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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?

#111

Post by squeaky-clean »

robotastronaut wrote: post #106
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…

Nitpicky, but useful for anyone interested in spatial data: WGS-84 is not a "GPS standard" but rather a geographic coordinate system and is usually paired for consumption with a projection like wgs 84 web mercator to view those 3d coordinates on a 2d plane. Super interesting stuff and reconciling these standards across the globe is a really fun problem, and one you'll likely run into if you ever find yourself dabblin…

I don't know if I would call it nitpicky for this example :P Thanks for correcting me, I've edited the comment.

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

#112

Post by zokier »

vanusa wrote: post #7
zokier wrote: post #4

tldr: Israeli-US agreement limited resolution until July 2020, and Gmaps hasn't gotten around to updating the imagery since.

The bigger question of course is why the "agreement" was made with the Israelis, and not with the Palestinians directly.

Because Israel has more deeper pocketed lobby groups in US?

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

#113

Post by jrochkind1 »

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…

My memory says that US government GPS at one point intentionally introduced reduction in accuracy/resolution as well, but they stopped, which was part of what led to the commercial GPS revolution (along with cheaper tech of course).

Let's see... Wikipedia seems to confirm:

> During the 1990s, GPS quality was degraded by the United States government in a program called "Selective Availability"; this was discontinued on May 1, 2000 by a law signed by President Bill Clinton.

https://en.wikipedia.org/wiki/Global_Positioning_System

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

#114

Post by adolph »

panarky wrote: post #67
caymanjim wrote: post #34

Earlier quoted context omitted.

The short answer is no. High-resolution imagery comes from low-orbit satellites, which make a complete orbit about every two hours, and image long, narrow strips with each pass, taking days to image the whole planet. There are many of these satellites: commercial, non-military (publicly-accessible) governmental, and governmental (secret), of varying resolutions. These are also supplemented by aerial (plane) imagery.…

Starlink is seeking approval for tens of thousands of low-earth-orbit satellites. Each one will have high-bandwidth network connections. It doesn't seem intractable to put cameras on each one and stitch their feeds together for imagery that's maximum 30 minutes old for any arbitrary point on the globe. And the market for near-real-time imagery might be even larger than the market for internet connectivity.

The next generation of LEO ground imaging satellites will be significantly larger than Starlink units.

Now, with the resolution relaxation from the United States Government that went into effect on February 21, 2015, you have access to an even clearer view of the ground with 30-centimeter resolution commercial satellite imagery.

https://spacenews.com/a-detailed-view-of-the-ground-with-30-...

WorldView-3 is the industry’s first multi-payload, super-spectral, highresolution commercial satellite. Operating at an altitude of 617 km, WorldView-3 provides 31 cm panchromatic resolution, 1.24 m multispectral resolution, 3.7 m short-wave infrared resolution, and 30 m CAVIS resolution. WorldView-3 has an average revisit time of less than one day and is capable of collecting up to 680,000 sq km per day, further enhancing the Maxar collection capacity for more rapid and reliable collection.

https://www.maxar.com/constellation

WorldView-3: Mass: 2800 kg (6200 lbs) Power: 3.1 kW solar array, Altitude: 617 km

Starlink: Mass: v 1.0: 260 kg (573 lb) Power: 6 kW solar array, Altitude: 550 km

https://lilibots.blogspot.com/2020/04/starlink-satellite-dim...

https://en.wikipedia.org/wiki/Starlink#Constellation_design_...

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

#115

Post by captainmuon »

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…

I've found that the maps match the GPS of my phone exactly, but the satellite pictures are shifted.

Does that mean: 1) My GPS module also gives out obfuscated coordinates when in China or 2) Google uses shifted satellite images?

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

#116

Post by betterunix2 »

elmomle wrote: post #37
betterunix2 wrote: post #21

Earlier quoted context omitted.

Should they have negotiated with the Palestinian Authority, which only partially controls the West Bank, or with Hamas, which took control of Gaza and proceeded to murder leaders from other Palestinian political parties? It is kind of hard to know who the "official" representatives of the Palestinian people actually are due to the failure to establish a functional Palestinian state or government.

I wish the recent history of Palestine were different too, but it seems unkind to use language that implicitly blames Palestinians as a people--or the factions that now hold power--for these issues. Literally any people on Earth would probably have a similar history, and be in a similar (or worse) place with respect to government, if they faced similar pressures for such an extended period of time.

How did I blame the Palestinian people? The fact is that they do not have a functioning government, and the government they have is not in a position to negotiate on their behalf when it comes to Gaza. The faction that controls Gaza is not even recognized as legitimate by the PA (which is supposed to represent the Palestinian people).

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

#117

Post by op00to »

rsync wrote: post #57
mvanaltvorst wrote: post #43

Earlier quoted context omitted.

planet.com can get you a ~12 images per day [1] for a reasonable price. If cost really isn't an issue, I'm confident you could strike a deal with planet.com to place their next few new satellites into the specific orbit you want to up the frequency even more. [1]: https://www.planet.com/pulse/12x-rapid-revisit-announcement/ , as of June 2020.

What is that reasonable price? It is not given on the page you linked…

Are you looking at a 7-8 figure upside to your deal? It's reasonable. Are you looking for fun? Unreasonable.

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

#118

Post by redfern314 »

panarky wrote: post #67
caymanjim wrote: post #34

Earlier quoted context omitted.

The short answer is no. High-resolution imagery comes from low-orbit satellites, which make a complete orbit about every two hours, and image long, narrow strips with each pass, taking days to image the whole planet. There are many of these satellites: commercial, non-military (publicly-accessible) governmental, and governmental (secret), of varying resolutions. These are also supplemented by aerial (plane) imagery.…

Starlink is seeking approval for tens of thousands of low-earth-orbit satellites. Each one will have high-bandwidth network connections. It doesn't seem intractable to put cameras on each one and stitch their feeds together for imagery that's maximum 30 minutes old for any arbitrary point on the globe. And the market for near-real-time imagery might be even larger than the market for internet connectivity.

This is more or less the business model of Planet [0], which is imaging the whole Earth every day with around 200 satellites. (No affiliation, but I previously worked for a different smallsat company.) It would be possible to get a higher visitation than that with more satellites, but it may not be cost-effective (e.g. someone might be willing to pay $X for a subscription to daily images, but not $(48*X) for half-hour images).

I also doubt you could just slap a camera on Starlink satellites. Even ignoring payload size/weight, power consumption, etc, you're typically fighting 3 different constraints when you decide which way to rotate your satellite (sun exposure for power, antenna direction for high-bandwidth network, payload direction if you have cameras or other directional sensors). They're not going to want to try to deal with that for the first iteration of their fleet.

[0] https://www.planet.com/products/planet-imagery/

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

#119

Post by throwaway894345 »

caymanjim wrote: post #34
deadalus wrote: post #5

Is it possible to have real-time live-feed of the entire planet? If cost isn't an issue, would something like that be possible?

The short answer is no. High-resolution imagery comes from low-orbit satellites, which make a complete orbit about every two hours, and image long, narrow strips with each pass, taking days to image the whole planet. There are many of these satellites: commercial, non-military (publicly-accessible) governmental, and governmental (secret), of varying resolutions. These are also supplemented by aerial (plane) imagery.…

What limits the field of view of these LEO satellites? Why can we not have high resolution images of wider swaths? Is it something like the number of "receptors" on an imaging cell, or would wider angle lenses significantly distort the imagery?
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