Science – Page 7 – Fooyah

April 9 2019April 9 2019

Mutability

A few summers ago my project was to build an ADS-B receiver and use the data collected to upload to an aircraft tracking website. If you want to see what I see then go to:

360 Radar

I don’t remember the details about how I found this but the project was good fun and I got the Raspberry Pi in the loft with a decent aerial, filter and pre-amp, and it was all working fine. I was using a lovely piece of software called Virtual Radar Server and was able to use this as a web server and people could see the aircraft on web pages served by the Pi.

360 Radar is good because it using multi-lateration to detect the positions on military aircraft. This is pretty handy for spotters like me and it also works well when I take cadets to RAF Wittering for some Air Experience Flying, I can see where my cadets are in the air.

Over the last few months I’d been receiving outage warnings from the 360 guys. It would appear that my Pi had stopped sending them data and while I live in a flight-busy area of the country and there’s plenty of contributors here every little helps. I had the occasional outage and this seemed to be when the router reset and the Pi wouldn’t re-find the existing wi-fi network. I just had to power cycle the Pi and everything worked fine. The outages seemed to be occurring more over the last while with the Pi stopping feeding every few days.

At first I thought it was a wi-fi issue so I bought some new ethernet-over-power adapters and linked the system into the route via a wired connection. This also meant I could ssh in to the Pi even if wifi was the original problem. I tried to work out how to turn the wifi connection off entirely but just ended up changing the SSID the Pi looked for as a simle way of ensuring the wired connection took preference.

After a week of testing I was still getting outages and my initial thought was that the VRS software was making the Pi work too much. I’m not sure why I thought that but I looked up ways to remove VRS. This was not the easiest as I had installed it years ago and couldn’t remember how it ran within the OS. I eventually managed to remove the Mono service and this stopped VRS running.

It was at this point I worked out how to use the log file of the MLAT client and I could see that all the software seemed to be working fine it was the Dump1090 program that didn’t seem to be sending data internally. I figured that Dump1090 had somehow stopped receiving the signal from the aerial. It all worked fine after a reboot and so I decided to replace the USB dongle that was decoding the ADS-B signals. I ordered a FlightAware USB stick and at the same time decided I would rebuild the Pi OS from scratch to have a “clean” build.

Once the new USB stick arrived I turned off all the systems and followed the excellent instructions from the 360 Radar guys to rebuild the OS of the Pi and just run a lite version of what I had been doing before. This took a while as I mistakenly thought the Pi wasn’t uploading to 360 because I was looking at the wrong server details. After an email to the support chaps it turned out I was contributing and a couple of hours of troubleshooting by me hadn’t been worth it!

So, the Pi sits in the loft, chugging away supplying data to 360 Radar, in return for which I get free access to their excellent tracking site. I’m running dump1090-mutability along with the MLAT-Client from 360. I’d really like to be able to allow you all to see the output of this but Mutability doesn’t have an external feed and I am not opening up my 80 port for the world.

March 17 2019March 17 2019

BAH!

Yesterday I went to Imperial College to see two talk / roadshow things. The first was the Ig Nobel roadshow which lasted about two hours and had talks from the chap who runs the Ig Nobel awards and also from four scientists who had won the prize. The Ig Nobels are awarded for science that:

makes you laugh, then makes you think

It was a lovely couple of hours hearing about the endeavours of scientists from around the world trying to make the world a better place.

I laughed and smirked and reveled in the atmosphere of nerdery and geekiness. You can watch it below:

After an intermission of a couple of hours there was the London round of BAHFest. The Bad Ad-hoc Hypothesis Festival. I went last year and enjoyed it immensely. I really liked it again this time around. The ideas were delightful and thoroughly entertaining. Watch it now:

Hopefully my calendar will allow me to go next year. Such a delightful event.

February 23 2019February 23 2019

Goodbye Tonkas

As part of my trip around Lincolnshire I spent a few hours outside Coningsby watching the Typhoons. They are pretty loud when taking off although one did set my car alarm off by doing a full-afterburner take off and heading straight up to 15,000 feet.

I also went to the BBMF hangar and looked around the various types they have there. Here’s their Lancaster:

I also saw another Lancaster at ex RAF East Kirkby.

