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The Lowdown on Lidar

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271–280 of 284 posts

Re: The Lowdown on Lidar

#271

As a college intern at a national lab my boss' boss got a speeding ticket on the military base we worked on. He spent some time doing research and when he presented his evidence in court the judge apparently told him he wasn't going to have to pay the fine but the judge wasn't going to find him not guilty because he wasn't going to risk invalidating all speed gun findings. I don't recall if it was lidar but it's funn…

If you were really gung-ho about getting it marked as not guilty, could you appeal it and move up the chain?

Re: The Lowdown on Lidar

#272

Speed radars are good for speed traps, but not so great to prevent speed related incidents. They share the same fatal flaw with all other single-point speed meters: You can just slow down for a minute, while you pass by the speed trap, and then speed up for the rest of your trip. Instead, a 2-point speed meter (i.e. license plate readers every few miles, measuring time between matching reads) system is superior becau…

As someone who daily drives a highway [1] that is marked 15 MPH below what it ought to be (as almost all highways are), I hope this system never comes to fruition. Now, automated tagging of morons who stare at their phone while driving? Bring it on. Those fuckers are a plague. [1] The Mass Pike (I-90); which is a toll highway that is marked 65 MPH, on which traffic averages 75 MPH, and 80 MPH is well under the speed…

On the other hand, as someone who also believes speed limits are too low, I sometimes wish they _were_ enforced to draconian extremes because then the 95% of drivers who just ignore the law instead of trying to change it might actually get off their asses and vote.

Re: The Lowdown on Lidar

#273
post #4

I confess I was expecting to not care for this. I'm not sure how any of it should be surprising, as it seemed fairly straight forward analysis of the tools. That said, this was a ridiculously fun read. More detailed than expected for some parts, and always informative. I'm glad it did not come across as anti speed detectors. Really more of a "know the limitations."

I hope he realizes this, as much as I hope everybody else realizes this, that the only reason why he got the violation reduced was because he brought his attorney on board. Anybody who lives in California whose contested a ticket knows that 9/10 times (if not even more than that) judges side with the officers -- whether they have a strong case or not -- the State of California certainly doesn't want it's residents to…

> I wonder if his attorney cost more than the actual citation?

Doesn't really matter -- getting a[nother] point on your license can be more costly log-term (insurance rates, having to re-take drivers test, etc).

Re: The Lowdown on Lidar

#274
post #262

Earlier quoted context omitted.

But, HN titles are content. They are part of the conversation about the article. I agree that authors should be able to title and summarize their own work, but only in that work. They shouldn't be given any special control of the conversation about that work, which is what HN is. I don't see the purpose of having mods vet all titles or summaries. I don't think titles need any special blessing by an elite caste of use…

What's your response to this? https://news.ycombinator.com/item?id=6572466

Ah, thank you. That's what I assumed the policy was, but I wasn't sure if it was implicit or explicit. Now I know.

I guess the point I'm attempting to argue is that this particular policy is suboptimal and should be changed. Of course, when a policy or consensus exists, we should follow it. When it's a bad policy, we should follow it until we change it or remove it. I think we should change this.

My position basically boils down to a worse-is-better argument. I think the desire to maximize accuracy with original titles actually harms the conversation more than inaccuracies and editorializing in information-packed summaries.

What matters to me in this case is the signal-to-noise ratio, not the absolute level of noise in the data. Original titles can be "cleaner" and less noisy, but they also have relatively little information, or signal. I would rather have twice the noise if it gives me three times the signal.

I even see the noise as useful in a way. It adds color. Even when a title is inaccurate, it's sometimes interesting to think about how or why it is inaccurate. A little mess never killed anybody, and can even keep us healthy. Ultimately, if I'm so busy I don't have enough time to be occasionally mislead by a click-bait title, then I don't really have time to spend on HN in the first place.

I think the right way to deal with inaccurate titles is either to simply ignore them, or maybe to downvote them and to upvote duplicate posts with better titles. But won't HN then turn into reddit? I don't think so.

