New Clalibration Data

This week I performed the same calibration technique as the last time with a few precautions. I timed the measurements to make sure that there was a roughly equal number of data points in each. I also made sure that nothing else passed through the view of the receiver during measurements. This new data set is more consistent but has an outlier. The plots show that there is no correlation between signal strength and angular orientation of the calibrator. This set also indicates that the 100cm measurements had a stronger signal. This might be caused by interference with the receiver that occurs when the calibrator is placed too close. 

The outlier is the 180 degree, 100cm measurement. The other measurements have signals within the same range between 0 and 50Hz which is reasonably precise. Yet the 180 degree, 100cm measurement still follows the trend that the 100cm measurements have stronger signals. 

In the coming days I will meet up with Dr. Hassel to further interpret the plots. I will also begin to familiarize myself with the arduino that Jonathon Farrell had created during the summer of 2016. His blog, detailing the setup, can be found here: http://sienaviper2016.blogspot.com/

Once I am competent in implementing the motor controls on a smaller motor I will move on to the motors for VIPER.

Calibration Data

During the Fall semester of 2016, I began developing a calibration technique for the telescope's receiver. Using a calibrator that emits a radio signal, I took 12 measurements of varying angles and distances while toggling the power to the calibrator.

This week I took the data and plotted it. I compared the measurements of corresponding angles to see the relationship between signal strength and distance from the receiver. The following plots represent the difference in signal from when the calibrator is turned on and when it is turned off. The specific parameters of the measurements are indicated in the title.

                             

The data seems to be fairly inconsistent. When comparing the signal of similar angles but different distances, The 180 and 90 degree measurements indicate that the closer the calibrator is, the stronger the signal. This is intuitive and makes sense. However, the 45 degree measurement indicates the opposite and thus the data is inconsistent. This could be due to a small data set as well as not taking careful enough measurements. There were people coming in and out of the room who would walk in the view of the receiver and this could easily cause problems. In addition there does not seem to be any correlation with the signal strength and the angle. I plan to retake the measurements more carefully and try to find a pattern that will enable us to discover the best method for calibration.

Connecting the Arduino to MatLab

During the the Fall semester of 2016, I primarily focused on operating the arduino software to electronically control the motors of Viper. There were many challenges with getting MatLab to recognize the arduino. The primary problem was that Linux identifies ports differently than mac or pc and so I had to take a few extra steps to connect MatLab with an arduino. Following the instructions from the following websites successfully established a symbolic link that MatLab could recognize:
http://www.matlabarduino.org/serial-communication.html

http://www.howtogeek.com/199687/how-to-quickly-create-a-text-file-using-the-command-line-in-linux/

https://www.mathworks.com/help/supportpkg/arduinoio/ug/find-arduino-port-on-windows-mac-and-linux.html?requestedDomain=www.mathworks.com

Project Abstract

The VIPER telescope was donated to Siena College and has been a work in progress for a few years now. VIPER is a radio telescope with two focal points. The primary dish refocuses the incoming radio waves to a secondary mirror which focuses the light to a fixed point on the telescope. During the summer of 2015, I worked on VIPER and mounted a signal receiver to the secondary focal point. The primary goal of this project is to reverse engineer the software that came along with the receiver in order to allow further improvements and customization of VIPER. As of right now the receiver can detect radio waves that have a wavelength of 22 cm. If we can understand and change the code, we can then alter the receiver so that it can detect other wavelengths and conduct various observations without being limited to specific sources. The secondary goal is to actually obtain a measurement with the receiver. The plotting software produces three different plots. One is power vs time, one is instantaneous power vs frequency, and the last is average power vs frequency. The sun is a source of 22cm light, however it is a continuous source as opposed to a discrete source. This causes the plot of the spectrum to increase continuously and in turn skews the plot of the average power vs frequency. We would like to observe a discrete source because the plot will remain constant and enable us to properly calibrate the receiver. I built a calibrating device during the same summer and it will be crucial to develop and implement a calibration technique for the receiver to ensure accurate data. A team at Union College has also built the same type of receiver and cross analysis of data can help in confirming that the VIPER telescope is at optimal functionality.