* Posts by Richard Simpson

14 posts • joined 8 May 2007

UK authorities probe 'drone hitting plane at Heathrow'

Richard Simpson

Re: Detection would be a good start

Firstly, most modern systems don't use triangulation, but time difference of arrival, as I think I mentioned.

I agree that you may need quite a few stations to track signals on the ground depending on how large an area you want to cover, but for tracking the actual drones the problem is a lot easier since we are only interested in the skies on the approach and departure flight path. Clearly, we can construct antennas that point in that direction and ignore most of the interfering signals that don't interest us.

I am not convinced by your interference argument. Consider the drone. It is clearly flying at a reasonable altitude in order to strike an approaching aircraft. If it can distinguish its own control transmitter from the hundreds of other 2.4GHz sources visible from the air then so, presumably, can our tracking system.

I don't believe that there are any mobile phone frequency bands around 2.4GHz and your complaint seems to be based on the rather quaint idea that mobile phone locations aren't already tracked. As for Bluetooth, this does sound like it would be too low power to be usefully tracked.

So, in summary I don't agree that this is not a bright idea.

In related news, a colleague has pointed out to me the following system which seems to take the special to purpose radar approach: http://www.blighter.com/products/blighter-auds-anti-uav-defence-system.html

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Richard Simpson

Re: Detection would be a good start

Agreed. I should of course have written "developed".

The thing with writing long comments at work is that time for reflection and review is rather limited!

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Richard Simpson

Detection would be a good start

Clearly, in addition to serious jail time for anyone doing this (what's the betting that even if caught they'll get a short suspended sentence) we clearly need better schemes for detecting drones in prohibited areas. And yes, this sort of thing is in my line of work.

Idea 1) Already mentioned by others is the idea of triangulating the locations of transmitters. For locating the drone (and thus warning pilots) this is probably not too difficult. Technology like VERA (https://en.wikipedia.org/wiki/VERA_passive_sensor) which relies on time difference of arrival could do this easily. A much simpler system than VERA would work fine since the range needed is limited and only a few frequencies need to be covered. Detecting the ground transmitters is a bit more challenging since the RF path is more obscured and of course you will get a lot of false positives but I thnk that a system, perhaps installed on current mobile phone masts would be possible. Of course, in both cases radio silence could be adopted with the drone operating automatically, but people who do this are by definition morons and therefore usually not clever enough to work that out.

Idea 2) Dedicated radar - Presumably, these drones are not currently showing up on airfield radars because (a) their radar cross section is too small and (b) their speed is too low and therefore the radar's Doppler filter removes them as clutter. But, in my professional opinion a suitable radar could be invented. It only needs to search a limited amount of space where aircraft are taking off and landing and it could use the no doubt very distinctive Doppler shift from the props as a discriminant so it doesn't keep detecting birds (like the counter helicopter mode on some military radars),

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Saturn spacecraft immune to mysterious Planet 9's charms

Richard Simpson

It's Saturn's orbit which is at question

I may not have understood correctly, but when I read the paper about Planet 9 and Cassini it seemed to say:

1) That perturbations in the orbits of the planets limited the possible locations where Planet 9 could be in its orbit (even assuming that it exists).

2) That the orbital models being used relied on the motion of all the planets and numerous asteroids going back several decades.

3) That slight changes in the orbit of Saturn were a particularly relevant part of the data set and that Cassini was simply a handy way (via radio ranging) of finding out exactly where Saturn was.

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Hands on with the BBC's Micro:Bit computer. You know, for kids

Richard Simpson

Old photo caption

The caption to the photo at the bottom doesn't seem quite right. The computer in the picture looks to me like an Acorn Atom. Was this Acorn's first 'kids' computer? Well, maybe. I was a kid and I certainly had one (and spent hours explaining to my ZX81 owning school friends that a real keyboard was actually rather important).

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No more Nookie for Blighty as Barnes & Noble pulls out

Richard Simpson

Re: March with your wallet - buy only open formats

Most MP3 patents have expired and the few that remain will do so by the end of 2017.

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Bruce Schneier: We're sleepwalking towards digital disaster and are too dumb to stop

Richard Simpson

Re: It's gonna be difficult...

Can you explain exactly where you saw the regulation about reducing the power of kettles. An actual link would be useful. Last time (it was about a year ago) there was an EU study into proposed energy saving measures I took the trouble to look at the bit about kettles. It proposed two solutions:

1) Better insulation.

2) Far more effective 'auto switch off when it boils' mechanism that work promptly when the kettle is new and don't get steadily less effective as it ages.

Both struck me as being quite sensible. Of course, you are going to ask me for a link to the study I am referencing and that could take a while to find.

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Ukraine has a Eurovision pop at Russia

Richard Simpson

Re: Rules is rules

Whilst I agree that there is a considerable amount of politically driven voting, I have yet to be convinced that it has a big effect on the answer. The last ten contests have been won by nine different countries (Sweden won twice) although with also one win each for Finland, Norway and Denmark it does appear that Scandinavia does rather well, but OTOH none of the Scandinavian countries have been runner up in the last ten years and if they had an advantage you would expect them to do well in second place as well.

Also, if it was true that there is a big dislike for Russia throughout Europe, they wouldn't have won once and come second three times in this period.

I find myself of the view that the effect of political voting isn't enough to produce a serious distortion in the results and this has been helped in recent years by the semi-finals. After all, if your political buddies don't get through to the final then you can't vote for them and have to give your douze points to someone else.

One final thought. There are about 40 entrant counties each year, so if the mechanism was completely fair the UK would expect to win once in every 40 years!

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Richard Simpson

Rules is rules

If Eurovision has rules forbidding songs with an overt political agenda then is should enforce them equally on all contesting nations irrespective of how popular or otherwise the political agenda in question is.

The resulting contest will, as always, consist entirely of bland drivel, but surely that is what Eurovision viewers want and expect.

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Finding security bugs on the road to creating a verifiably secure TLS lib

Richard Simpson

Re: Mathematically correct code

Is this an issue in this case? Surely TLS execution time isn't a limiting factor in most internet transactions? Even if it ran at a fraction of the current speed, would that be a problem for most modern computers? Hmm, perhaps an issue at the server end. Presumably this scheme can't be extended into hardware crypto accelerators?

Also, forgive my ignorance, but I thought that TLS was primarily used to achieve a secure key exchange for a traditional cipher which is then used to exchange the actual data. I get the impressions that this work isn't fiddling with the actual cipher code which will remain just as fast and/or buggy as now but I am ready to be corrected on this point.

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Indie review of UK surveillance laws: As you were, GCHQ

Richard Simpson

Relatively good on Encryption

Having waded through quite a bit of the report, three paragraphs in particular seem pertinent to the encryption debate:

13.11 ...There may be all sorts of reasons – not least, secure encryption – why it is not physically possible to intercept a particular communication, or track a particular individual. But the power to do so needs to exist, even if it is only usable in cases where skill or trickery can provide a way around the obstacle. ...

13.12 ... Few now contend for a master key to all communications held by the state, for a requirement to hold data locally in unencrypted form, or for a guaranteed facility to insert back doors into any telecommunications system. Such tools threaten the integrity of our communications and of the internet itself. Far preferable, on any view, is a law-based system in which encryption keys are handed over (by service providers or by the users themselves) only after properly authorised requests.

13.13 ...there is a compelling public interest in being able to penetrate any channel of communication, however partially or sporadically. ... Hence the argument for permitting ingenious or intrusive techniques (such as bulk data analysis or Computer Network Exploitation) which may go some way towards enabling otherwise insuperable obstacles to be circumvented

So, he seems to be saying that encryption should not be legislated against (as now), laws should exist to force people to hand over keys (as now, but step forward perfect forward secrecy) and GCHQ should be allowed to try to break encryption (again, presumably as now).

Laws forcing password hand over remain troubling, particularly for those of us getting older and more forgetful, but they have two big flaws from GCHQ's point of view; (a) they are expensive to apply so can't be done on a massive scale and (b) the suspect then knows for certain that they are being investigated. Otherwise, it remains that case that we can try to make our systems more secure and GCHQ can expend effort and money trying to break in - Game On!

Of course, this is all just a report with no legal powers from a lawyer who can be replaced if he starts saying too many sensible things. It remains to be seen if May and Cameron take any notice of it!

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Japan scores ballistic missile shootdown bullseye

Richard Simpson

ICBMs fly too high?

Hmm, perhaps I am missing something here, but surely ICBMs only fly high for part of their journey. Surely, they have to come down to lower altitudes at the end of their flight, otherwise, they won't do anything useful? Now, I don't doubt that shooting down ICBMs is more difficult, but perhaps it is because they go faster? After all, if they go higher up and they had a bigger rocket to start with then it seems logical that they will be going faster by the time they get near the ground.

This all reminds me of an article by George Orwell in which he mocks pre-WW2 newspaper articles explaining that there is no threat from German bombers because anti-aircraft defences would force them to fly too high. The idea presumably being that if you drop a bomb from high enough then it won't reach the ground :-)

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Patent damages not refunded if EPO cancels patent

Richard Simpson

Just a statement of what we all know anyway.

So far as I can see, all the judge is saying is that it is OK for the legal system to be unjust, so long as that is good for business.

Surely it has been painfully obvious for years that this is their opinion, its just that judges and politicians don't normally come right out and say so.

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Student detained following attacks on Estonian websites

Richard Simpson

Some interesting points

1) There is a great deal of talk from Estonians about how Russians are invaders. That was certainly the case many years ago, but most Russians living their now were born there and in many cases so were their parents. I accept that many believe that people should be punished for the actions of their parents, grandparents etc. I am not one of them.

2) Most of the trouble in Tallinn has been caused by general purpose hooligans. The sort of people who in the UK would be rioting because their football team lost.

3) It is perhaps instructive to compare Estonia with Lithuania. They both have very similar 20th century histories, but everyone who was a permanent resident on the day that Lithuania gained independence became a citizen. The same is not true in Estonia where there are still a great number of stateless Russians.

4) Estonia gained independence in 1991, therefore, any Russian younger than their mid-thirties can't regret that they no longer run the country, since they never did.

5) Is Amnesty International prejudiced against Estonians? I don't know, but they certainly have plenty to say about their language laws (http://web.amnesty.org/library/Index/ENGEUR510012007?open&of=ENG-EST). In my non-legal opinion, Estonia is going to end up in front of the EU for breaching EU laws designed to protect linguistic minorities.

6) Very little known fact: Consider my wife's grandmother. She lives in Russia in the same cottage she was born in and speaks only Russian. She sounds like the sort of person that the Estonians would want nothing to do with doesn't she? But, between the two world wars, the bit of Russia where she lives was part of the first Estonian Republic. As a result of this, the Estonian government will give citizenship to her and any of her decedents. My wife's cousin doesn't speak a word of Estonian and apart from 2 short holidays has never set foot in the place, but because of her grandmother she now has an Estonian and thus EU passport. Meanwhile, many Russians who were born in Tallinn and have lived there all their lives, but also don't speak Estonian remain stateless. This seems a little inconsistent to me.

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