I remember making this feature class...I wonder why?
Have you ever wondered where a feature class came from as you've browsed over one of your geodatabases in ArcCatalog? I think most of us have, and probably more often than we'd like to admit. In the example shown here to the left, I made these datasets a few weeks ago, and I have no idea what "GN" means, and if or how I selected, simplified, or dissolved the data.
There are a couple of things we can do to avoid that puzzled feeling: standardize your feature class naming convention; standardize your geoprocessing. With the naming convention, I started doing the right thing here, but failed to follow through and leave myself the necessary clues. The data in the image above was also the result of a complex workflow, so rather than start with that, let's cover the basics.
Use Standard Feature Class Names
My example here fell apart because I was using the framework for a standard naming convention, but my naming convention wasn't entirely standard. The framework that I was using creates feature class names based on who first published the data, and then what the data represents. So, NHD_Flowlines means I got the data from NHD (USGS National Hydrography Dataset), and the data represent stream flow lines.
Second, while my example started off with a good name, I had not developed a standard convention for any of the processes that I ended up doing to my NHD_FlowlinesPlus dataset to produce my cryptically named datasets. Before I explain what I should have done, I'll share the standard naming conventions I use:
- Scale: _24K, 100K, 250K, 1M, 2M: The first example means the data are either captured or generalized to be at a resolution appropriate for 1:24,000 scale maps. The 1M means 1:1,000,000. This is a relatively good convention; I say relatively, because the meaning is map product and data-production specific. The product in this case is an on-screen map, and I use different data production methods from that which I would use for a printed map.
- Mapping Purpose: _lab _sym, _master: This refers to how I use these data in a map. If it is for labeling only (_lab), for symbology only (_sym), or a dataset that I use to derive cartographic data, (_master). The context I have found most useful to use these abbreviations is ArcGIS Server, my goal there is to optimize the data to the greatest extent possible to improve drawing performance. I covered how to set that data up in a recent blog entry on tips for improving drawing performance.
- Vintage: _03, _07, Mar_08, Jun_06, etc.: This is just a two-digit year so I can tell when data are captured. For imagery, it's useful to add at least the month or even the capture date to the name as seasonality often carries significant meaning.
Read More: Mapping Center : I remember making this feature class...I wonder why?
No comments:
Post a Comment