See, I think we try to fix too many things with laws where we should instead use social pressure. The reason that Americans don't litter very much isn't that it's now a ticketable offense. It's that we have decided that litterers are idiots and everybody hates them. The reason many subreddits are cesspools isn't the lack of rules, it's that they're populated by people who haven't collectively figured out a better way to behave -- or who don't particularly value the benefits of that different behavior. Adding a new rule won't fix anything if people don't understand and accept the purpose behind the rule. And if they understand the purpose, they usually don't need the rule.

Someone could argue that HN is something of a cesspool because so many comment threads go off topic. Like this one. Some people despise that. In general, though, HN users generally seem to appreciate an off-topic conversation so long as it's adding value. What we don't approve of is comments that don't add value. But, we don't need rules for that. It's just our commonly accepted behavior. Other groups have different values, and that's ok.

Re: The Lowdown on Lidar

#275
post #272

Earlier quoted context omitted.

As someone who daily drives a highway [1] that is marked 15 MPH below what it ought to be (as almost all highways are), I hope this system never comes to fruition. Now, automated tagging of morons who stare at their phone while driving? Bring it on. Those fuckers are a plague. [1] The Mass Pike (I-90); which is a toll highway that is marked 65 MPH, on which traffic averages 75 MPH, and 80 MPH is well under the speed…

On the other hand, as someone who also believes speed limits are too low, I sometimes wish they _were_ enforced to draconian extremes because then the 95% of drivers who just ignore the law instead of trying to change it might actually get off their asses and vote.

Likewise, I secretly hope vehicle speeds would be electronically limited (say, radio-controlled by highway transmitters) for the same reason.

Re: The Lowdown on Lidar

#276

Earlier quoted context omitted.

The utilitarian argument for them is very strong. Doubtless a national numberplate recognition system would be effective at enforcing the speed limit. Once we have it, it would also be of great utility to investigate kidnappings and terrorism. And serious and violent crime. And vehicle thefts. And drug trafficking. And driving without a license, insurance, or tax. And lying about your address to get your kid into a g…

We already have numberplate recognition and its essentially on a national scale, just not completely linked up from jurisdiction to jurisdiction. License plate scanners are becoming rampant in some areas, they apparently have never been successfully blocked, all for reasons you listed and also as "license plates and vehicles don't have rights". The favored method for abusing a person's rights is to target their thing…

Perhaps I can incorporate my car, and get it some rights!

Re: The Lowdown on Lidar

#278

Earlier quoted context omitted.

If you've traveled around the country, you've invariably come across those "speed is monitored by aircraft" signs, and what you described is how they do it (tracking how long it takes cars to go from point A to B)

I've always been a bit nervous about those "speed is enforced by aircraft" signs (as opposed to "monitored"). I always get a mental picture of a aircraft strafing near my car until I slow down...

You may enjoy this image from XKCD then:

http://what-if.xkcd.com/imgs/a/87/radar_aircraft.png

Re: The Lowdown on Lidar

#279
post #71

Earlier quoted context omitted.

In France they have a system that sort of works like this, most/many highways are toll based. There are toll booths at regular intervals(every 100 miles or so). If your time between toll booths is below a certain time, they know you were speeding at some point. To get around this, my always speeding grandpere would just have us stop for gas, un cafe, etc right before each toll booth.

> To get around this, my always speeding grandpere would just have us stop for gas, un cafe, etc right before each toll booth. That sort of defeats the point of speeding. Why endanger your lives and the lives of the others if you even don't get faster to your destination as you make additional stops to "defeat" anti-speeding systems?

I don't think his speeding was a logical, reasoned thing

Re: The Lowdown on Lidar

#280

Well the author may be a clever computer scientist but he knows nothing about physics and LIDAR equipment. Pathetic I'm afraid.

Given that (1) you're an expert in these areas and (2) you found no points in the author's work worth refuting, I guess it follows that the author is actually an expert as well.
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