Comments on: How Google Earth [Really] Works

By: khadija ali

khadija ali — Thu, 26 May 2011 10:30:43 +0000

This is all very informative, and I’m sure in the fullness of time I’ll have the IT-speak to understand most of it: my question is very simple, if someone might break this down for me. Every time I use google on my (rather slw) connection, images “download” and get clearer, so the next time I dont need to wait, they are already clear. When I lose my laptop, or upgrade, as I have done once or twice, my images are “lost” and I must start the process again. Are these images stored on my my places.kmz file? Is that what I need to back up? It seems rather small, only 7kb and I have all of Nairobi on my PC! Help pleez!

By: Dilbagh

Dilbagh — Thu, 26 May 2011 09:31:14 +0000

A lot of thanks for providing this valuable information.Never gave it a thought as to how very high resolution images are available on desktops with ease.

It was mind-boggling and at times I was in awe.Moreover,there is tinge of humor in your writing which makes the experience even better.

By: lean management

lean management — Fri, 06 May 2011 05:39:47 +0000

Thanks for letting us know about how Google earth works.Now I have a good idea about it.

By: avi

avi — Sat, 22 Jan 2011 20:31:47 +0000

I don’t think the KH series of satellites was still around by the time Keyhole started, but there are commercial companies selling aerial data using much newer versions of the same principles.

By: Artemis Air

Artemis Air — Sat, 22 Jan 2011 00:51:01 +0000

If i interpreted this correctly – I had no idea that Google used the Keyhole Satellite for the purposes of Google Earth. As I recall that was the military’s super satellite. If this is the case then there must be a newer more amazing device.

By: pallavi

pallavi — Sat, 25 Dec 2010 11:09:12 +0000

im eager to know the concept behind the google earth . coz im going to make a project on basis of this. my project includes a machine which captures the live vision of people on the earth, and detects our person .this is named as smart cam cob. will be used only by the crime investigators

By: avi

avi — Wed, 13 Oct 2010 18:26:25 +0000

Quanfu Bao, sorry, I’ll have to leave it to Google to explain this part.

By: avi

avi — Wed, 13 Oct 2010 18:20:59 +0000

Hi Chris,

Yes, they are similar. The main difference from my point of view is that clipmapping (universal texture) focuses on a single very large virtual texture that has a single point of highest resolution and tapers off appropriate to a viewing frustum. MegaTexture has some nice additions that allow it to handle multiple spatially-proximate textures that can be applied to terrain + buildings, etc.. and is more generalizable to games and rich 3D environments. Doing that is something we talked about at Keyhole when we discussed adding 3D building facades, but we didn’t go very far in that direction. So I’d describe MegaTexture as a great generalization of similar foundational ideas.

To Carmak’s credit and the world’s benefit, he doesn’t try to patent or protect any of his technology. However, to be clear, Chris Tanner’s early software clipmapping and SGI’s earlier hardware versions definitely preceded MegaTexture as far as I know. Carmack is actually friends with some of the same ex-SGI folks, which also relates to his preference for OpenGL.

By: Chris E.

Chris E. — Mon, 11 Oct 2010 20:53:53 +0000

Question:

Is this clipmapping similar to the Megatexture tech that id software announced a while back?

It appears pretty similar, and knowing those folks I wouldn’t be surprised if the underlying tech is derived from this.

By: Quanfu Bao

Quanfu Bao — Mon, 27 Sep 2010 11:03:25 +0000

Would you like explain some more details about data orgnization of Google Earth and the flow chart of spatial data index of Google Earth?
Thank you!