Just Jane - Avro Lancaster — Just Jane – Avro Lancaster

However, the main reason for being a hundred and sixty miles from home was to be relatively close to RAF Marham so I could try and see some Tornados flying before they end their airborne days. I had noticed there was a NOTAM out for Marham on the Friday and so I planned to be there about half an hour before the start of whatever it was. I figured that if it wasn’t the Tornados it would be a Lightning II and that wouldn’t be such a bad thing to see. I still haven’t seen one fly and I could only just make out two in real life over the other side of the airfield.

I was lucky. There were five Tornados going up and preparing for a final display and fly past later in the month. It was really good to see them taxiing.

Tonka Formation - RAF Marham — Tonka Formation – RAF Marham

After about an hour over the North Sea doing their stuff they headed back to Marham but not before I had seen four F15s fly over and then three KC-135s in formation. They were a sight to see!

So I have two Tornado stories for you. The first was at North Weald airshow in the late 80s. My friend Nick and I had cycled from home and couldn’t afford entry so we just parked our bikes inside one of two fences in line with the end of the runway. We figured we weren’t airside and neither were we next to the road, we were in a kind of no-mans land. A Tornado lined up in front of us and then used full re-heat to take off. The noise and vibration was amazing. It was an awesome sight.

My next anecdote involves me being a cadet at RAF Coningsby in 1988. I was allowed to sit in the cockpit of a Tornado ADV and I played with the throttle. I was later told that doing this had dumped some fuel in the engine, but I wasn’t concerned. Later that night I was on the flight line “helping” and the aircraft I had been sitting in refused to start. It looks like I broke it [a little].

Head On - Panavia Tornado — Head On – Panavia Tornado

While at Marham the spotters got our own little airshow and it was such a delight. It was a special time to see these aircraft doing what they were meant to do, which is fly, for the last time.

I should add in that while in Cyprus on cadet camp there were Typhoons and Tornados taking off every evening to bomb ISIS in Syria and Iraq and I remember watching them leave while we were at the beach bar on Akrotiri. The after burners, the noise and the sight was spectacular. Tornados going to do the job they were designed for.

January 12 2019January 12 2019

Midnight

I’ve been thinking about time. Well, let’s face it I think about lots of things all the time but time is problematic. I was mostly thinking about this at the turn of the year, when 2018 magically turned into 2019 or the start of the nth journey around the sun when starting from an arbitrary point. I mean starting the new year on the day after the shortest day for the northern hemisphere would be more sensible but I guess we could have a war with the southern hemisphere about that.

Midnight is the first moment of the next day. When the clock hits 00:00 that is the start of the next day. The previous day ends at a moment which is the limit of all time before 00:00. Twelve AM is the beginning of that day. Such is the definition.

Now, here’s the problem and it involves language and colloquialisms as is often the case with problems about definitions. Within mathematics there are plenty of words which have specific definitions in the subject and different meanings in casual language, I mean that was designed that way originally to exclude the masses from education.

So, if I said to you I will meet you “at midnight on Thursday” then it is likely that we would be talking about meeting at the boundary between Thursday and Friday. But, if I said I’d meet you at 12am on Thursday that would probably mean we were still meeting at the boundary between Thursday and Friday but in reality that time is the boundary between Wednesday and Thursday.

Thinking about this now I think it would be only me having problems with a meeting time of “midnight on Thursday” and in a group discussion I would be the one asking for clarification whereas everyone else would be perfectly happy with the understanding of the meeting time. Oh how I hate language sometimes.

October 25 2018October 25 2018

Not Really

This one is easy pickings really. Almost everything written in the Daily Express is rubbish and it has been amongst the leaders of our “free press” stoking the embers of racism and nationalism over the last few years. But, let’s stick with science:

I took this clip of the Daily Express two days ago. It’s a photo that was shared widely through the press and you’ve probably seen it.

It is a good photograph and quite stunning. Although we can’t see the right hand corner of the iceberg and I couldn’t see any other views of this iceberg so I wonder how rectangular it is and how many people’s brains will fill in another right angle.

I’m more interested in the words that the Express uses.

“Nature can do straight lines” – yep, knew that already. Pretty sure light travels in straight lines (at a basic level). Also, notice that the edges of the ice berg aren’t straight. There are bumps and lumps. So, it’s not straight. It just appears that way.

“Eerily perfect 90-degree angles” – hmm, have they measured that? Perfect 90-degrees is pushing it a bit. I mean they can be close to 90 but “perfect”. Bullshit. In the very NEXT paragraph they say the angles can be “about 90-degrees”. So they dismiss their own claim in the VERY NEXT PARAGRAPH.

