James R. LeMire Arnold E. Lupe Jr. Oscar Munoz
University of Texas at El Paso
Dr. Jorge A. Lopez PhD Physics Dept.
Dr. William G. Durrer PhD Physics Dept.
Dr. Joseph H. Pierluissi PhD Electrical Engineering Dept.
This project consists of building a radio telescope, using a very small array
of two to four 8’ satellite dishes. The telescope will be used by the Physics Department,
University of Texas at
· Construct a Radio Telescope using a small array of satellite dishes
· Targeted receiving frequency of 1420 MHz +/- 600 KHz
· Project Completion; April 2004
· To remain within our sponsors $5,000 budget
· Meet all project deadlines in timely and efficient manners
METHOD OF COMPLETION
Our team will attempt to build a radio telescope using two to four satellite antennas formed into a linear array. The signal of the antennas will be combined, and connected into a hydrogen spectrometer. The spectrometer will then display the data as a function of time vs. frequency.
To solve the problem, our team organized itself into three technical sections. Carlos Munoz is working with interferometry and radiation patterns, James LeMire is responsible for the antennas, transmission lines, and the amplifiers. Arnold Lupe is handling the output of the signal from the spectrometer to the display.
A linear array pattern allows the Radio Telescope to focus in on a single frequency. This radiation pattern will create one central lobe, in order to keep the beam width at the smallest value possible. The beam width, which is the angular width of the radiation lobes, will need to be at about 1 degree. This pattern will provide the antenna's feed horn with the best possible lobe with which to gather information.
The telescope will be placed on top of the
250 feet of coaxial cable will be attached to each satellite with Low Noise Amplifiers (LNA) emplaced at 50-foot intervals. The amplifiers are to ensure the data will reach the Spectrometer since the cable has a attenuation factor of 10 dB per 50 feet.
Once at the Spectrometer, the data will then be converted to a 70 MHz signal. From this point the data will be interpreted by the Spectrometer’s software at a rate of 2400 baud, for an 8 bit data form. This will result in a visual graph of the incoming 1420 MHz Hydrogen line spectrum. The graph will be displayed as a frequency vs. time scale with a +/- 600 KHz to accommodate the Doppler Shift.
This initial emplacement will provide the Physics Dept with an initial reference point to collect and interpret the data. Additional adjustment will be made as needed by the Physics Dept.
Developing testing procedures to insure accuracy of the antenna radiation pattern
· Obtaining two additional antennas to strengthen the interferometry to improve the Radio Telescope's resolution.
· Transportation of the dish antennas to the projected location.
CURRENT STATE OF PROJECT
The team has obtained enough peripheral equipment to support two satellite antennas. However, with only one antenna feed-horn it would be difficult to accurately test all equipment. A single antenna will only provide a wide central lobe. This wide central lobe will yield a poor resolution at the spectrometer output, which is not ideal for frequency specific data research.