Day 30

We spent today practicing and refining our presentations, practicing in the auditorium and in front of Dmitry. Emily, Paige, and I listened to Peter and Ashley present in the auditorium and gave them some constructive comments, mostly helping with different formatting and slide-layout problems. I myself practiced going through my description of our setup, to create a clearer flow of my description of the visuals. Now that I've fixed that, everything is running smoothly, and I'm ready to go for tomorrow.

Everyone's presentations are looking really good, I'm excited for us to present tomorrow. It was a little sad that this was our last real day together, but it's been a really great six weeks, and I couldn't have asked for a better group of interns to spend it with. It's been truly incredible, having the chance to participate in substantive research, doing something that will contribute to the scientific community (eventually we'll be sending our data to NASA!). This research is so interesting and I'm so glad that I'll have the chance to keep working with Dmitry after tomorrow. He invited me to come present my research at the IONS conference this fall, which sounds like such a great opportunity! I'll have made some more progress by then, and there will be so many people there, all interested in the same sort of science as me. It'll be so cool to talk to scientists who are so much more experienced; I'll be able to learn so much from them. It looks like a big conference too, it's hosted by the OSA (Optical Society of America).

Day 29

This morning, all the way up until lunch, we shared our presentations with the other interns and presented in front of everybody else plus Joe and Matt. So today was essentially our practice day, and everything went pretty well; Joe approved of everyone's presentations overall, and he and Matt gave some constructive remarks while we asked each other questions about the presentations. My presentation went really well, I was exactly at 10 minutes, and I just needed to tweak a few things. I took some of the time I spent on background and introduction and used it to instead elaborate more on our future research plans and next steps.

This afternoon, after editing my presentation, I presented it to Dmitry, and he thought it was much better than the first rough draft, and that it was coming along really nicely. Dmitry gave me a few pointers and things to improve upon, which I spent the rest of the day working on. I'm now feeling good about the presentation on Thursday; I'm really excited to share my research.

Day 28

Today I finished the new and improved version of my presentation and showed it to Dmitry. While he did have a couple tips and pointers for things to fix, he said it was quite a bit better than the first attempt. I've made sure that my slides are now better organized and flow more easily, I even added in some animations to describe Kepler's pixels, graphs comparing my results, a GIF (an artist's rendition of an exoplanet rotating on its axis), and a short video showing the motion of a transiting exoplanet. I spent a good deal of time making sure all my sources were properly cited, and took close up pictures of different parts of our setup to include in the presentation.

I was about to transfer the file onto a flash drive to give to Joe, but my flash drive (which is pretty old) stopped working. I figured my best bet was to head to "The Hub" and buy a new one, so I plugged it into Google maps and followed the directions for half a mile to the other side of campus, only to find that it had led me to a post office. The Hub, it turns out, was only a minute's walk away from our building, right next to Bytes; so I walked back across campus and luckily I was able to find a good flash drive there.

Day 27

This morning I took some pictures of each part of our setup for my presentation, before moving on to analyze the different Gaussians. It appears that the spot without the glass is about 3.2 pixels wide at half maximum (about 20 microns) while the spot with a 0.122 in glass window is about 3.5 pixels across (about 23 microns). In addition to being a sharper image, the spot is a fair amount brighter without a window impeding it.

For the rest of the day, I worked on my presentation, and practiced it with Dmitry around 3:30. He gave me some really helpful advice on making a good presentation and organizing it properly.  We spent a while going over how I could improve it, and then I spent the rest of the day working on my presentation. I'm going to finalize everything this weekend, so that I can be ready to get it in to Joe on Monday. I also asked Dmitry about continuing to help with research after the internship is over, and he said that I can do that! This project is so interesting, I'm really glad that I'll get to do a little more on it this summer (and maybe fall too?).