“Perfect ice rectangle” – but it’s not perfect. What sort of person writes that word in a news article? We can’t see the rest of it. The picture is at an oblique angle so we can’t measure the sides. I doubt the Express have done anything like that.

So, let’s see what NASA said about their photographs:

“I was actually more interested in capturing the A68 iceberg that we were about to fly over, but I thought this rectangular iceberg was visually interesting and fairly photogenic, so on a lark, I just took a couple photos,” Harbeck said.

The photographer took the photos for a lark! Brilliant.

They aren’t all that rectangular:

In fact pretty much all of them are irregular in shape and so the odd one that looks a little special to human brains isn’t that exciting:

How do you get your kit to Antarctica? In a large plane of course. How do you land large plane? Make an ice runway:

October 13 2018October 13 2018

Glorious Colours

Here are a couple of photographs taken of the glorious colours in the morning skies above Kent.

I know they are sunrise because both of these photos have the camera facing to the East.

The weather for the last few weeks has not been usual. We are in the middle of October and I’ve only had the heating on for two days and that was me being luxurious.

September 11 2018September 11 2018

Disconnected?

The speedometer in my car over-reads. The car, named Bora Horza Gobuchul, has been with me for a while and I remember being on a motorway thinking that I’ll settle at 60m.p.h. as I wasn’t in a rush. After a while I was being overtaken by HGVs and that was quite disturbing given they have a 58m.p.h. speed limit. So, I got a speed application downloaded from the iTunes store and tested my speed using the phones GPS signal.

The result, my speed, according to my phone, was 54m.p.h.

That explained a lot. I had never tested the speedo in the Beast, there never really seemed to be a need to do it. So I set about testing the readings my car was giving me and it turns out that my speedometer over-reads my speed by 10%.

So, if the car is indicating 70m.p.h. then I’m really going 63/64 m.p.h.

My understanding is that speedometers are allowed, legally, to over-read the speed but NEVER under-read the speed. Because of this rule that they are NOT permitted to under-read means that a tolerance HAS to be included for under-reading. It would be costly for manufacturers to produce speedometers that are “exact”.

So, a car indicating a speed of 70m.p.h. could be doing anything in the range of 63 to 70 m.p.h.

Having tested this and observed the traffic around me and used various different speed testing apps I have now adjusted my speed accordingly. This effect could also be deliberate to try and make Prius drivers drive a little slower and therefore save fuel. You use approximately twice the fuel to travel at 70 than you would at 50m.p.h.

Now, here’s the rub:

My car has a “computer” as they used to be called and it tells me average speed, m.p.g. etc. Over the summer I reset this to zero while travelling on a clear motorway. I set the car’s cruise control to a steady speed of 77m.p.h. and reset the trip computer. Once the computer had enough data it flashed up my average speed: 70m.p.h! This continued over the next ten miles of travel before I had to slow down.

It appears that the car’s trip computer reads or reports the correct speed.

This confuses me. The trip computer either uses a different source for its data OR it knows the correct speed from the existing source. I don’t understand why either of these would be designed like that. The car has a mechanical device for reading the speed OR it could use the GPS system but why over complicate things?

I don’t understand my car.

September 3 2018September 3 2018

Practise Refuelling

I’ve written here quite a bit about ADS-B and stuff along with tracking aircraft and multi-lateration. Well, I was looking at the aircraft tracking website 360 Radar this evening and spotted an amusing thing.

The route shown on the picture is that taken by an RAF Voyager aircraft over the North Sea. The plane took off from RAF Brize Norton and headed out over the Scottish area of the North Sea. The green area is rain and the purple highlights are RAF airfields along with the blue highlights showing civilian airports. What particularly struck me about this picture was the almost-penis drawn as the second area of activity. I think they should have tried a little harder [but would probably get “moved” assignment].

Let’s put this thing into some perspective by adding recognised Danger Areas in red and refuelling training areas in green.

Now we can see that the Voyager has maneuvered beautifully through the danger areas and maintained some lovely flight paths in the AAR areas. The plane is currently at 16,000ft and moving at 330 kts. Pretty standard stuff.

It’s amazing to see that this is practiced and practiced to make sure that when it comes to doing this in a real theatre everyone knows exactly what they are doing and it all goes to plan.