Radio Astronomy

August Meteors

Although not visually very active (clouds again!!) the Perseids were very prominent in the  radar data. In my post mid august the data showed a maximum daily rate of 313 on the 13th with a maximum hourly rate of 28 between 2-3am on 12th, and as the hourly plot showed the main activity was between 2 – 8 am hence missed by lots of people even if clear, Ed and Dave at Solarfest went to bed too early!!

The meteor count total for the month was 2999, with an average daily count of 97 and average hourly rate of 4.

The hourly and daily plots are below and for comparison below these  the August  daily count for the last 3 years, interestingly the shower peaked on the 13th in 2018, 2017 but on 12th in 2016, this however is only the daily count and a different set of conditional actions for recording events is now in use.

The final chart is a reposting of the 2018 shower data.

Perseid Shower 2018

The Perseids have been and gone, maximum hourly count was 28 between 2-3 pm on the 12th and the max daily count was 313 on the 13th. The hourly plot between 10th and 16th shows the daily shower distribution quite clearly, maximum activity picking up for 2pm onwards on most days , hence not many being seen, also the majority of counts were of low duration, so most not very bright, there were some longer duration signals associated with fireballs but not many and certainly not bright enough to trigger the all sky camera which I had running when sky was clear.( which wasn’t very often)

Perseids-ish – Apologies photos now added!

First an apology – for some reason the system wouldn’t let me upload any pictures, I thought I just gave up, but it’s published the post anyway!

My weekend went a bit pear-shaped so I ended up trying to get some Perseid images last night. I only saw one, and my very last shot of the night picked up a very faint one heading straight from the radiant near the double cluster, please excuse the awful coma, on 10th.

Persied 2018
Persied 2018

This appears to be an ion trail from a meteor that sneaked through between shorter exposures on the 14th

Having much more luck with the Graves Radar setup, thanks to Peter hill for his inspirational talk which encouraged me to take the plunge!

I ahven’t been as sophisticated in my counting of events – my brain isn’t up to checking several thousand screen gabs, so yes there are multiple counts in there as well missed counts from meteors arriving before the previous one finished, space debris and the ISS on multiple occasions.  My assumption is that all these errors are effectively random and don’t affect the overall profile significantly.

These are my hourly counts, all peaking about 6:00am – UTC/GMT.

This is the average of the above graph, easier to see the overall daily pattern:

And all the data in a row, to show how the peaks rise and fall:


All data as a single series
All data as a single series


And an example of some detections:


The Perseids are coming!

Monitoring of meteor activity using the reflection of the Graves radar signal with the fundongle pro+ shows a gradual increase in the daily count since start of month ( 78),  up to 109 for yesterday and the maximum hourly rate has now risen to 15, also noticeable is the higher frequency of longer duration events, that could indicate fireballs such as this trace below. The peak is due on the eve of 12/13 Aug but also possible to view on 11/12th , however forecast is not good for either night !! However with the increase in activity and higher incidence of long lasting trails it might be worth having a look on the eve 10/11th as at least it is supposed to be clear!

July Meteors.

Although the July radiants do not individually produce strong rates, activity from the Aquarius and Capricornus regions in July and early August, as well as minor activity from other radiants, cause hourly rates to basically rise between the middle and end of July for observers in both the Northern and Southern Hemispheres.” (

Moderate Activity:

Radiant Duration Maximum
Southern Delta Aquarids (SDA) July 14-August 18 July 28/29

Minor Activity

Radiant Duration Maximum
Alpha Lyrids July 9-20 Jul. 14/15
July Phoenicids (PHE) July 9-17 Jul. 14/15
Alpha Pisces Australids July 16-August 13 Jul. 30/31
Sigma Capricornids June 18-July 30 Jul. 10-20
Tau Capricornids June 2?-July 29 Jul. 12/13
Omicron Draconids July 6-28 Jul. 17/18

The total number of meteors detected in July (2018) was 1824, with a mean daily rate of 59 and mean hourly rate of 2.5.

The maximum daily rate was 87 on the 26th July and the maximum hourly rate was 11, between 3-4am on the 27th and 30th.

The daily and hourly rates are shown in the first two charts below

These maxima coincide with the SDA shower and the trends over the month reflect the observation quoted at the start of this post. The trend of increasing activity towards the end of the month is borne out in the last chart below which compares the data over the last three years, the suggested trend is more pronounced in the 2016 and 2017 data than this year .

