ArcPad Data Collecting

Introduction
This week we will be going out to the Priory again to collect data using ArcPad. The purpose of this exercise was to introduce us to the use and functions of ArcPad. We had to create a geodatabase from scratch. This database needed to contain features that could be found at the Priory. These features in turn needed to have attributes and have domains.

Methods
The first thing that we did was decided on what we wanted to collect out in the field. My group decided we would map out fallen and dead trees. Both features would be point features. The fallen trees had the attributes of diameter, length, state of decomp, fungal presence,and azimuth. We would use the azimuth and length to generate a line feature showing which way the tree was actually laying. The dead trees had the attributes of diameter, presences of woodpecker, woodpecker use, fungal presence, height and vertical state(leaning or standing). We collected some trees from all over the Priory. Figure 1 shows the final map of our data collection.

Figure 1: Final map of our data collection.

Discussion
The trickiest part of this data collection was getting an accurate measurement of the length of fallen trees and the height of the dead standing trees. This was difficult because we were using a laser range finder to gather the length/height of the trees. This ranger finder works by sending out a laser out at an object and calculating the distance/azimuth of that object. Actually shooting the beam was not difficult. What made it difficult was that there were often branches or bushes in the way of the beam. It would hit these closer objects and not the real target father away, giving us a false reading. Also with the distance we needed to add about 1.7meters to the height attribute of the dead standing trees. This is because when I was shooting the height I was getting a false reading just by standing. I am 5'11" or 1.7m. We needed to add this to the height field because I was shooting the height 1.7m off the ground.

 Below are two maps showing the different attributes on dead standing trees. Figure 2 shows trees grouped by diameter. Figure 3 shows trees grouped by height.

Figure 2: This map shows dead standing trees sorted by diameter

Figure 3: This map shows dead standing trees grouped by height

Below is a map showing the fallen trees and a line feature showing in which direction these trees have actually fallen.

Figure 4: This map shows the fallen trees and the direction they lie

Results
This exercises taught us the importance of thinking and planning ahead about just what you want to collect out in the field. You need to decide what it is you want to collect, what type of feature it is and what types of attributes each of these features need.

HABL Launch

This week we launched the high altitude balloon launch (HABL). This rig is able to reach 100,000 ft above the Earth's surface. We had tested this rig several times during our first two launches with our aerial photography. Figure 1 shows us getting ready to launch our rig into space. Our rig had a video camera and a tracking beacon inside of it. The rig was packed with hand warmers and foam to keep the camera and beacon safe and warm. There was also a parachute attached so that the HABL could return to Earth safely. We did lose the beacon for almost an 1.5. But finally we were able to get a lock on it. The rig had landed in Marshfield, Wisconsin. This is about 78 miles east of Eau Claire. Joe and a couple of other students went out to retrieve the rig. Figure 2 shows the HABL had landed in a 50ft tree. To get it out of the tree, Joe had to climb up and get it.  Figure 3 shows our teacher Joe getting the rig out of the tree that it landed in. 

Figure1

Figure 2: The HABL up in a tree

Figure 3: Joe climbing up to get the HABL

Figure 4: The HABL is safe on the ground.

Below are some still shots from the footage the HABL took on its journey.

Balloon Mapping 2

Balloon Mapping 1

Introduction: 

 Earlier this year we did some preparation work in order to launch a weather balloon to obtain aerial photography of UW-Eau Claire campus. Thanks to this work done a head of time we were prepared to launch our rig attached to the balloon with no problem. It was decided not to use the soda bottle rigs instead we would use the high altitude balloon launch (HABL) rig as a dry run for the real HABL launch later this semester.

Methods:

In order to have a successful launch the class split up into several different groups to complete these tasks. In order to get the rig into the air we had to get the camera rig ready, get the helium tank down to the shed, get the balloon filled, and measure out 400 ft of rope so we would know how far we know the balloon was up in the air. We also had a person whose sole job was to take pictures and anther to take video.

