I’m having a hard time figuring out how to get good resolution and also the area I want.
Here are some problems I want to solve:
I want to get a large area (e.g. a city block) but the resolution is low. Can I get high resolution for a large area that I select?
I can get better resolution by zooming in. And I can do this multiple times in slightly different areas with “Add More Imagery” and in that way get higher resolution over a larger area.
How do I know what is the best resolution I can get? I might zoom in more than is needed, and therefore get a smaller area than I want. Or I might not zoom in enough, and therefore get a poorer resolution.
Anybody know how to solve this? Can anyone explain better how Add Geolocation works with respect to resolution?
Geo-location uses what I would call a hack to get the imagery. Instead of requesting proper high res imagery through some API under the hood it basically takes a screenshot of the add location dialog. For a better resolution you can start with making the dialog as big as your screen allows. You may also need to go to Window > Properties > OpenGL and enable maximum texture size.
However, it still leaves me with the puzzle of how to know when I’ve got the best resolution.
Also, I have a 4K screen. I get select the whole screen when I’m zoomed in a certain amount. But when I zoom out more “Add More Imagery” won’t let me select the whole screen. See attached screen shot (reduced by 50% so as to not upload too large an image). I can select less, but not more.
System designs are not done to allow anyone to do what ever they want when ever they want. Imagine the chaos that would result but, info is provided to you on how to tile larger areas.
“Best” resolution is very subjective what / why res do you think you need. ?
The res. is ultimately limited by a number of spacecraft design parameters, ground processor design, collection geo., sensor design ( radar, laser, optical), weather at collection time, etc.
Regarding “best” resolution.
The original image has a specific resolution. It might be 1 pixel per foot or it could be 12 pixels per foot or something else. By “best” resolution, I mean the resolution of the original image. Google Earth allows you to zoom in closer than that resolution. The result is a very blurry image. Google earth does not pixelate. i.e. when you are very close it looks blurry, not clear squares (pixels) with one color.
Mac7565, you mentioned info on how to tile large areas. I know I can grab “More Imagery”. However, choosing the next tile is awkward. I haven’t found a simple clear way to choose a bunch of tiles. I’d be interested in any info/ideas on this.
Not really confusion. For example, you can have an image with 10x10 pixels resolution and 1024x768 resolution.
If you took a photo with 10x10 pixels (of course no real camera takes such a small picture) and then blow it up to 1024x768. However the blown up image would have no new information. The blow up could look much different depending on the algorithm for blowing it up.
The method they describe here is for printing an image. It is essentially the same as grabbing a screen shot. As far as I can tell it would have none of the geolocation information. That’s the nice thing about grabbing the imagery in SketchUp. It has the geolocation information, so sun angles and many other things are accounted for. Also it has topographical info.
FYI 1) The resolution of over head optical sats are in the range of about 3 cm although the government recently approved ~2 cm range;
2) The res. using actual targets is basically the impulse response of the CCD plus some other contributers. Different users buying collected data may well ask for specific processing so it can be lesser resolution than what is collected
3) The Google Earth I posted shows how you can download four different resolutions from earth PRO. That is free now so hope you are using that;
4) Google Earth gets their data from IAOPG ( International Association of Oil and Gas Producers);
5) I have seen stated the tile of the data can improve res.
Interesting.
Do you know what the resolution of the IAOPG data is? What I see on Google Earth certainly doesn’t look like 3 cm. I have found that zooming in and “Adding Imagery” will give me higher resolution than when I am zoomed out. However, there is a limit. And, as noted, the resolution does not appear to be 3 cm.
Attached is a very small piece when I am zoomed in a close as I can get
Here is a screen shot that gets one of the cars, blown up in Photoshop so that you can see the pixels
There is 18 pixels from front to back of the car. Assuming the car is about 16’ the resolution would be about 1’ per pixel.
Also, I noted that “Get Location” limits how far I can zoom in. Google Earth let’s me zoom in closer, but the image is not clearer. Google Earth does not get pixelated, it just gets blurrier. Presumably it has some software that interpolates between pixels, which looks smooth but is in fact pretty meaningless, and obscures what is really known.
Resolution seems to be better in the U.S. Here is a screen shot of a street and car in California.
The location I am looking at in China is Latitude 39°14’18.67"N, Longitude 117° 1’55.05"E
Do you know what the resolution of the IAOPG data is
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They specialize in out sourcing services world wide so that is dead end has far as your question and do provide service to google earth;
The 3 cm resolution is the sat capability. Look at bottom near right corner of images and manytimes it will list the source and and you can do a serach to find its " specs" also many are listed in the GE side bar drop down at the bottom. Quickbird usually provides the best res.
If you need res better than GE provides you can contract directly but it is $$
While I cannot give you exact information, I do know that the information that third parties can get from Google Earth (third parties such as SketchUp) are of a much lower resolution than what can be displayed inside of GE itself.
It is a matter of what you want to pay for. To start with you take the CCD detectors on the space craft that are in the sub cm range size but by the time you project to ground the area they cover is very large so the actual resolution you will get is in the meter resolution or worse. Because the sat. cover a relative small area of the earth it can then take a very long time to get global coverage. Then the processing, QC checks etc takes time also so is the reason much of the data you see is months or more latent.
If you want access to the best , most recent data some released by NASA is the best but you will not get spoon feed like GE data does and will probably not know what to do with it:smiling_imp:
