Tuesday, May 12, 2015

Navigation with GPS

Introduction:


The purpose of this exercise was to set up a navigation course for future students using points plotted on a GPS. Each group was required to map five points, then navigate to them using a Trimble GPS unit to mark them. At each point, flags were installed, marking them for use by future groups. An important aspect of this exercise was setting up a proper map for navigation on the GPS. The same navigation map that was used in the previous navigation exercises was imported onto the GPS.  For more information on the navigation map's creation refer to this post.

This is an image of the map used for navigation. This was also used on the Trimble GPS unit.
The Trimble Juno GPS device used for navigation and point storing. 


Methods: 


Upon arriving at the priory, members from each group convened to plan areas to cover with each course. My group's course was set for the Northwestern corner of the Priory. The GPS, along with the navigation map and compass were used to navigate to this area. Once there, points were selected based on their relative locations to one another- we didn't want to make it too easy or too difficult. Their locations were also determined based on accessibility with respect to elevation change, vegetation and such factors. Trees were used as points, so they were flagged with fluorescent surveying tape and labelled. GPS points were also taken. However, our group experienced a temporary issue with this. Before going out into the field, the GPS unit was set up without a feature class to be edited. This means that the map that the Trimble unit had loaded didn't allow for adding any features. Because of this,  a new quick project had to be created, and points taken on that. This made the GPS unit useless for navigation purposes.

After collecting the field data and returning to campus, the five points had to be checked back in, and mapped. The results are shown below.


Results:


One of the points in the navigation course

One of the points in the navigation course
One of the points in the navigation course

A basic map of the locations of the points marked in the UWEC Priory

Discussion:


As mentioned above, the inability to edit any feature classes in the Trimble GPS map rendered the GPS useless for navigation. We were then forced to rely on map and compass navigation, as was done in previous exercises. This is just another lesson about how technology can fail, so it is important to have the background knowledge to be able to subside without it. The rest of the process went smoothly, and favorable weather conditions made the exercise very enjoyable. 


Conclusion:


Navigation methods today have shifted more and more towards GPS, so being able to properly set them up, use them to navigate, and collect data on them is a very important skill. We learned the lesson that overlooking just one little element of the data check-out process can render the GPS more or less unusable. However, building upon previous exercises, we had the skills to be able to navigate through our assigned section of the Priory and set up our course and return to our beginning point without any major issues. 

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