GPS Navigation

Introduction

This exercise was very similar to the traditional navigation exercise and was at the same study area, but this time we were using the more modern navigation strategy of a GPS and completing all 15 points of the full course at the priory. It also required some more work to be done on the maps we produced for navigation to add the points and decide upon a route for our group.There was also the added bonus of the whole class being armed with paintball guns as we were all completing the course!

Methods

First of all we had to go back and edit our maps in ArcMap during class time. Now we had access to the shapefile containing the points of the course as well as the three starting points, so we had to add them and ensure they were a suitable colour to stand out against the background map. Then on this map it was important that we included the polygons for the no-shooting zones, as there was a children's centre in the vicinity and one are was also near a main road, so we did not want to be shooting our paint ball guns in those areas.

Then, as a group we examined the topography and used our knowledge of the five points we had previously found to decided upon a route that would be the easiest to navigate and the fastest to complete. This mainly ensured that if we were going down in relief we stayed down and if we were going up we stayed up, as much as we could. The points shape file's attribute table has the points numbered in the course order, so we had to change this so they were numbered in the order we would be navigating them. Also, the starting points were included int he numbering system, so we made sure they were not included in our numbering system. We also made sure that these numbers were visible so we could see them on the GPS unit screen.

We then attached the GPS unit to the computer with a USB cable, and cut ad pasted a copy of the map file in to the device's folder on the computer. We then turned the unit on and made sure that we could open our map document and that everything that was meant to be displayed was. Also, that there was not to much information on the unit and made the screen to busy so we would not be able to read the map properly. We also had to ensure that we remembered the number of our unit, so we could get the same one when we out in the field so that it had our map file on it.

Whilst out in the field each group had one person with the GPS device navigating the group, as the others were on the lookout for the markers and other groups potentially firing paint balls. The tracklog was switched on, to follow our route and log each time we we had reached a point. We then followed the course displayed , but went of course at times when we had to hide from other groups, so then had to find our way back to the route we were meant to be following.

Discussion

It was quite difficult to decide what to include on the map so as not to overwhelm the GPS unit. We did have to slightly decrease the size of the numbers marking the points,k as they were preventing us from seeing the rest of the map. When using the unit in the field, it was very sort of trial and error, we had to just walk in a direction and see if our track log was following the route or not, and the adjust accordingly until we were following the line on the screen.

There really wasn't much room for us to zoom in or out of the map as it would take a very long time to slowly load, and we were meant to be going as quickly as possible, So, we had already decided that we would print out a copy of our map anyway which came in very handy when the screen would be loading or froze. Our group also did not realise that we had to add a point to the map every time we reached a marker we assumed that it would be shown in the fact that our route had gone past/through the point.

At one point the unit quit out of the map and then took along time to open up again, so we had to seek shelter in a small valley and try and use the paper map without a compass. Then once it had opened again it had lost our tracklog, so according to what our map would show you we did not do the course.

I think that we would have been able to navigate the course a lot quicker if we were using the traditional methods as once we had a rhythm and pattern it worked efficiently. We can also see the whole map and are we need to on a paper map without having to wait to zoom in and out. But I can see how much easier it is to just carry one device, especially when you have paint guns!

Study Area

The study area, as should be apparent, is the same as was used in the previous traditional navigation exercise, except we were physically covering more of the course rather than just one section.

Conclusion

When planning an efficient route it is important to make sure you are not climbing up and down hills constantly, and you do not go back on yourself if possible. When putting a map on to a GPS device you must consider what is necessary to see, so you use as little memory space as possible. As people should do with their Sat-Navs in their cars, you should follow along with map also, so you are not led blindly astray, and you can not always rely on technology to work efficiently and properly. As for the paint balling, I don't really think it was my cup of tea!