Radio Telescope

Abstract:

In this study, the goal was to create a map of the sky on the 70cm band. The hypothesis is with the use of special antennae, software, and radios to make a higher resolution map of the sky at lower frequencies and to combine the collected data with other surveys to create a higher resolution map of the sky. In radio astronomy most of the work is done on the 21cm band however not much research is done on lower frequencies (70cm band areas); as a result, there are not very high-resolution maps of the sky at 408MHz. The goal is to both collect data locally and to also use other data from other surveys to create a hybrid map with an even higher resolution due to the combination of both datasets. The method of data collection is to use a radio telescope which is both recording strength values, tilt and the bearing of the telescope itself. When looked at individually the data found was accurate when using other surveys to compare to. Additionally, when using the hybrid map a greater depth and resolution can be seen in the combined map. The hybrid map can be used for more research on objects that are known to exist but we know little beyond that. And with this increase of information perhaps more discoveries in the field of radio astronomy can be done such as observing and identifying unknown radio sources or looking at how galaxies, stars and planets form.

Introduction:

The goal of the project was to create a radio telescope for radio astronomy. Radio astronomy is basically like regular optical astronomy but you’re using radios to “look”. It boils down to having a directional antenna and what is basically a fancy voltmeter which collects the strength values of the telescope alongside another system that record where the telescope is looking. Then when you have many other these data points you can create a radio strength map of the sky. Typically radio astronomy (particularly amateur radio astronomy) looks at the Hydrogen Band which is simply just another wavelength and thus a different part of the spectrum. However, in this project I used the 408MHz band which is basically part of the 70cm band. The reason this band is less used is due to the fact that the smaller the wavelength they easier it is to stop a radio signal; as a result it means that the strength values are harder to record accurately than in other parts of the radio spectrum.

Why is radio astronomy important?:

● With the hydrogen line it can look at the cold clouds of gas

● In the 21 cm band it can map the structure of galaxies

● Learn about supernova

● Radio astronomy can go though t the dust in the universe allowing for us to look at things that can’t be optically thought traditional telescopes

● Radio astronomy has detected many new objects; pulsars, quasars and galactic nuclei and, of course background radiation

● Other things radio astronomy has discovered; the first 5 planets outside the solar system, the births of stars, the complex distribution and the evolution of galaxies in the universe; observing the creation and the distribution and the heavy elements which is essential to the formation and building of planets and even life itself

Methods:

The method of collection of data started with the creation of the antenna itself, which was constructed based on omnidirectional type antennas which are very efficient when point at the desired radio source. The actual antenna itself was designed for 408Mhz (which is close to the HAM radio 70cm band). The deigned of the antenna was made by using the formula for creation a horn antenna. After the antenna was created and deigned a simple rotation mount was created allowing for the antenna to point in any axis to record data. Next I added an electronics module which I had already created with an accelerometer, gyroscope and a compass and attached this module to the boom of the antenna arm. When the electronics package was attached it meant the telescope could now point anywhere and know where its pointing. At this point all you need is an open source SDR (software defined radio – basically a radio that can tune to any frequencies) and some software to import the data that was collected. The software that was used was the open source image editor gimp for its use and importation of .FITS files. This allowed for the combination with other sources and the post-editing of my own data collected. After the data was collected and processed, I converted the .FITS files into .PNG(s) from there basically photo editing as applied to enhance the image quality and to boost the data that was collected so it could be seen more easily.

Conclusions:

Through the combination of data from both surveys an increase of resolution can be seen in the data. Because of the different observation conditions and locations. It is a step forward in the research in the lower frequencies of radio astronomy. Moreover, the similar data can be used to verify both results due to their similarities in their findings. Overall, as a result, the new map of the sky can hopefully be used to discover more in the universe.