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Why is the Gaza Strip blurry on Google Maps?

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Re: Why is the Gaza Strip blurry on Google Maps?

#431

Post by austinprete »

GekkePrutser wrote: post #424
khuey wrote: post #234

Earlier quoted context omitted.

After KAL007 was shot down by the Soviet Union in 1983 Reagan announced the fuzzy GPS signal would be publicly available. The US government didn't turn off Selective Availability until the late 90s.

That's weird though as a reason. KAL007 was so far off course that the distortion of SA wouldn't have mattered. It only distorted location by a couple hundred metres at most.

I read the GP as saying that SA GPS was originally made available as a result of the KAL007 crash, so presumably they didn’t have access to GPS at all on the flight? Then much later the SA restriction was removed, unrelated to a plane crash.

Re: Why is the Gaza Strip blurry on Google Maps?

#432

Post by humaniania »

freewizard wrote: post #200
squeaky-clean wrote: post #97

Not really related to the article at hand, but I've been on a bit of a Google Maps binge the past couple weeks. I learned a few interesting facts, blurry Israel being one of them. Another strange thing I found that might not be super well known (I didn't know about it) is that all GPS data in China is offset by a nonlinear psuedo-random amount. If you turn on the satellite view in Google Maps and look at various citi…

What I learned a few years back about this is the official (un)obfuscating implementation was distributed to licensed companies in binary .dll/.so/.a , and not allowed to be redistributed or reverse-engineered. Licenses are only given to local companies, and foreign companies may only buy service from them. That's why if you reverse engineer Google Map or Apple Map app, they all make real time API calls to do the con…

"they all make real time API calls to do the conversion on servers"

Can't imagine why anyone would want that to happen.....

Re: Why is the Gaza Strip blurry on Google Maps?

#433

Post by nl »

sequoia wrote: post #418
nl wrote: post #295

Earlier quoted context omitted.

> If we're trading references, can you show me some where the BBC refers to Paris as "one of the most densely populated places in the world?" "Tricks from the most densely populated city... Paris is one of the most densely populated city in the EU with relatively few green spaces." https://www.bbc.com/reel/video/p06sbtzz/tricks-from-the-most... > The reason I consider this claim "misleading" is that I never see the "…

From your examples only Bangladesh is referred to by reporters (not as a quotation) as one of the most densely populated in this case “countries” (which is much easier to count than “places”) in the world . (“Most densely populated places” means something different as of course cities are “places” and the definition of place is highly debatable as this thread shows.) Kudos & good examples. I still think this meme is…

> From your examples only Bangladesh is referred to by reporters (not as a quotation) as one of the most densely populated in this case “countries”

Not true. Only is a quote (the Rwanda one) and two of the four quotes are not about countries (Raqqa - a city, and "densely-populated areas").

I partially deal with your quibbles on the definition of "place" here: https://news.ycombinator.com/item?id=27190788

But I think it's fair to compare similarly geographically sized areas, preferably with somewhat similar political status (ie, there's a big difference between a very dense city surrounded by countryside to support it, vs a city state with no surrounding support area)

It's hard to find many places as big as the Gaza Strip (365 sq km) that are as densely populated (5610 people per square km).

Dhaka is the most closely comparable city: 306 sq km with a density of 29,069 ppl/sq km. But a city isn't comparable to a territory like the Gaza Strip. That is more similar to islands, enclave or isolated country.

On Wikipedia's list[1] Singapore (722 sq km, 7,894 ppl/sq km), Hong Kong (1106 sq km, 6781 ppl/sq km), Bahrain (778 sq km, 1,982 ppl/sq km), and Malta (316 sq km, 1,633 ppl/sq km) seem the obvious comparisons.

The Gaza strip obviously sits right up there amongst them. It is difficult to argue it isn't one of the most densely populated places in the world looking at comparable "places".

[1] https://en.wikipedia.org/wiki/List_of_countries_and_dependen...

Re: Why is the Gaza Strip blurry on Google Maps?

#434

Post by csteubs »

Nextgrid wrote: post #390
csteubs wrote: post #286

Earlier quoted context omitted.