Day 26

I spent this morning comparing the encircled energy graphs which I created for our various datasets (for each window thickness). The coverslip, microscope slide, and no glass all look pretty similar, which is great, but the thickest (and most realistic) glass appeared to be almost double the size. However, we realized that this could have happened because our spot is so dim and small, it's below the Nyquist frequency, so data blurring may have given us a response that appeared to be larger than the spot of light actually was. Because of this, we decided to next try to map Gaussian functions to our original data, but magnified with interpolation, which we would do after lunch.

After lunch however, Dmitry asked the three of us to help disassemble his telescope, mount, and tripod, all of which he'll be taking to Oregon to observe the solar eclipse in a week and a half. We spent the afternoon taking down the assembly and packing it very securely into Pelican cases.

Our original configuration had the heavy mount on the bottom of the case, with the refracting telescope arm and the cables on top, separated by a layer of protective material. That was how we brought the telescope back down from the roof, but Dmitry later realised that it would be both safer and more efficient to ship the telescope in its own box and to put the counter-balance weight in the case with the mount and cables. I stayed late today, until about 7, so while Dmitry went to a meeting, I mapped Gaussian functions to each of our datasets and plotted the different fitresults together on the same graph for comparison. Luckily, in measuring the data this way, the 0.122 inch thick glass seemed not to do as badly as it had with the encircled energy calculations.

Day 25

I spent today writing code to analyze our data from the past week or so. Originally we tried mapping Gaussians to our data, but because we were on a logarithmic scale, most of our data points were negative, because our spot is very small and dim. Unfortunately, the Gaussian fit function in MATLAB does not deal well with negative numbers, so it mapped a Gaussian function to only the very few pixels around the center of our PSF and ignored the rest of it. Fortunately, there are many ways to acquire the data that we need, so we were able to calculate the encircled energy of each of our datasets. Encircled energy is, essentially, how much of the total energy (as a percentage) is contained within any given radius from the center of the function. We can calculate the approximate radius of the spot by finding the radius within which 90-95% of the data is contained.

Without a window in front of the sensor, the function looks like this, with the radius being about 15 counts wide, about 1.5 pixels. The function looked quite similar with a coverslip and a microscope slide, but looked a fair amount wider when it came to the thickest window.

Originally we saw a dip in the plot, which was odd, because we should not have the energy decreasing as more of the function is included; that could only happen if we had negative pixels.

Upon closer investigation, it appeared we did have negative values in an oddly uniform pattern around the spot. These negative values occurred because we magnified our data, multiplying our x and y axes by 10 each, leaving the algorithm to interpolate data for the new points. It turns out the default setting takes values from the nearest 4x4 group of pixels, which can lead the graph to believe there is a larger downward trend than actually exists in the data, and can give us values outside our original data range (in this case, meaning negative values). I was able to fix this by altering the settings to take only data from a 2x2 pixel neighbourhood for interpolation purposes.

Day 24

This morning we walked around the RIT campus, trying to find a microscope slide to use for our medium-width piece of glass. We first tried to find one in the building where the construct is, but then Dmitry remembered that the guy we were looking for had already graduated, so he was gone. We then tried to borrow one for the engineering building, but they refused to let us, on account of us "being from another college." Luckily we were able to find one in Gosnell Hall, so we brought it back to the lab. I was able to run our program after homing and focusing our setup, and we were pleasantly surprised to find that the resulting surface function was quite similar to that of the function from the thinner glass. It was so similar, in fact, that Dmitry had to take a couple minutes to figure out which was which when I asked him if he could tell.

Unfortunately, our fancy new camera will not be coming for another week, so I won't actually get to use it since presentations are due a week from today. While that is a little disappointing, it's alright, if we make good progress tomorrow, we should be able to take a few images with the Kepler camera, which I'm excited to use.

Tomorrow we'll be fitting curves (most likely Gaussians) to the data I took today. Besides the data from the images with the microscope slide, I also took two more sets of data with no glass cover and with the thin glass (a coverslip) as a second trial where I was much more careful to have our spot of light be in as exact focus as I could manage. Tomorrow we'll compare the two sets of data, and determine the effect of the window thickness and the differences in accuracy of focus.