Radio Astronomy

First successful detection of meteors by radio scatter using FunCube Dongle Pro Plus Software-Defined Radio @ LRO

Success at last!

In spite of all the positive posts around meteor radio scatter I have posted recently, one thing I had not managed to do was to use my FunCube Dongle Pro Plus software defined radio – this has been my aim as I do not wish to leave my (expensive) Yaesu FT-817 turned on and plugged in long term.

Today, is the first time I have managed to that using Dell E6400 laptop, Spectrum Lab software, USB 1 extension cable, FunCube Dongle Pro Plus, Bill Watson’s feeder cable, Bill Watson’s Slim Jim aerial tuned to 143.049MHz on 4 poles mast outside log cabin at LRO (4 old trampoline steel poles – total height 4-5m).

The following link gives an account of my success and suprising failure with same setup using rear mounted Moxon tuned to 2m band (rich text file):

Radio Observing Log Dell E6400 010517@0907

Configuration file used on Spectrum Lab for above detections:

Meteor Detection 2017-05-01@0838(Dell E6400) (this is a ZIP file – WordPress will not allow the extension to be attached to this entry without being zipped first – to use this unzip the file and save the configuration file in your Spectrum Lab configuration folder).

This successful use of the FunCube Dongle Pro Plus occurred with both FunCube Dongle Pro Plus and Yaesu tuned to 149.049MHz. I used SDR Sharp to set upper side band on FunCube and Yaesu also on upper side band.

Andy

Meteors detected using above setup between 08:27 & 09:17 (gives idea of frequency and how successful this has been):

 

My best detections of meteors ever by radio scatter at Rosliston Forestry Centre Science Event 29/4/2017

During the science day, the RAG team helped my erect a 4.8m ex-military aerial (purchased from ebay few years ago for around £30) – I attached to the top of this Bill Watson’s homemade Slim-Jim aerial, purpose-cut for 143.049MHz. Using my Yaesu FT-817 radio, I set about trying to detect meteors from Graves radar in France by radio scatter at 143.049MHz upper side band and……….

My best detections ever!! The meteors were coming thick and fast – sometimes 3 on the screen at any one time on Spectrum Lab! I have NEVER detected meteors so well as I did today. A true WOW! moment.

Below are pictures from the event and some examples of meteors detected (WSJT-10 and Spectrum Lab software screenshots) – a more comprehensive account of meteors detected can be found in PDF format by clicking of this link: Meteor detection screenshots 290417

Andy

Photos of the event:

Photos of meteors detected during the day at the forestry centre using the radio and aerial above:

The following screenshot from Spectrum Lab shows the carrier from Graves (usually not seen but atmospheric conditions today meant it was intermittently visible) and two meteors (showing offset between meteors and the carrier of around 200Hz)

The screenshot below shows that the carrier is usually not seen. In addition, these meteors have spread on the frequency axis – indicating doppler shift in speed in components of the meteor (slightly different speeds of travel)

Other good examples of meteors on Spectrum Lab screenshots:

Meteors were also shown on WSJT-10 software waterfall traces – each time a meteor appeared on either WSJT-10 (below – the peaks on green trace + coloured spot above it – see for example second line on screenshot below where four meteors are shown) an audible ping could be heard from the laptop speakers.

Interpretation of above WSJT-10 screenshot:

Other good examples of WSJT-10 meteor detections (these would have simultaneously been seen on Spectrum Lab on 3D chart):

  

New Moxon aerial for meteor radio scatter

From: bill Watson [mailto:bill.g4eht@yahoo.co.uk]
Sent: 27 April 2017 17:31
To: Thornett Andrew (05Y) Walsall CCG
Subject:

 

HI ANDY

WE HAVE……………GOOD NEWS…….AND………BETTER NEWS. !

I HAVE TESTED THE 2 MTR MOXON…….IT IS FINE…..ABSOLUTELY NOTHING WRONG WITH IT……ITS BANG ON RESONANCE…..NO PROBLEMS. I TRIED MOUNTING IT VERTICALLY THOUGH………….NO CHANCE. !! HAVING THE POLE BETWEEN THE 2 ELEMENTS IS A……NONE STARTER. – SENDS IT WAY OFF RESONANCE, AND THE SWR GOES THROUGH THE ROOF. !

MOUNTING IT VERTICALLY WOULD MEAN USING A …NONE METALIC SUPPORT AT THE TOP SECTION…..AS I POINTED OUT. SO……I SET ABOUT MAKING YOU ANOTHER ONE ANDY. THIS ONE, I HAVE DESIGNED DIFFERENTLY……ITS MOUNTING POSITION IS DESIGNED TO FIT AT THE BACK OF THE REFLECTOR, AND NOT IN THE MIDDLE OF THE 2 ELEMENTS.

WHEN DESIGNING THEM LIKE THIS, YOU ALWAYS HAVE TO MAKE SURE THAT THE DISTANCE BETWEEN THE REFLECTOR AND THE MOUNTING POLE IS STILL NOT TOO CLOSE. !    A SIMILAR DISTANCE BETWEEN THE 2 ELEMENTS ID USUALLY SUFFICIENT….SO THATS HOW IT IS BUILT. I HAVE RESONATED IT AGAIN, SO THAT IT IS USABLE FOR 2 MTRS……IT CAN NOW BE USED EITHER VERTICAL/HORIZONTAL VERY EASILY WITHOUT BOTHERING ABOUT THE TOP POLE NOT BEING MADE OF METAL. I HAVE ALSO TREID USING IT FOR YOUR ‘METEOR RECEPTION’…….BRILLIANT. !

I MOUNTED IT VERTICAL FOR THIS TEST OF COURSE, HOWEVER I HAVE HAD ANOTHER THOUGHT. YOU PROBABLY HAVENT HEARD OF THIS ANDY – SLANT POLARIZATION. THIS MOXON, YOU CAN NOW EASILY…………SLANT POLARIZE…..IF YOU WISH. BY DOING THIS, IT’S POSSIBLE TO ( IF YOU LIKE ) GET THE ‘BEST OF BOTH WORLDS’. A BIT OF VERTICAL…………. A BIT OF HORIZONTAL………WHICH, IF YOU THINK ABOUT IT, MAY WELL E BETTER FOR YOUR METEOR DETECTION. FOOD FOR THOUGHT.?

ANYHOW……ITS UP TO YOU, TO USE IS IT, AND MOUNT IT AS YOU WISH. WHAT YOU MAY OF COURSE FIND, IS THAT AS YOU WILL NOW HAVE THE CAPABILITY OF EXTRA GAIN DUE TO IT BEING DIRECTIONAL  ( UNLIKE THE 5/8 VERTICAL )  AND BEING ABLE TO MOUNT IT VERTICAL AND BEAM SOUTH EAST, THEN IT COULD OUT PERFORM THE 5/8 WAVE. !!!!!!!!!!!!

HOWEVER…..IT WONT LOOK AS ‘NEAT’ AS THE 5/8  FOR YOUR XYL AND NEIGHBOURS. !

ANYHOW………ONCE AGAIN…ALL VERY WELL MADE AND SET UP, AND FOR CERTAIN IT WILL MAKE YOU A EXCELLENT PORTABLE AERIAL ANDY.

LET ME KNOW WHEN YOU CAN PICK IT UP, OR I CAN EASILY DROP IT OFF FOR YOU WHEN YOU ARE IN.

BYE FOR NOW

Vy 73……………..de……………….Bill…………..G4EHT

Further success recording meteors at LRO by radio scatter 22-23/4/2017 (Lyrid meteor shower)

The combination of our Yaesu FT-817 radio, high quality feeder cable and Bill Watson’s carefully hand-made 5/8 vertical aerial (made to be resonant at 149.049MHz) at 2.4m height (top of log cabin – neighbour politics mean I can’t have it higher) has led to great success detecting meteors by radio scatter during this Lyrid meteor shower – the best detection rates we have ever had in Lichfield. This demonstrates the importance of using a sensitive modern radio and a resonant aerial when detecting meteors.

I have also spent today trying to get FunCube Dongle Pro Plus working – without success!! I need help with this!

We proved that 143.049MHz Upper Side Band (on Yaesu appears as 143.049.00 R MHz USB) is a good frequency to detect meteors, the carrier for Graves appears intermittently and then goes again, when it does appear it varies up and down consistent with pulses from the radar, and that a resonant aerial is required.

Andy

Best screenshots from the Lyrid Meteor Shower 20-23/4/2017:

 

Following shows 2 typical meteor peaks but also shows Graves carrier which is usually not seen – meteor frequency is offset from the carrier.

2 meteors – these are probably 2 fragments of same meteor coming in one after the other:

Large rolling meteor – up and down with time as surface area increases and decreases with roll of meteor (below):

3 successive meteors:

                

Meteor below shows variation on frequency axis – this is due to multiple fragments together travelling at slightly different speeds – Doppler effect changes frequency:

Excellent example below of large rolling meteor:

     

Screenshots below show the 3D Spectrum Lab screenshot and also the WSJT-10 waterfall – this shows the ping that is seen and also heard if the computer’s speakers are turned on (audible ping not recorded here):

 

A possible reason for lower than expected numbers of Lyrid meteors detected before midnight by radio scatter from Graves last night

HI ANDY

JUST TO LET YOU KNOW FIRST OF ALL….

I AM SENDING THIS ON THE LAPTOP YOU AND RHYS KINDLY GAVE ME….I HAVE MANAGED TO GET IT TO TETHER TO MY FONE. IT IS EXCELLENT…….MANY THANKS TO YOU BOTH…

DEZ IS DOING HIS CONTEST…….BUT CONDITIONS ARE VERY DISTURBED AND THERE IS A GEO-MAGNETIC STORM THIS COULD WELL BE A FACTOR IN WHY THESE METEORS HAVE BEEN VERY SPARSE  TO BE DETECTED…..SO ANOTHER THING TO TAKE INTO ACCOUNT FOR FUTURE REFERENCE.

I WAS PLEASED TO SEE THAT PLANET THRU YOUR TELESCOPE. IT WAS REALLY GOOD TO BE ABLE TO SEE THOSE BELTS VISIBLE ACROSS IT……ALSO THOSE MOONS TO THE SIDE TOO.

THANKS AGAIN……………I WILL TRY THE ANALYZER ON THE 2 MTR MOXON……AND IF ITS OFF RESONANCE FOR ANY REASON I WILL ADJUST IT ACCORDINGLY.

BYE  FOR NOW

73…………..de,,……………..Bill………………G4EHT

Successful detection of many Lyrid meteors by radio scatter from Graves at LRO 20-21/4/2017

We are in the midst of the Lyrid meteor shower – and this has been demonstrated by my radio observing log over the last 1-2 days. The success of the new homebrew 5/8 aerial at LRO together with the Yaesu FT-817 radio led to the detection of 86 meteors between 20/4/17 @ 2246 – 21/4/17 @ 17:46. I have not had as much success trying to get the ICOM R7000 or FunCube Dongle Pro Plus working – the former might be a sensitivity issue or something more serious. As for the FunCube, I can’t seem to get the settings right to get it working with WSJT or Spectrum Lab but it does work with other software – so I am not sure what is going on there. Frustrating!

The reason for the high rate of meteor detection over the last 24 hours is that the Lyrid meteor shower takes place in the last week of April every year. In 2017 it is set to peak on the night of April 22nd and the morning of April 23rd, so we are already in its early stages.

21/4/2017 @ 18:08 Aerial feeder cable changed to one from log cabin that has previously used with R7000 (Remember one explanation for my failure previously to detect meteors may have been water ingress into this feeder cable at the aerial end). The gain as recorded by WSJT-10 software dropped by 3-4dB – I found that worrying. However, almost immediately, I detected a meteor @ 18:08 and another at 18:10 and another at 18:13 and a reasonable number of meateors have been detected since then up to 23:00 this evening so this drop seems not to be a major issue. Still, I would like to ask Bill’s advice on this.
One possible explanation for the failure of the previous aerial/radio to detect meteors is that water may have got into the cable at the aerial end. There is small amount feeder connected directly to this Moxon that then connects to the main feeder cable. The latter connection had been comprehensively covered with water-proof tape but not so the aerial end so water could have got in there and it may explain why my ability to detect meteors stopped reasonably suddenley last year. If this is the problem then the aerial no longer works but the main log cabin feeder cable will be fine (£50 worth high grade cable so it matters!)
19:00 Decided to try FunCube Dongle Pro Plus – unable to get settings right to put the USB Dongle through to WSJT and Spectrum Lab – don’t know why. I need to ask Peter Hill for advice as he uses it on his PC.

Andy

Examples of screenshots below showing meteor detections at LRO during Lyrid shower 20-21/4/2017 (note meteor shower continues over weekend and is expected to peak on Saturday night). The first ones are screenshots from Spectrum Lab software and those at the bottom of the screen from IrfanView software, which can record the whole screen and hence allow WSJT-10 waterfall to be simultaneously recorded with 3D view in Spectrum Lab.

Success moving aerial to top of log cabin

More success! I have now moved the 5/8 homebrew aerial to the top of the log cabin. Still using Bill’s feeder cable and the Yaesu FT-817 – and still detecting meteors at 143.049.00MHz USB. Can’t make up my mind yet whether number of meteors detected has gone now with move of aerial…..numbers have dropped since this morning but that could easily be due to variation in meteor rates anyway.

Andy

Bill Watson’s response to Andrew Thornett’s post on success of meteor detection at LRO 20/4/2017

HI ANDY

JUST READ YOUR COMMENTS RE-METEOR DETECTION…..YES, VERY GOOD AND THE PICCYS OF COURSE.

YES…..ONCE I HAD CARRIED OUT MY OWN OBSERVATIONS AND WAS CONFIDENT THAT VERTICAL POLARIZATION WAS THE BEST I THEN DECIDED THAT WITHOUT DOUBT THE BEST VERTICAL AERIAL HAD TO BE CONSTRUCTED!

THE 5/8 IS THE BEST PERFORMER DUE TO ITS ‘LOW ANGLE OF RADIATION’ AND OF COURSE, AS ‘GRAVES’ IS SO FAR AWAY FROM LICHFIELD FOR VHF THAT WAS OF VITAL IMPORTANCE. THE PROBLEM WAS…….CONSTRUCTION. ! THEY ARE FAIRLY DIFFICULT TO MAKE DUE TO THE FACT THAT A PROPER IMPEDANCE MATCHING NETWORK NEEDS TO BE MADE AT THE BASE TO ALLOW 50 OHM IMPEDANCE FEED TO BE CONNECTED……NOT ONLY THAT BUT ALSO A PROPER ‘RADIAL SYSTEM’ NEEDS TO BE FITTED AS WELL. THIS WAS ACHIEVED, BOTH THE MATCHING COIL  AND RADIALS AFTER QUITE A BIT OF TRIAL/ERROR  TESTING…..USING THE ‘MFJ ANALYZER’ WHICH IS A …..MUST HAVE TOOL. THE OUTCOME……RESONANT ON……143.049…….IMPEDANCE…….50 OHM.

…………….NOW…ON TO RECEIVING QRG…TESTED TODAY

…………… DURING HIGH LEVEL OF ‘MS’ ACTIVITY.

OPTIMUM QRG……………………………………………………..143.049 Mhz……… ( usb )

TESTED QRG WHERE ‘MS’ ALSO RESOLVED……………..143.049.50 Mhz

TESTED QRG WHERE ‘MS’ ALSO RESOLVED……………..143.048.50 Mhz

PLEASE NOTE……………………..AT NO OTHER QRG WAS THERE ANY ‘MS’ ACTIVITY.

WHAT SURPRISES ME ANDY IS THIS…..THE BOOKS SAY…….143.050 Mhz……….IF YOU HAD TOLD ME THAT QRG FROM DAY ONE, WHEN YOU ASKED ME AT CHURCH A COUPLE OF YEARS AGO THEN I WOULDN’T HAVE RECEIVED A DICKY BIRD. I WOULD HAVE JUST THOUGHT…….NO……NO CHANCE….IT DONT WORK. ! SO, IT WAS FORTUNATE THAT YOU DIDNT TELL ME WHAT THE BOOK SAYS AT….. 143.050 Mhz…………..OTHERWISE YOU’D STILL BE TRYING. !

I WILL LOOK FORWARD TO SEEING YOU ON SATURDAY EVENING AFTER 9 PM

73…………..de,,,,,,,,,,,,,Bill………..G4EHT