Located at the Fick Observatory near Boone, Iowa is an 8.5 meter parabolic dish antenna. The restoration of the antenna has begun. The mechanical restoration is at the point where the dish can be hand cranked in both the altitude and azimuth directions. The following months will be used to install a receiving system and the control system as well. Following software implementation and receiver calibration, computer control of the radio telescope will be implemented to begin radio astronomy.

PROBLEM STATEMENT

Following the mechanical restoration, outfitting of a microwave receiver, and implementation of the control system, the next step will be to improve the quality of the receiver and control equipment. Calibration and stability of the receiver will be the focus of the receiver improvement. Control will be improved by new technology and improved software. Clean-up and outfitting of a control room at the Fick Observatory will give us a place to operate.

DESIGN OBJECTIVES

• Outfit the antenna with the receiving equipment.
• Calibration of the RF receiver.
• Determine temperature stability of receiver.
• Install low-loss coaxial cable
• Construct the system to control the positioning of the dish.
• Restore the operations and control room at the Fick Observatory.
• Integrate the control and receiving equipment to be operated by a PC at a remote location on campus.

The parabolic dish antenna has been restored to mechanical working condition. The control system has been researched and the next step is to install the system. Once the system has been installed it will need to be tested and made operational. Computer software will be written and used for tracking. Initially the control will be from the Observatory Control Room that will be cleaned-up and outfitted with the necessary equipment for operations.

This project involves the knowledge and understanding of receiver systems. A superheterodyne receiver will be installed on the radio telescope. When this receiver has been installed and is operational it will need to be tested.

Receiver calibration is the first jump to a nominal system. Calibration is used so that when an RF emitting source is observed, one can convert the data to calculate an intensity of the celestial source accurately.

Calibration starts by using the output from the receiver, which is a voltage. Then that voltage can be turned into a number that can be related to the intensity of the celestial source doing the emitting. A common way to do this calibration is to calibrate the output in terms of an input temperature. This can be done by installing a noise source at the antenna in the receiver box. This noise source has its intensity calibrated in terms of temperature. From the control room one can switch between the connecting antenna to the receiver input or connecting the noise source to the input of the receiver. By switching back and forth we can compare the noise source to the antenna signal and hence develop a calibration scheme.

Once we have developed a calibration scheme the next point of attack will deal with temperature stability of the receiver. The temperature must be stabilized to keep the gain of the system from drifting. If the gain drifts one can’t tell the difference between the gain drift and a change in intensity from the celestial radio source.

Temperature stability can be accomplished in a number of ways. Some of those may include insulating the receiver, liquid cooling, or just putting it in a controlled environment.

Of course, it would be necessary to feed back the coordinates of active locations to the software. This would be accomplished through the use of a feedback system. Resolvers will be used to obtain this information from the dish mount, then through a resolver-to-digital converter of 12-bit resolution will be transmitted back to the on-campus computer so that we can monitor the dish’s location.

Along with transmitting the location data would be information from the receiver. The software should incorporate analysis of receiver data to track strong signals as the earth rotates.

PROPOSED BUDGET

The budget allocated to the radio telescope project is $15,000 with $5,000 that can be petitioned for. The budget is kept at the Iowa Space Grant Consortium (ISGC) Office. Rough estimates for purchase this semester are approximately $6,000. A detailed itemized list will be drawn up as the project progresses.

PROPOSED SCHEDULE

Refer to attached schedules with respect to semester.
Attached:
                Semester Schedule 1
                Semester Schedule 2

CLIENT
 
 

PROJECT ENGINEERS

Eric K. Davis       422 Stonehaven Dr. Apt. 18
                           Ames IA 50010
                           515-233-3064
                                   ekd@iastate.edu
                           EE 461

Rod Schmidt       422 Stonehaven Dr. Apt. 18
                           Ames IA 50010
                           515-233-3064
                                   rschmidt@iastate.edu
                           EE 461

Brice Jensen        3430 Woodland St.
                           Ames IA 50014
                           505-296-4929
                                   bajensen@iastate.edu
                           EE 461