Below Figure 1 shows the helium the tank down to shed so we could fill the balloon up. Down at the shed the used some plastic tubing to fill the balloon up with helium. They used zip ties to make sure seal the balloon close. Figure 2 shows the filling of the balloon. Figure 3 shows that the balloon is almost filled. Someone had to hold on to the balloon while it was being filled. Figure 4 shows the zip ties being used to seal the balloon.

Figure1: The transportation of the helium tank

Figure 2: Filling up the balloon

Figure 3: Balloon almost filled

Figure 4: Zip ties used to close of the balloon

With the balloon being filled, we needed to get the string measured out so we would know how high the balloon was in the air. To do this we unwound a real of string. At every 50ft interval we marked it with a permanent marker.

Figure 5: We used Red to mark 50ft and Black to mark 100ft

Figure 6: We used the tiles on the floor, which were one foot long, as a measuring unit to measure out the string

 Earlier this semester we had built two different rigs to hold our camera. However it was decided to use the HABL rig for this launch. By doing this Joe and the rest of the balloon rig engineers would get an idea on how it would react in the real world. Figure 7 shows the two rigs we built earlier this year.  Figure 8 shows the HABL rig that we used for this launch.

Figure 7

Figure 7

Figure 8: the HABL rig. We actually had two rigs built just in case

With all the jobs done we were ready to launch the balloon. We choose to launch the balloon in the center of the green area. UWEC had undergone a large face lift this past year and half. We lost our old Davis center and gained a new one. We are also in the process of building a new education building. With the imagery we would collect with the launch we could get a new aerial view of our new campus. Figure 9 shows us launching the balloon. Figure 10 shows us watching for the 400ft mark that we had mark on the string. 

Figure 9: The launch of the balloon rig

Figure 10: Counting out the feet

After we got the balloon up in the air we walked around the green for awhile. We then took the balloon down so we could switch out the cameras. The first one was a regular camera set on continuous mode. This time we would be using a flipcam that would take video instead of pictures. Figure 11 shows our the flipcam that we used.

Figure 10: The flipcam we used in the second rig

 This time we decided to take the balloon across the foot bridge over the river. We manged to get across the bridge with no problem. The real issue came when we began to reel in the line. The string snapped and the rig fell into the river. The video below shows the string snapping.

Luckily Joe was able to retrieve the rig from the river. The camera was fine and so was the tracking beacon we placed inside. Figure 11 shows Joe climbing back up to the sidewalk after getting the rig out of the water.

Figure 11: Joe climbed down to the waters edge and used a branch to snag the rig out of the water.

Georeferencing and Mosaic:

Now that we had our images we could georeference them. To georeference an imagine means we take a regular picture and establishes it's location on the Earth. I used ArcMap to georeference the images. I used a reference picture to help me georeference the images. This reference image is already georeferenced and is close to the same resolution of our images, making it ideal for us. When georeferencing you want to get your REMs error as low as possible. Anything around 2 or 1.5 is very good. I tried to get each of my image's REMS error to be around 2 as possible. After the images were georeferenced it was time to mosaic them together. To mosaic an image means to take several smaller images and stitch them together into a larger image. I could have used ArcMap to mosaic the images but instead I used Erdas IMAGINE. It took me about 2-3 hours to get this final image. Figure 12 is my final mosaic over laying the reference image.

Figure 12: Final image

Discussion:

We ran into several problems during this launch and during the post processing. The first problem that we ran into was that it had been very windy that day. Because of the wind our rig was thrown all around and did not take many perpendicular pictures. We need perpendicular images to have a successful mosaic. Figure 13 is an example of an image that is not perpendicular to the ground. While these are interesting to look at they are not useful when mosaicing.

Figure 11: A picture of campus and the River

Another problem that we ran into was the lack of ground points or ground references. Because of all the recent construction we did not have an updated image of what the campus green looks like right now. It is difficult to georeference an image without a good ground references points. It is possible by georeferencing one image very well. Using this image you can then reference the rest of your images by making sure they over lap by at least 60%.

