GPS Data Collection

Introduction: This weeks activity was to go back to the Priory and collect data of the various features of the Priory. We first decided on the data we wanted to collect, then created the necessary data within ArcMap. We then used a Trimble Juno to collect the data.



Trimble Juno 3D.

Methodology: The first thing our group needed to do was to decide on the data that we wanted to collect. The Priory is a very wooded area with some dramatic topological changes. Some of initial idea was erosion points, significant trees, bench locations, trail locations, etc. We decided on trail locations. We were a little unsure what to expect, because when we were at the Priory in the winter, there was no real obvious trails. The snow was about 2 feet deep, so the trails blended in well with the surrounding landscape. The different Attributes we decided to record were Trail Use, Condition and Surface.

 

After deciding on our purpose we needed to create a geodatabase to store our GPS data. We were required to create a folder titled ‘CheckInOut_Username’, and then within that folder we needed to create a geodatabase named ‘Priory_username’. My username is petersct, so in place of username was petersct. We then had to create a feature class within the geodatabase based on the type of data we were collecting. We were collecting data on trails so we created a line feature class, in contrast to point or polygon. We were also required to set the projection to NAD_1983_HARN_Wisconsin_TM meters.

Now that we had the feature class created we needed to set the domains. The domains is the area where you set your data categories within the feature class. For example, I collected the data for Surface type. By different surface types were Pavement, Dirt and Gravel. By setting up your domains you are not required to type in the whole word while you are out in the field eliminating a lot of errors. We also created another domain for ‘Other’, which gave us an option if we ran into some unforeseen type of surface like Yellow Bricked.

Here is my collection of trail data.

All of the Trails put together from the group.

Conclusion: It was nice to go out to the Priory with no snow. It was also nice to actually be able to get out there and see everything that it has to offer. There were plenty of trails for us to find. I'm quite certain we were not able to get to all of the trails. I think our group got a good start on the trails for future reference. I thought this was a good exercise and gave me some experience with the Trimble unit.

High Altitude Balloon Launch

 

Introduction: A High Altitude Balloon Launch aka: HABL, is where you send the same weather balloon, as used in the previous Balloon mapping, but this time sending it into altitudes above 60,000 feet. There are a few different obstacles to tackle when sending something this high into the altitude.

Recap: Two things happen as you travel up through the atmosphere. The temperature drops dramatically and the air pressure lowers.
First the significance of the Temperature. Due to the extreme cold as you climb in altitude the camera must be secured so it does not freeze. Also as the air pressure drops the balloon will expand because the pressure within the balloon is greater than the outside pressure. Eventually causing the balloon to burst and fall back to earth.

Altitude above Sea Level	Temp. (F)	Pressure	Air Density
5000	76.84	17.554	27.45
0	59	14.696	23.77
5000	41.17	12.228	20.48
10000	23.36	10.108	17.56
15000	5.55	8.297	14.96
20000	-12.26	6.759	12.67
25000	-30.05	5.461	10.66
30000	-47.83	4.373	8.91
35000	-65.61	3.468	7.38
40000	-69.7	2.73	5.87
45000	-69.7	2.149	4.62
50000	-69.7	1.692	3.64
60000	-69.7	1.049	2.26
70000	-67.42	0.651	1.39
80000	-61.98	0.406	0.86
90000	-56.54	0.255	0.56
100000	-51.1	0.162	0.33
150000	19.4	0.02	0.037
200000	-19.78	0.003	0.0053
250000	-88.77	0	0.00065

Methodology: We used a small styrofoam cooler to house the camera. This housing served a couple purposes, it would keep the camera warm and also help in protection of the camera once it fell back to earth. The camera was then secured into the cooler with a couple of heat pads to help keep the camera warm. We used the same type of heat pads that you would use for hunting or some outdoor activity in the winter.

Here is the class taking out the balloon for the launch.

This balloon was bigger than the one we used for the other aerial photography. The balloon was going further up in altitude and needed to be allowed some space for expansion. The camera rig was fastened onto the balloon as well as the GPS tracking device(so we could track the camera and retrieve) as well as a parachute for the descent. The above photo gives a good idea how big the balloon was, nearly 8' in diameter.
It was a fairly good day for the launch. The wind was out of the west so the balloon immediatly took off to the east.

One of the first still photos made. You are looking at UWEC campus.

Here is a great still photo made by the camera at some higher altitudes.

 

 

This photo shows that the balloon is probably reaching it's maximum altitude. Seems you are starting to see space in the upper left hand corner.

Finally the camera falls back to earth and we are lucky enough to get a signal from our GPS device and able to go and retreive it.

There it is stuck in the tree.

And, Dr. Hupy doing some climbing.

Here is the whole contraption. The orange cooler holding the camers, the tannish balloon and the blue parachute. 

 

As seen in the map above, the balloon took a ESE(East Southeast) path from Eau Claire.The balloon eventually travelled nearly 80 miles!

 

http://desi.uwec.edu/Geography/Hupyjp/Weather_Balloon_1024.asx Here is a video of the launch from earth.

 

Conclusion: I think this exercise was one of the coolest ones that we did. I think this would be a great way to teach any age group of a wide variety of subjects. You could teach geography, meteorolgy, atmosphere, etc.



Aerial Photo Mosiacing

Introduction: With all of the data from our Balloon mapping, the photos needed to be put into a mosiac. Instead of using a free program off of the internet, I used ArcGIS this time around. ArcGIS offers more flexibility in photo manipulation as well as allowing you to georeference with control points.


Methodology: While some students flew the balloon over campus some others took out a GPS unit to record some control points. The control points serve as a reference point on the land scape that allows you to georeference your photos. The control points are recorded at points that can be seen from satellite imagery. The idea is if the control point is suppose to be at a light post, you can georeference your photo to that light post. Besides lining up sidewalks, roads and building, the control points give you one more tool to align photos up to an existing background.

Control points

With such a large area to mosiac, the class also split the University up into smaller areas to be mosaiced by groups of three.

Area to be mosiaced

With my little experience in mosiacing, I gave my best shot at getting the photos lined up.

Here is the same map with my first picture mosaic.

And my second picture.

Discussion: The most difficult part of this exercise was to work with the different angles that the camera took. Even on the calm day that we had for the second balloon launch, there are still angles that you have to deal with especially with buildings. Also with over 5000 photos to choose from, it can be rather dull looking through all of the photos and trying to find one that doesn't have too dramatic angles.

Conclusion: Once again this was an interesting exercise. This would be a good way to get some detailed photos of a piece of property for planning, etc. I enjoyed this exercise and it gave me some more time to work with ArcMAP. It was also interesting to see how much has changed at the University with all of the construction.