Lab 12: Development of a Field Navigation Map

Introduction

            Having already learned how to use GPS units for navigation exercises as outlined by the blog posts below, the purpose of this lab was to expand our GPS skill set to include database design and creation for deployment in the field to a handheld GPS unit. Outlined by this blog post will be the methods involved in how to prepare for specific data collection in the field in regard to the database structure deployed to the GPS unit prior to the gathering data. Specifically, information for restoring the recreational features at the Priory owned by UW- Eau Claire would be gathered.

Methods/ Discussion

            The first step in creating the database that would be used to map these recreational features was to brainstorm a list of possible topics that could be easily mapped at the Priory. The list compiled included: trails, benches, erosion points, notable view points, large/ notable trees, woodpecker holes, human objects (garbage, dumps, fence, deer stands, trail markers, etc.), animal tracks, and bird houses. Next delegation of these topics to the three person teams the class was divided up into took place so teams were only responsible to map a specific feature at the Priory.

            My team consisting of Tonya O. and Chuck P. were assigned the trails of the Priory and decided to map all trails to include several attributes. The attributes to be mapped were trail surface, trail condition, and trail use. To aide in data collection and to standardize all recorded attributes, domains were created. The purpose of domains is to finalize what specific attributes can be recorded because a list of specific options (domains) will display once an attribute is selected on the GPS unit. For all of our domains, we used the text setting to record data type. In addition to selecting text as the data type, other domain coded values include float, short and long integer, raster and other types to allow for specific data types to be defined. Some benefits of using well defined domains are they expedite data collection because it allows the user to pick the domain from a drop down list instead having to type them in each time, and it prevents spelling errors that would affect our ability to manipulate and sort the data when post processing.

Figure 1: Trimble Juno GPS unit used for data collection at the Priory

Figure 2: Data structure within Trails trails feature class for deployment to the Trimble  Juno GPS unit for data collection at the Priory.

            After the domains were set for each attribute in the trails feature class, the geodatabase it was contained in was brought into a session of ArcMap to prepare it for deployment by changing the symology of the features to pertain to the data being gathered. In addition to changing the symbology of the feature class to line, a raster clipped down to just show the Priory would be included to help facilitate data collection by providing a basemap to reference. Next, using the ArcPad Data Manager Extension within ArcMap, the geodatabase layers we created were deployed using the “Checkout Wizard” function. Once the map was turned into a file type (.apm) that the Trimble GPS could recognize, simply copying and then pasting this folder onto the SD card on the GPS was all that was necessary to finish deploying the database to the unit. Once deployed, simply opening the file within ArcPad on the GPS was all that was necessary to begin data collection. Instead of having the GPS unit automatically and continuously drop vertex points as we walked along the trail, we decided to manually plot the points periodically along the trail to follow its path in addition to assigning the coded text domain values. Following collection of the attributes for the trails feature class, we then uploaded the line feature collected back into a session of ArcMap to be displayed.

Figure 3: Trail condition map of the Priory 

Figure 4: Trail surface map of the Priory

Figure 5: Trail use map of the Priory

Conclusion

            Although our class was unable to compile a complete map of all of the proposed topics at the Priory, we were able to gain many valuable skills regarding database creation for deployment in the field. In addition to those skills, we also had to trouble shoot problems as they arose due to the fact that many of us had never created a database like this from the ground up before which is in my mind, a very effective method to teach this. In conclusion, I found this lab extremely valuable because it allowed us to come up with the domain types on our own to show us how important it is to put thought into database creation prior to deployment in the field so you know specifically what it is that is being collected.