Wednesday, November 5, 2014

Exercise 6 - Data Normalization, Geocoding, & Error Assessment

Introduction - In this exercise we used data from a excel spreadsheet and normalize the data. We then learned how to geocode the data and assess our errors based on our classmates results. The data we were using was addresses of sand mines in Wisconsin for our semester long project on frac sand mining in Wisconsin.

Methods - We first tried to geocode the data using ERSI ArcGIS Online's World Geocode Service. However, since our data wasn't normalized we weren't able geocode any of the addresses. So, we normalized the data by finding the addresses, zip codes, and town for each mine. Many of the sand mines had PLSS addresses so we had to use a school server to find street addresses for those mines that didn't have one. Once we had the data normalized we were able to successfully geocode the address using the World Geocode Service.

Results - Once we geocoded the sand mine locations we were able to map them out in ArcGIS.

The original data before normalization

The data after normalization, ready for geocoding
Map of the geocoded sand mine locations in Wisconsin
Each of us in the class was given about 20 mines to geocode and at the end of the exercise we compared our geocoded mines with those of classmate's who had the same mines. Below is a table of the mines that I geocoded, their name and the distance from my classmate's geocoded location of the same mine.

Mine ID


Facility Name

Distance of my geocoded location
from closest classmate's
(rounded to the nearest meter)
109
MIDWEST FRAC AND SANDS
0
111
SIOUX CREEK SILICA
0
125
RIVER VALLEY SANDS
14313
136
MUSKIE PROPPANTS
0
138
PREFERRED SANDS
0
151
FG MINERALS (WISCONSIN INDUSTRIAL SAND)
0
152
FG MINERALS LLC
0
163
ATLAS RESIN PROPPANTS, LLC
11383
165
BADGER MINING CORP-TAYLOR PLANT
10603
178
TOWN OF BROCKWAY MINE
0
179
WESTAR PROPPANTS LLC
246
190
BLACK CREEK LIMESTONE CO
3044
192
DIAMOND BLUFF INDUSTRIAL SAND
239
205
ARCARDIA SAND CO
0
206
D95 NORTH SITE - SPARTAN SAND, LLC
1614
218
PATZNER SAND PIT
0
219
PREFERRED SANDS OF WISCONSIN, LLC
2920
232
VERNON BUE SAND MINE
4850
233
FML SAND - READFIELD
3187
245
NORTHERN FRAC SAND LLC
604
246
CHOPPER FARMS
128

Discussion - My data and my classmates' data have low positional accuracy due the uncertainty of certain address were we had rely on PLSS interpretation in order to assign an address to some of the sand mines. There is a inherent error in the data automation and compilation. In some cases there is no knowing which location is correct, however in other cases which show large differences in the data you can see that one or the other point is more accurate based on the PLSS address.

Conclusion - It isn't easy to normalize and geocode addresses especially with a PLSS address instead of a street address.

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