PASDA GIS Data Reminder

As the Oil and Gas boom has hit Pennsylvania, GIS data is a prime commodity in obtaining permits and generating needed concept plans. A major source is the Pennsylvania Spatial Data Access (PASDA) clearinghouse. And I quote:

Pennsylvania Spatial Data Access (PASDA) is the official public access geospatial information clearinghouse for the Commonwealth of Pennsylvania and has served for fifteen years as Pennsylvania’s node on the National Spatial Data Infrastructure, Geospatial One-Stop, and the National Biological Information Infrastructure.
PASDA was developed by the Pennsylvania State University as a service to the citizens, governments, and businesses of the Commonwealth. PASDA is a cooperative project of the Governor’s Office of Administration, Office for Information Technology, Geospatial Technologies Office and the Penn State Institutes of Energy and the Environment of the Pennsylvania State University. Funding and support is provided by the Pennsylvania Office for Information Technology,Geospatial Technologies Office. In addition, PASDA also receives substantial support from the Pennsylvania State University.

So there are tons of great data types to choose from, depending on your needs. But there is one question I often get asked and rarely remember the answer. For some reason, some data is formatted to be in the coordinate zone Antarctic98.LL, which refers to the Lat Long grid for the Australian Antarctic 1998 datum. Of course, this is not correct. So the first place to research is the metadata.

Within the metadata (and Map 3D has a metadata viewer), there is a section entitled, “Spatial Reference Information.”


But as you can see, there is the reference to Australian Antarctic Datum 1998. Hhmm… where to look next. Oddly, in the “Identification Information” section, there is spatial information giving you the bounding coordinate values of the geographic data.


Based on these coordinate values, we can gather that we are definitely in a Lat Long system, but which one? We have so many to choose from?


If you scroll down that list, you will see a set of codes that begin with LL.  It’s in this area we will find our target. But sadly, It is a bit of trial and error.  I already had a shape file in my drawing that was located correctly. I then had to override the offending coordinate system for each try.


And the winner is…  LL83. Now your data should fall in the correct place!

UPDATE 10-29-2016: I recently found other data sources (National Wetland Inventory for one) that referenced NAD83 Albers projections in meters. Except the 83 Albers projection is only in feet. So I tried the NAD27 Albers projection and that correctly placed the dataset.


About Kevin
Hi… I am a husband, father, brother and neighbor. I am employed as a Civil Engineer and have enjoyed playing the drums for the last 30+ years.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: