Delta Aquarids?

Yesterday late afternoon showed the sort of signal I was expecting from meteors.  At around midnight there was a longer lasting event.

The night before had nothing to show on it.  This is what most of my data looks like, I need to find some data to confirm my readings.

The Perseid meteor shower will peak on 12th August and this should be more intense than the Delta Aquarids.  It will be interesting to make the comparison between them.

Delta Aquarids

Last night was a bad night for observing meteors too many clouds so delighted that my over the horizon radio system seems to have picked up all the action.  For over a month I have detected next to nothing but now we are in meteor season I am expecting lots more like this.  All of the null data when there was nothing much happening validates this observation.  I will post tomorrow the results of tonight's observations.

East to West sky image

Not much to look at yet but this is the East to West image of the sky in microwave wavelengths. The altitude is 22 degrees. Each bright line is the signal from a satellite. This is a one pixel wide image and the very slow plan is to increase the altitude and do it again repeatedly until we have a map of half the sky.  This reminds me of watching pictures slowly appear on old school dial up internet connections. 

First Something

After days of just background hiss this morning when I checked on the ionosphere experiment I found a blip that was exactly what I expected to see. 1 minute and 34 seconds of tuned into a radio station I cannot usually connect to.  This should be because of a disturbance in the ionosphere.  What caused it? Space Weather told me that there was very little going on and less than a 1% chance of anything at all.  I can't wait for the Delta Aquariids in late July to find out if this is what a meteorite looks like.

Set-up Details

I have been asked to give a bit more detail of the setup for my satellite dish telescope.   I purchased the satellite signal detector from Amazon

The detector and the LNB require 13V (a range of voltages work. I have not tested the limits) to work.  This is usually supplied by the receiver box so has to be supplied.  This is my set up in bench testing, looking a bit crude but working.  The bent paper lip is at +13V the core of the coax from the LNB is pushed into the connector.

To turn this into a measurable signal I used an old crystal microphone an amplifier board and a multimeter that could measure a.c. In the mV range.  I would say that all of this equipment has been in the school since the 1980s. 

It would be easy to use a computer mic and a laptop to do the same job but this looks like science to the pupils.  Each measurement has to be done by hand so the pupils have a better feeling of how the system works.

To identify the satellites we use LyngSat.com which has details of satellite positions relative to your position and info on what channels they carry, this seems to be the most fascinating bit to the pupils.

Interesting double spike in hiss

The FM radio data is hard to interpret and I have to confess that I do not know what I am looking at.  After a couple of days of hiss and the occasional but regular small spike, which I think is just local noise, I found these interesting spikes.  The two spikes had a very high amplitude.  The background hiss has an average of 880 on the y scale (I have not found out the units yet so don't red pen me) the spikes went up to 11880 for the first and 13845 the lows in the dips were around 40.  I think that the lows are caused by locking onto a carrier wave and could terfore be an indication that my experiment is working.  The dips lasted around 2.5 seconds and were separated by 24 seconds.  I have no idea what I detected.

Meteorite and other Ionosphere disturbances

While a satellite dish looks like a radio telescope it is not the only way to go about observing in radio frequencies. A radio tuned off station produces a hiss and that is my starting point for the next project.

I used an old mobile phone with an FM radio app installed as my radio reciever.  This was connected via the mic in port on a little notebook I use for physics stuff. The software used was Radio-SkyPipe This records the amplitude of the signal at a slow sample rate so you can record for days without filling the hard drive.  That's it cost me nothing in new stuff and used only things I had lying around.  I have plenty of other FM radios if I think that the mobile phone is not suitable for the job.

I set the radio to 89.3MHz this is the frequency of radio Belfast and is not received in Edinburgh. Listening through headphones all that is heard is a very monotonous hiss.  A disturbance in the ionosphere such as a meteor striking the upper atmosphere  or a solar storm can cause the radio waves from the transmitter to be reflected off the ionised gas and received by my radio.

I picked a quiet night to test the set up.  There were no solar storms and no meteor showers forecast.  This would give me a good baseline to use as a comparison.  As expected I got very little variation in the hiss but at first look I saw some spikes in the trace. This got me excited until I saw that they were quite evenly spaced.  Every 1 hour 2 minutes something in my setup causes a small spike 20% above the hiss.  This is good to know so it can be ignored when if I get some proper signals.

If anyone has successfully got results with a setup like this I would welcome some advice. I will post any interesting results I get from this project.

Getting Started

I am a physics teacher at Liberton High School in Edinburgh Scotland.  I have been running an astronomy club on and off for a number of years but have been frustrated at the limited ability to do observing during the school days.  In recent years we have only been ably to take our optical telescopes outside during December.  A clear sky in December after school when there is nothing else on is a rare event.

Radio astronomy offers a chance to do some real science all year round so I decided to investigate what could be done.

Microwave Telescope Project

Small satellite dishes are readily available.  A quick email round the staff at school got me 2 dishes the next day.  I purchased a satellite finder from Amazon for less than £10 connected it to one of the wires from the dish and powered it up.  I bench tested it with the school's 2.8cm microwave transmitter. The results were great and I could transmit a strong signal across the room.  The normal experiments have a range of less than 1m.

Next, turn it into a radio telescope.

The dish was mounted on a party susan rotating table.  A compass scale was placed underneath and aligned.  A stick was attached to the arm to point down to the scale.  The signal detector makes a noise when it picks up a satellite signal.  A microphone and amplifier were used to produce a voltage which could be used as an indication of signal strength. Switching on produced a series of loud beeps as the dish was rotated. Time to do some science.

First Light Data

Yes! we have a scientific instrument which has a resolution of 1 degree and can pick out satellites.  Next task is to do a 360 degree sweep and work out how to measure the altitude we are pointing at.  After that a sky map.