Results:

 In conclusion there are many steps to in making a successful launch for taking aerial photos. It does help to have a lot of people so that these tasks can be split up into more manageable tasks. It is also important to do as much of the prep work before the actual launch date to save yourself headaches and problems. For the actual launch, you want to do it on a day that is clear and has little to no wind. It can take a long time to georeference your images into a good final image. You need a lot of patience and willingness to sometimes through out images to get a perfect final mosaic.

Assignment 8: Final Navigation

Introduction:

Over the past three weeks we have been working on learning different techniques on how to navigate.  We have then taken this knowledge and applied in out in the field. The first week we used the traditional method of using a compass and azimuth to navigate to points out at the Priory. We were also allowed to use a map to help us navigate. The second week we used the GPS to find a new set of points. We were given the coordinates of the points and using the GPS we were to find them without a map. In this final navigation activity, we are to locate all the points that we can in the three hour time period. To spice things up each student will be equipped with a paintball gun.

Study Area:

The navigation course was set up at the Priory which is located about 3 miles south of UW-Eau Claire. The Priory itself is located on a flat plateau surrounded by a wooded area. This wooded area is mainly made up of deciduous trees with a large patch of coniferous to the east of the Priory. The land drops swiftly north and east of the Priory. This year, Wisconsin has experienced a large amount of snow. During all three navigation exercise there was at the very least 6in of snow on the ground. Many times there was deeper especially on the sides of the hills. This made walking around in the woods difficult, most especially when walking up hill.

Methods:

These past few weeks we have gone out to the Priory twice and used a different method each time to navigate around to find points. The two methods that we used were map with compass and GPS. Each method has its own advantages and disadvantages.

Map and Compass

In our first exercise we used the traditional method of using a map and compass to navigate around the Priory. Before actually going out to the Priory, each group made a map that would be used out in the field. Over the map we put a grid. Using this grid we could then plot out where our points were. Also using the grid we were able to get the azimuth from point to point telling us in which direction we needed to be moving in. The map's scale bar gave us an estimate on how far to walk in a certain direction. While this method does work, it is time consuming, you need at least two-three people and does not work well when traveling long distances because it is easy to get of course. Figure 1 shows Stacy and Drew plotting out the points. Figure 2 shows Stacy measuring the azimuth from point to point.

Figure1: Stacy and Drew plotting the points

Figure2: Stacy getting the azimuth

GPS

For the next exercise, we left behind the map and compass moved to a new higher tech method of navigating, the GPS. We were not allowed any map or compass and were only given the coordinates of the points. Using the coordinates, we were to navigate and collect all five points. While this may seem like an easy thing to do, it takes a little bit to get used to using the GPS and knowing which direction you want to walk in. The advantages of this method is that it is highly accurate, simple to use and you only need one person. The disadvantage is that it is dependent on satellites. If you can't connect to a the satellites then your out of luck. Figure 3 shows our GPS and list of coordinates for the points. Also the GPS were keeping a track log so we upload our trail on to the computer to see how well we navigated.  Figure 4 is a map of our course.

Figure3: Garmin etrex GPS and our coordinates to the points

Figure4: Our final map of the track we took out in the field.

Final Outing

On this final outing to the Priory things were going to be a bit different. Instead of collecting points from just one course we were to collect all the points except for the the starting points. At each point we would take a waypoint with the GPS to prove we had been there. Like last time, each student had a GPS with them to record their path. To things more interesting each student was issued a paintball gun. Figures 5-6 show us getting our paintball equipment ready for the field. 

Figure 6: Zach is filling up on of the paintball guns with ammo

Figure6: Paintball equipment laid out and ready to be used.

 There was a five minute grace period so that each team was able to put some distance between each other. My team decided to start with the nearest point and work around in a circle to collect the rest of the points. We were able to stay ahead of other teams for a while but saw some action near point 6. We collected all the points but one.