Africa.

We compared the few data layers that displayed ok, against those that didn’t.  We found that the bad map layers didn’t have the right coordinate system listed in the Data Frame Properties in ArcMap.   We tried different scenarios to fix this.  The point layer was created as an XY Event Layer.  If we added this first to the ArcMap Data Frame, the coord system would not register correctly to the Frame.  We had to first add the PPS basemap (Penna State Plane) to the map, then create the point layer, then remove the basemap before publishing the service to ArcGIS Server.

We don’t understand why.  Do you?  Leave a comment.