Correct. It sounds a bit far-out (and it is) but we've proven the feasibility with a testing group of around 300 passengers using a multitude of different phones/altitudes/conditions/routes. GPS works in airplane mode, so we pre-cache target coordinates based on the filed flight plan and alert the passenger to hold the device to the window when overflying the target. The gyroscope is used to provide feedback on phone…

What's the user experience of this and what are the incentives for users to do this? How much are they paid?

UX on the flight contributor side is currently a low-touch app that accepts the user's flight number and prompts for their seat selection (assuming a commercial flight). We load an image correction profile based on whether the seat is fore or aft of the wing in order to correct for the blur caused by engine exhaust, after which we cache the image task coordinates we anticipate they'll be flying over. We provide a code for free in-flight wifi (actually 2--one for each side of the plane) that can be redeemed after completing a simple calibration task while taxiing or shortly after takeoff. The calibration looks at window opacity, occlusions, and considers atmospheric conditions for each leg of the flight.

In order to maximize battery life and prevent user fatigue, we only alert the user to begin recording when they're approaching a task coordinate by referencing the cached coordinate with the current GPS coordinate which is readily available even in Airplane mode. The "workload" for test users so far averages about 5 alerts per flight or 5-10 minutes of "recording", typically shortly after takeoff and prior to landing. We're using Lobe to train an ML model with the image feeds, so we're working on implementing a Captcha-style post-flight survey where a few sample images taken in flight are presented to the user for first-pass labeling. If a user completes this survey, they're rewarded with additional airline miles as a thank you

There are plenty of other opportunities to gamify the recording process and we've been taking cues from apps like Waze and OpenStreetMaps to inform some of these potential reward features. Possibilities include revenue sharing, free flights after reaching milestones, travel gear, etc. I remember flying Spirit years ago and they always had a fun way to reward the unlucky souls in the middle seat by putting a sticker on one of the tray tables. The passenger sitting in the "lucky" middle seat got a free round-trip ticket which I've always thought was really cool, so perks like those are top of mind as well.

Tl;dr - we're intent on keeping the UX transparent, engaging, and unobtrusive for the recorder--point, shoot, disembark--while rewarding them in kind for their time and effort.

Re: Why is the Gaza Strip blurry on Google Maps?

#435

Post by this2shallPass »

jussij wrote: post #355
plaidfuji wrote: post #342

This link title is extremely misleading to the point of being disingenuous and provocative. The title of the linked article is “Israel-Gaza: Why is the region blurry on Google Maps?”... because the entire Israel / Gaza / West Bank region is blurred in the exact same way. There is no preferential blurring of Palestinian areas. The clear answer is to prevent actors on both sides from using Google’s satellite imagery to…

Israel can get all the detailed imagery it needs by just launching a reconnaissance aircraft or drone. So on that basis I would say it only stops the Palestinians from getting imagery of the area. Now considering the fact Palestine only has rockets and not missiles, I doubt that imagery is of much value to them. Call me cynical, but I suspect the more important reason to keep these images blurred might be to stop the…

I don't know the technical distinction between rockets and missiles. Hamas has some guided explosives that other people that know more about this than I do call missiles. They used to only have unguided rockets - not anymore, for at least 6 years.

"The Russian-made Kornet anti-tank guided missile, often called ATGM as an acronym, is accurate and effective. It has a range of around 5.5 kilometers and has been used by Hamas and other terrorist groups for years. In 2015, Hezbollah fired several ATGMs against Israeli Humvees on the border."

https://www.jpost.com/arab-israeli-conflict/what-do-hamas-an...

https://www.jpost.com/israel-news/why-anti-tank-missiles-pos...

Re: Why is the Gaza Strip blurry on Google Maps?

#436

Post by qart »

azernik wrote: post #220
qart wrote: post #212

Earlier quoted context omitted.

You have a completely wrong idea of the laws of orbital dynamics. If satellites don't want to keep burning tons of fuel, they will orbit the center of the earth, not its axis. The only situation where your comment could apply is if the satellite is orbiting only above the equator. All of this, completely disregarding the economics of satellite mapping, their operational limits, etc.