The Perseids are already with us peaking on the night of the 12/13th August, and with a new / very young moon there should be good viewing conditions as long as the clouds stay away.

Nightwatch event 27/7/2018 & successful detection of start of Perseid meteor shower at Rosliston Forestry Centre

On paper, the Nightwatch event was going to be particularly amazing this year. This annual event is an outreach activity organised by Rosliston Forestry Centre, where the astronomy group always has a presence. Many members of the public come to look through our telescopes, watch owl and bird or prey displays, go on a bat walk and join the moth group to explore the world of moths.

Last night stool out in that it coincided with the date of one of our usual meetings, and at the start there was going to be a total lunar eclipse and many planets were on display.

In addition, the sky had been amazingly clear for weeks beforehand.

…….Until the day when it clouded over and we could not see a thing in the night sky during the event!

Good job I bought my mobile meteor radio kit along (telescope at the ready to go in car at home – replaced last minute when I looked at the sky) – worked well (thanks to Bob Williams in particular for his help here) – plenty of meteors detected – we are the start of the Perseid meteor show with the keep coming up in a couple of weeks. The kit includes small portable aerial, Yaesu FT-817 radio, audio cable connection to my windows laptop, Spectrum Lab software, all powered very successfully by Ed Mann’s power pack – the inclusion of in-built inverter and 240V sockets on the side is a real boon. The radio is 12V and currently I am running it through a power supply that plugs into 240V socket which is a bit ridiculous – must make a 12V socket version.

Nevertheless, quite a few people turned up from the club to meet members of the public. Plenty of scopes were on display. It stayed dry and we all had great fun.

This is what it means to observe in the UK. You’ve got to be interested in clouds.

Particular thanks are due to Damian who made the effort to attend in spite of needing to get up really early the following morning to catch the plane for his holiday.

Look at how dry the grass is! We have had a particularly dry summer this year.



Meteor detection screenshots from Spectrum Lab:

June Meteors

No major activity in June , the June Lyrids the most active around the 15th/16th of June, the peak is distinguishable on the daily count plot. The peak activity around the 10/11th, is probably the combination of the Theta Opiuchids and Saggitariids.  The rest of activity during the month a combination of the many minor showers present.

The dip in the daily rate on the 6th is due to Graves being off line between 01-05 hrs. The activity has dropped of to about 50 meteors / day towards end of month and has continued at this rate into July which is a relatively “quiet” month.

The plot is similar to the daily plot from 2017, although rates lower( this is probably dependent upon the density of the debris field the earth passes through )

I’ve listed the showers for June below as are the daily and hourly plots for June 2018 and the daily plot for June 2017.

Moderate Activity:

Radiant Duration Maximum
June Lyrids June 10-21 Jun. 15/16

Minor Activity:

Radiant Duration Maximum
June Aquilids June 2-July 2 Jun. 16/17
June Boötids June 27-July 5 Jun. 28/29
Corvids June 25-July 3 Jun. 27/28
Tau Herculids May 19-June 19 Jun. 9/10
Ophiuchids May 19-July 2 Jun. 20/21
Theta Ophiuchids May 21-June 16 Jun. 10/11
Sagittariids June 10-16 Jun. 10/11
Phi Sagittariids June 1-July 15 Jun. 18/19
Chi Scorpiids May 6-July 2 May 28-Jun. 5
Omega Scorpiids May 19-July 11 Jun. 3-6
June Scutids June 2-July 29 Jun. 27/28

Daylight Activity

Radiant Duration Maximum
Arietids May 22-July 2 Jun. 7/8
Zeta Perseids May 20-July 5 Jun. 13/14
Beta Taurids June 5-July 18 Jun. 29/30

May Meteors.( Based on Graves Radar)

The main meteor shower in May is the Eta Aquarids,  it is however not the only shower and there are several daylight showers as well. The effect of this is for the “peak” of activity not to be situated around the 5th / 6th of June but elsewhere. This can be clearly seen on the daily and hourly plots for the month both for this year and last year.

Major Activity:

Radiant Duration Maximum
Eta Aquarids (ETA) April 21-May 12 May 5/6

Minor Activity

Radiant Duration Maximum
Epsilon Aquilids May 4-27 May17/18
May Librids May 1-9 May 6/7
Eta Lyrids May 3-12 May 8-10
Northern May Ophiuchids April 8-June 16 May 18/19
Southern May Ophiuchids April 21-June 4 May 13-18


Daylight Activity

Radiant Duration Maximum
Epsilon Arietids April 25-May 27 May 9/10
May Arietids May 4-June 6 May 16/17
Omicron Cetids May 7-June 9 May 14-25
May Piscids May 4-27 May 12/13

Successful detection of meteor shower by radio scatter at Damian’s house Streethay from Graves’ radar

After Peter Hill’s brilliant talk at the last RAG meeting, we were both motivated to pull out Andy’s radio meteor kit and give it a try. In the past Andy has had real problems getting it working at his house and we don’t know why. First step was to try it elsewhere – Damian volunteered his house for the task today.

A useful day of testing Andy’s portable meteor detecting equipment…

Picture contributions from Andy, Damian and Julie (+ annotations!)

Setting up at Damian’s house…

Dancing around the Maypole!

Getting there…

Done…. and ready to go!

Andy bought along a selection of aerials – in the end he chose the simplest and cheapest off the shelf one rather than the hand-made and carefully cut (length to frequency by Bill from Lichfield) versions below….

Our chairman with his radio equipment at Damian’s house (below):

Peter used his FunCube Dongle for his detections. To simplify this initial trial, Andy bought along for this test his Yaesu FT817 portable radio. We used Peter’s settings file and a cheap off the shelf aerial and cable and a car battery to power everything.

The aerial poles are an ex-military carbon fibre Clansman kit – 5.4m high! Andy initially bought these several years ago to use with his Radio Jove Jupiter radio-observing radio and aerials but they are also very useful for meteor detection!

Clansman aerial mast kit:

Immediate success with the military aerial at full height !

Screenshots from Spectrum Lab showing meteors in Damian’s garden:

Success was at the Graves’ frequency 143.049 MHz (Upper side band):

We then tried reducing the height of the aerial to roughly the same height as the aerial on the roof of my shed (2.4m) where my current aerial is located.

We found we were still able to detect aerials roughly every minute or so. Their peak magnitude did not seem to be as large as when the aerial was twice as high………so reduced height = less meteors and reduced magnitude of detection.

Next step was to take the set-up which we had just proved worked back to Andy’s house to see if it worked in his garden to test the theory that he lives in a radio black spot which explains his difficulties over so many years.

The following are screenshots from Spectrum Lab in Andy’s garden showing meteors:

Next steps for testing Andy’s meteor observing problems in his garden:

1. Test the same kit as above with different heights of aerial.

2. Erect aerial above and record meteors over 24 hours.

3. Try recording meteors with lower height aerial in Andy’s garden during meteor shower – no meteor shower major or minor today in standard lists.

4. Use aerial on top of shed with Yaesu radio to see whether meteors are detected.

5. If yes to 4 then try changing radio to FunCube Dongle to see if still works.

6. Try kit as above in Andy’s and Damian’s garden but this time using FunCube Dongle rather than Yaesu radio.

For future reference, we came up with this list of equipment we need to take with us on future radio meteor observing sessions, out of the home location (such as outreach sessions at the forestry centre):

  • Yaesu FT-817 radio – make sure power cable, audio cable in the box.
  • Laptop with spectrum lab and settings files.
  • Computer hood or box so can see screen in sun
  • Portable table and chairs or stools
  • Car battery
  • Inverter
  • Multiple plug adapter so can plus both laptop and radio into the inverter (at least two plugs)
  • 12V power supply for radio – alternatively 12V battery
  • Mallet to hammer in pegs for aerial
  • The C-Clamp on the aerial is larger than the Clansman aerial poles so need piece of wood to go in between C-Clamp and aerial.
  • Clansman aerial poles kit in green bag – make sure 6 poles, 2 x round discs for attaching the guide ropes, 3 x metal strips wrapped with guide ropes x2 per strip, 5 x pegs.
  • Extension cable for aerial (may not be needed depending on aerial used).
  • Aerial – today we used off the shelf Yagi for UHF – cheap and cheerful but effective! If this one is used then extension cable not required as it has long cable with it.

We then returned to Andy’s house to try the same set-up at his… plus a beer!

Damian and Andy