DeSPIRAtion to understand DSPIRA

DSPIRA

Digital Signal Processing In Radio Astronomy

The easy part- RADIO ASTRONOMY

This is the branch of astronomy that explores the radio end of the Electro-Magnetic Spectrum (EMS). We “SEE” the Sun, Moon, stars and planets in the sky with our eyes, and with the assistance of telescopes, because our eyes are sensitive to the VISIBLE LIGHT portion of the EMS. We are familiar with the other parts of the EMS such as X-rays, Ultra-Violet, Microwaves, RADIO, but we don’t SEE them directly. Things in space generate Electro-Magnetic Radiation right across the full EMS. We need special detectors to see them.

Electro Magnetic Spectrum

SIGNALS

"Signal" has become a very common word in everyone’s everyday vocabulary. Thing about the last time you used that word. It was probably something like, “Dad, why are we on vacation in the mountains? I can’t get any signal for my phone”, or “My signal strength in 4 bars.” Simply put, SIGNAL, in this context, IS Electro-Magnetic INFORMATION. Nearly the whole of human knowledge and information is available through your cell phone. The signals are “in the air”, or at least available to be generated at your whim. If you ask SIRI, “What time is the sunrise today in Sunrise, Florida?” Your phone will generate a RADIO SIGNAL that travels at the speed of light to a receiver. The information you requested will be retrieved from a computer somewhere and turned into a RADIO SIGNAL that will be transmitted back to you…all in a matter of seconds. Now, if you go out on a clear night and see the Full Moon, you might not consider that a SIGNAL, but it is. Light from the Sun is reflecting off the Moon and travelling to you where you get enough information for your brain to PROCESS (coming up) the Signal enough to recognize it as the Moon.

SIGNAL PROCESSING
The signals are everywhere… It is currently a beautiful day outside. The Sun is out, the sky is blue, there may be some clouds out there…or so I think, because I am sitting inside with the shades pulled typing this up now. If I step outside and use my eyes to receive the signals, and let my brain PROCESS the SIGNALS, then I will know for sure…I am going to take a quick break and go outside to process some signals…

…Yep, I was right! Oh, and I used the digital camera to capture and do some DIGITAL SIGNAL PROCESSING so I could share with you what I saw.

The science of astronomy is all about signal processing. We sit here on Earth with a very limited capacity to travel to all these exotic objects we see. Astronomers have to use telescopes to SEE the universe around us. The telescopes mainly look at selected objects and record huge quantities of data in computers for the scientists, or their computer software, to sort through the data to help us discover the Universe. An example of the huge quantity of data gathered in astronomy...The New Horizons space craft passed by Pluto in July 2015. It spent a few precious hours in close proximity to the (dwarf) planet where all the instruments were busy receiving signals. It took the spacecraft until Oct 2016 for all the data to be transmitted back to Earth. The Data Processing will go on for years to come.

Pluto Data Dump

DIGITAL SIGNAL PROCESSING

The DIGITAL part is simply that we use computers to aid us in processing the data. Here is an example of using a digital picture I took, and using a photo editing program to PROCESS more information from the original SIGNAL.