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Reverse geocoding is hard

shkspr.mobi

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Re: Reverse geocoding is hard

#81

Post by cmcconomy »

1970-01-01 wrote: post #74
robin_reala wrote: post #72

Earlier quoted context omitted.

It’s a closed and proprietary system that contains locations like master.beats.slave near Brooklyn and whites.power.life in Washington (to pick just a couple of examples off the top of my head). If your only requirement is “human readable” and assumes the human knows how to read and pronounce English words then I guess it kinda does.

>and assumes the human knows how to read and pronounce English words I hit a dozen random benches. If these are the low requirements, W3W would and does do a great job for openbenches: https://openbenches.org/bench/random/

so would google's plus-codes,

https://maps.google.com/pluscodes/

Re: Reverse geocoding is hard

#82

Post by sbarre »

ryandrake wrote: post #52
sinuhe69 wrote: post #26

Not my area of expertise, but is this not a form of perfectionist problem? I mean, most places have a clear and simple address. For the rest, either a human can solve it, or we can make a few examples and let an AI do the work. We can go back to them later and revise them if we need to. Addresses don't change often, so I think things can stay the same for a long time. Except for emergency dispatch and a few high-prof…

You can call it perfectionism or you can call it "doing it right." I think this gets at a fundamental difference in philosophy among [software] engineers: We have a problem with a lot of edge cases, where a "good enough" solution can be done quickly. What do we do? There's a class of engineers who say 1. Do the "good enough" solution and ignore/error on the edge cases--we'll fix them later somehow (may or may not hav…

> Unfortunately (in my view), group #1 is making all the products and is responsible for the majority of applications of technology that get deployed.

This is an interesting take, and I think I see where you're coming from..

My first thought on "why" is that so many products today are free to the user, meaning the money is made elsewhere, and so the experience presented to the user can be a lot more imperfect or non-exhaustive than it would otherwise have to be if someone was paying to use that experience.

So edge cases can be ignored because really you're looking for a critical mass of eyeballs to sell to advertisers or to harvest usage data from, etc.. If a small portion of your users has a bad time or experiences errors, well, you get what you pay for as they say..

And does that kind of pervasiveness now mean that many engineers think this is just the way to go no matter what?

Re: Reverse geocoding is hard

#83

Post by nradov »

atoav wrote: post #19
Dachande663 wrote: post #13

Fun fact that was dredged up because the author mentions Australia: GPS points change. Their example coordinates give 6 decimal places, accurate to about 10-15cm. Australia a few years back shifted all locations 1.8m because of continental drift they’re moving north at ~7cm/year). So even storing coordinates as a source of truth can be hazardous. We had to move several thousand points for a client when this happened.

In the past year or so I have thought a lot about how to design tables and columns within databases and there is nearly nothing that wouldn't get more robust by adding in a "valid_from" and "valid_till" and make it accept multiple values. Someone's name is Foo ? What if they change it to Bar at some point and you need to access something from before with the old name? If you have only a name field that has a single v…

Anyone who works with human names should take a look at the HL7 V3 and FHIR data models, which were designed for healthcare. They support name validity ranges, and a bunch of other related metadata. It can be challenging to efficiently represent those abstract data models in a traditional traditional database because with a fully normalized schema you end up needing a lot of joins.

Re: Reverse geocoding is hard

#84

Post by nradov »

modeless wrote: post #75
andrew_eu wrote: post #53

I have a memorable reverse geocoding story. I was working with a team that was wrapping up a period of many different projects (including a reverse geocoding service) and adopting one major system to design and maintain. The handover was set to be after the new year holidays and the receiving teams had their own exciting rewrites planned. I was on call the last week of the year and got an alert that sales were halted…

Wow, I had no idea that Taiwan controlled an island less than three miles from mainland China, essentially surrounded by China in a bay. (The main island is 80+ miles away.) I'm really surprised China has allowed that for 80 years. Unsurprisingly, the beach looks like this: https://www.google.com/maps/place/Shuang+Kou+Zhan+Dou+Cun/@2... Also interesting that there's a Japanese island only 60 miles from Taiwan on the…

If the Chinese Communist Party decides to escalate the pressure on Taiwan then one likely scenario is some sort of blockade against those small islands close to the mainland.

Re: Reverse geocoding is hard

#85

Post by AlotOfReading »

jandrewrogers wrote: post #65
AlotOfReading wrote: post #22

Earlier quoted context omitted.

GPS coordinates actually account for the motion of the Earth's tectonic plates. The problem is that it's a highly approximate model that doesn't accurately reflect areas like Australia very well. There's a great visualizer of the coordinate velocity from the Earthscope team: https://www.unavco.org/software/visualization/GPS-Velocity-V...

GPS coordinates do not account for tectonic motion. It is a synthetic spheroidal model that is not fixed to any point on Earth. The meridians are derived from the average motion of many objects, some of which are not on the planetary surface. The motion of tectonic plates can be calculated relative to this spatial reference system but they are not part of the spatial reference system and would kind of defeat the purp…

The corrections are incorporated into the datum. WGS84 is updated every 6 months to follow ITRF by changing the tracking station locations as the plates move around.

Re: Reverse geocoding is hard

#87

Post by meindnoch »

867-5309 wrote: post #71
meindnoch wrote: post #60

Earlier quoted context omitted.

>GPS coordinates actually account for the motion of the Earth's tectonic plates. What?

accounts for (something) , phrasal verb meaning "considers; incorporates; takes on board" as opposed to the more obvious "gives rise to; is responsible for". I had to read twice too

Yeah, I know what "accounts for" means.

I just can't comprehend how GPS coordinates could account for the tectonic plates' motion. Never heard of such a thing, and can't see how it would work on a conceptual, mathematical level.

Re: Reverse geocoding is hard

#88

Post by meindnoch »

AlotOfReading wrote: post #85
jandrewrogers wrote: post #65

Earlier quoted context omitted.

GPS coordinates do not account for tectonic motion. It is a synthetic spheroidal model that is not fixed to any point on Earth. The meridians are derived from the average motion of many objects, some of which are not on the planetary surface. The motion of tectonic plates can be calculated relative to this spatial reference system but they are not part of the spatial reference system and would kind of defeat the purp…

The corrections are incorporated into the datum. WGS84 is updated every 6 months to follow ITRF by changing the tracking station locations as the plates move around.

That's about correcting the ground stations' coordinates. It doesn't help keeping your house's GPS coordinates fixed. If the tectonic plate your house is built on moves a meter over the course of a decade, then your house's GPS coords will change in the lower decimals, and eventually your government's land registry will need to update those values.

Re: Reverse geocoding is hard

#90

Post by XorNot »

pavel_lishin wrote: post #35
Dachande663 wrote: post #13

Fun fact that was dredged up because the author mentions Australia: GPS points change. Their example coordinates give 6 decimal places, accurate to about 10-15cm. Australia a few years back shifted all locations 1.8m because of continental drift they’re moving north at ~7cm/year). So even storing coordinates as a source of truth can be hazardous. We had to move several thousand points for a client when this happened.

Damn! 7cm per year feels blazing fast when you consider the fact that it's a whole continent.

I mean I'm still mind blown that the Three Gorges dam in China literally changed the rotational speed of the Earth, and thus the length of the day.
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