Note I said "at a similar latitude". A satellite at a given inclination will trace out a ground path oscillating back and forth between D degrees north and D degrees south, where D is its inclination, with latitude varying sinusoidally with time. So it will spend different amounts of time at different latitudes, hence choice of inclination depending heavily on observation/communication target. However, for any given…

There are so many incorrect and vague things here, but rather than listing them out, I point back to my counter examples. Zooming in on Kumasi, Ghana should show you why you're wrong. Look at the mosaic lines. There are both N/S lines of disparity as well as E/W lines of disparity of resolution.

Use your own example, if you wish. Zoom in on Taiwan, and look at the cars. Next, zoom in on King Abdullah Economic City, Saudi Arabia at the same latitude. Look for cars there.

Verify if your explanation fits the data.

Re: Why is the Gaza Strip blurry on Google Maps?

#437

Post by throwaway5412 »

sequoia wrote: post #242
jcranmer wrote: post #142

Earlier quoted context omitted.

You're probably missing this listing: https://en.wikipedia.org/wiki/List_of_countries_and_dependen... Where Gaza listed as its own country, it would be one of the densest, since it's basically a city and its urban sprawl and nothing more (like the other densest entries on the list). Of course, Gaza is itself arguably only part of Palestine, but the West Bank itself is pretty dense (see how high Palestine ranks on tha…

Looking at the country list, I see Israel is the #5 most densely populated country in the world. And Bnei Brak is the #5 most densely populated city, far more densely populated than Gaza. Bnei Brak was hit by rockets this week. Can you link me to some articles that refer to "Hamas firing rockets on Bnei Brak, one of the most densely populated cities in the world"? Or "on israel, one of the most densely populated coun…

> If not, my question for you is: why do we see this phrase so commonly in reporting on Gaza but not on other more densely populated areas?

One difference is that most of its residents aren't allowed to leave, from my understanding.

Re: Why is the Gaza Strip blurry on Google Maps?

#438

Post by cookguyruffles »

ocdtrekkie wrote: post #186
acomjean wrote: post #180

Earlier quoted context omitted.

When I was a civil engineer last century gps accuracy was an issue because people wanted to use gps for surveying. They came up with a system that would use 2 receivers and a radio between them to get much higher accuracies. https://www.e-education.psu.edu/natureofgeoinfo/book/export/... I think the US Government can also shut it off at a moments notice.

They could, but multiple governments now publicly broadcast from similar constellations, so it wouldn't have nearly as much benefit for them to do so. Modern dirt cheap receivers can pick up European, Chinese, Russian, etc. constellations for location just as well as the American one.

Always wondered about this, can overlapping systems be used simultaneously for higher reliability or precision?

Re: Why is the Gaza Strip blurry on Google Maps?

#439

Post by js4ever »

sudosysgen wrote: post #419
slg wrote: post #389

Earlier quoted context omitted.

Oops, I made that more confusing by trying to note everyone was a Palestinian when the place was called Palestine. By "non-Jewish Palestinians" I was trying to refer to the predominately Muslim and predominately Arab group that we now just call Palestinians. There was and still is a population of Christians in the area and there presumably was some larger population of foreigners in the area when it was under foreign…

Everyone is still a Palestinian nowadays though. The reason why there are less Christian Palestinians is because a lot of them were deported or fled shortly after the Nakba. A lot of them would come back if Palestine was restored, but most of them are legally prevented by Israel from coming back. Not even Hamas or Hezbollah wants Palestine to be a single religion or single ethnicity state, so I don't really understan…

Christians are killed in palestinans parts like in most Muslim countries ... So clearly you are completely wrong and partisan

Re: Why is the Gaza Strip blurry on Google Maps?

#440

Post by baybal2 »

squeaky-clean wrote: post #97

Not really related to the article at hand, but I've been on a bit of a Google Maps binge the past couple weeks. I learned a few interesting facts, blurry Israel being one of them. Another strange thing I found that might not be super well known (I didn't know about it) is that all GPS data in China is offset by a nonlinear psuedo-random amount. If you turn on the satellite view in Google Maps and look at various citi…

> But Google Maps doesn't do it, for political reasons I suppose?

FYI: Google has never really quit China. It has running offices in Beijing, Foshan, and, recently, Shenzhen.

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