Quarter 1 Journals
(11 Sept - 29 Oct)
| 2:30-3:30 PM | 1 hour | Cumulative hours: 1.0 | My Interview | 11 September 2009 |
Today, I had my interview at Johns Hopkins Applied Physics Laboratory. Because I was afraid of getting lost, my mother drove me to the building in which I had my interview (and will soon be interning). It is an incredibly easy drive from both Atholton and my home, and we had no trouble finding the correct building. I got there very early, and I met with Mrs. Finney and got my visitor badge. (Using the visitor badge to open the electronic gate-type thing was very cool!) Mrs. Finney told me to wear very comfortable shoes; the walk to the lab where we were going was very long, with lengthy hallways and a lot of stairs. In the lab, I had a meeting with three prospective interns; Chris Chiu, John Castelli, and Dr. John Samsundar. They were all very nice, but Dr. Samsundar did intimidate me a bit: he is a very, very smart man, and it shows. Although I was nervous, the meeting was a great learning experience and was very productive. The prospective mentors work on unmanned aerial vehicles (UAVs) and ways of tracking, and are all very busy. I do not know exactly what I will be doing when I start interning with my mentor, but I know it will be very interesting, and I hope I can be of some help to them.
Seminar (+1 hour)
Start-up Meeting (+1 hour)
Seminar (+1 hour)
| 1:35-5:35 PM | 4 hours | Cumulative hours: 8.0 | My First Day | 2 October 2009 |
Today (my first day interning at APL!) went incredibly well, and I was so relieved! Dr. Samsundar had so many different things for me to read, look at, and experiment with that I didn’t have a free minute – but I was fine with this, as I like being kept busy. He had found two different beginner-level packets of information about MATLAB for me to look at, and he had installed MATLAB on the computer for me to experiment with. He had even, keeping in mind the presentation that I will be doing in November, gotten out a huge binder from a class he had taken on public speaking. As you can imagine, I was definitely kept busy! After reading important parts of both MATLAB packets (while simultaneously typing commands into MATLAB and testing its amenities), I had begun to look through the binder about public speaking when Dr. Samsundar arrived back from his meeting and showed me the GPS device that I would be taking home and using. It is very small, affordable, and useful – you can plug it into a computer and see its data points (where you traveled) on Google Earth! He told me to test it out at home, and show him what it could do the next time I intern.
| 8:00-9:00 PM | 1 hour | Cumulative hours: 9.0 | GPS work at home | 7 October 2009 |
Today I decided to spend some time at home working with the GPS device Dr. Samsundar had given me. After installing everything on my computer at home, I discovered the many different settings that you can put the device on; for example, you can set it to record its longitudinal and latitudinal data points at any time interval you want (the default is every second), or even set it to record the coordinates every certain distance (the default is 5 meters). I decided to test the device by going on a quick walk around my block at night, having the GPS record data points every 30 seconds. When I plugged the device back into the computer, I could see my (almost) exact route on Google Earth! It was really cool to see this, and I was excited to show Dr. Samsundar. However, it was evident that there were major uncertainties with this device; when showing my track on Google Earth, it showed a path where I crossed the street at one point (when in actuality I did not) and it even showed a track through someone else’s backyard (when I obviously did not cut through any backyards). The uncertainties of GPS that Dr. Samsundar described were evident even in my quick experiment.
Seminar (+1 hour)
| 1:35-5:45 PM | 4 hours | Cumulative hours: 13.0 | Second Day | 9 October 2009 |
Today was another very productive day at APL, although a lot of time at the beginning was spent trying to get internet on my computer to work (which involved my mentor calling/getting annoyed with the help desk, and bringing in 3 different “computer guys” into the office.) The help desk said they would try and send someone over within the next few days, so I worked without internet for the day. He left me to again experiment with MATLAB, and he gave me my first task: to load and graph a file with about 2050 data points on MATLAB. This was a simple program and I finished it quickly. Later, I got to show Dr. Samsundar my quick experiment (described in Journal Entry #4) on someone else’s computer (because it required internet to show the points on Google Earth). He was impressed, and he was also interested in the uncertainties that were seen in the device. He told me to, as a sort of homework assignment, set the GPS device outside and not move it for about 10 minutes, while it records GPS coordinates every second. He explained that when I read the coordinates on the computer or look at them on Google Earth, it will be obvious that the GPS device is not as accurate as it could be – points will range from little to many meters around where the device was actually placed, as opposed to the device only reading one constant set of coordinates (which it would ideally).
Seminar (+1 hour)
GPS work at home (+1 hour)
| 1:35-5:45 PM | 4 hours | Cumulative hours: 19.0 | MATLAB | 14 October 2009 |
It was an interesting and productive day at APL. Today, I again worked with MATLAB -- I wrote a program that reads in three columns of data (presumably latitude coordinate, longitude coordinate, and altitude) from a text file document. This is an important skill because now, when I have data in column form, I can manipulate the file in many different ways with MATLAB (I can find data such as the range, mean, mode, etc. of a column or I can convert data into other forms such as geodetic form or ECEF form). It was decided that I will bring the GPS logging device on my trip to Boston and Brown, and I will record data every 15 seconds of my trip. We will read and examine the data (in column form and on Google Earth) soon after. I am becoming more and more familiar with MATLAB, and I even impressed my mentor with some coding information that I remembered from taking notes while looking through the MATLAB packets.
| 1:35-5:45 PM | 4 hours | Cumulative hours: 23.0 | MATLAB code | 22 October 2009 |
Today at APL, I again worked with programming in MATLAB – only this time, I had my own data that I could manipulate! My mentor showed me a MATLAB program written by someone else at APL which takes latitude, longitude, and altitude and can (similar to what the device can do) plot your trip on either Google Earth or Google Maps. I put the data from my trip in column form and had the MATLAB program read my data. After having to make one column negative (because of a reason I was unsure about), my data was displayed correctly on Google Earth! It was interesting to look through the program, which helped me to further understand how the device can plot its data and which helped me to familiarize myself more with MATLAB code. It was decided that my next “homework assignment” would be to set the device down in an open area for 15 minutes (recording data points every second) and see easily the uncertainty that the device holds – will the data points all be almost identical, as they should be?
Seminar (+1 hour)
| 1:35-5:45 PM | 4 hours | Cumulative hours: 28.0 | Statistics with MATLAB | 29 October 2009 |
Statistics is one of my favorite classes this year, so it was great to be able to use what I have learned in class while at APL today. Today, using data from my “static” experiment (where I placed the data logger in one unmoving place for 15 minutes and recorded data points every second), I created a program on MATLAB that found the mean and variance of each column of data (latitude, longitude, and altitude). This way, I could see how comparable the data points actually are with each other. When viewing the data from this experiment on Google Earth, it was very interesting to see how dissimilar the points seemed to be (shown above). Keep in mind, the data logger was in one unmoving place for 15 minutes (in front of my house, which has the blue car in the driveway), although the data logger shows points seemingly very far away from this point. Possibly, conflicting signals made the GPS signals less accurate; this experiment, without a doubt, showed some major problems and uncertainties with GPS data.