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Author Topic: Google Earth snapshot  (Read 435 times)

aruyt

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Google Earth snapshot
« on: August 01, 2017, 06:06:43 PM »
I have tried searching this, and came up with one other post on this topic, but it was on another site, and I wasn't 100% sure of the answer given.  I understand how to use Google Earth to create custom maps, based on numerous YT videos, as well as Garmin's own instructions.  So, my question is there a simple way to take a snapshot of a Google Earth satellite image, and upload that directly to Basecamp or a Garmin unit?  What it seems like you have to do now is take a screenshot of the area you want, then save that as a JPG, then add it back into GE again as an image overlay.  Seems redundant, and it's very hard to get the image precisely in the correct location.  It just seems like there is an extra step that if I could remove, would make adding a snapshot satellite image much simpler.  Basically, is this possible?

Boyd

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Re: Google Earth snapshot
« Reply #1 on: August 02, 2017, 04:58:10 AM »
There were a number of programs to do just this and Google shut them down. It is against Google's terms of service to do what you want. Read their license agreement sometime. It says you are only allowed to use their data in their own proprietary interface. You are specifically forbidden from downloading their imagery and using it in another program or another device.

Mobile Atlas Creator used to be able to do this but it can't anymore. However it does an excellent job of making maps from other sources where it is permitted. http://mobac.sourceforge.net

There are other sources of free, high quality aerial imagery but you will have to find them for your area. In my state (NJ) there's a treasure trove of really good imagery (better than Google IMO) that goes back through the years. I have shared a file that will let you access this all with a few clicks in Mobile Atlas Creator. There's probably something similar in other states, but I haven't taken the time to research it.

I have switched to Mobile Atlas Creator's format for the maps I make and distribute myself because it runs on Windows, MacOS and Linux. It's free and open source, unlike Garmin's software. Once you have a map in their format, you can export it for use on Garmin handhelds, iOS and Android devices. Takes a little effort to learn how to use it, but it's worth the effort IMO.
« Last Edit: August 02, 2017, 05:00:09 AM by Boyd »

aruyt

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Re: Google Earth snapshot
« Reply #2 on: August 03, 2017, 06:34:03 PM »
Thank you, I'll check it out.

Question though.  Are other free maps directly "uploadable" to handhelds?  Because if I still have to go through the same process as before, it kind of negates the benefit. 
« Last Edit: August 03, 2017, 06:42:30 PM by aruyt »

Boyd

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Re: Google Earth snapshot
« Reply #3 on: August 04, 2017, 04:24:19 AM »
I assume that this is the "process" you're talking about? https://www.garmin.com/us/products/onthetrail/custommaps

That is a really awkward and simplistic method only suitable for trivial map projects. There are much better ways to make this kind of map. The Mobile Atlas Creator software will let you do it on a large scale without any monkeying around with manually adjusting the image. It uses data imbedded in the imagery to do all of that for you. But you need to find online imagery for the area you want, and may also have to write a "mapsource" file to access it. This gets rather complex so if you can't find an existing mapsource file, it may be too complicated for you.

Another great program for creating this kind of map is G-Raster, the author is a member here: http://moagu.com/?page_id=155

And there is also mapc2mapc, the author of that program is also a member: http://www.the-thorns.org.uk/mapping/

There was another program that did exactly what you want. Have never used it but assume it no longer works because of Google's restrictions. But you can check it out here: https://googletrail.codeplex.com

You need to understand a bit about this type of map to appreciate the issues though. Garmin introduced this map format in 2009 and I believe I was the first person to upload a map in that format to GPSFileDepot. Here's one of several that I posted on this site: http://www.gpsfiledepot.com/maps/view/239/

But Garmin intentionally crippled this format, obviously they were concerned that people would make their own maps instead of buying their products. As originally introduced, you could only load 100 "tiles" on your GPS. That is really limited, for example if you used a USGS topo map like the one I made above, you could only cover an area less than 10 miles x 10 miles. If you use high resolution aerial imagery it's even worse, you can only cover a 2 mile x 2 mile area. So this kind of map has limited uses. Garmin's newer (and more expensive) handheld units can cover a somewhat larger area, but still very limited, about the size of 3 USGS 24k quads.

Aside from these limits, this kind of map only works at a few zoom levels and is very slow to scroll and zoom on the GPS. IMO, this is ridiculous in 2017. It has nothing to do with technical limitations, this kind of map worked very well using software called OziExplorer on cheap little GPS units 10 years ago and had none of these size limits. Garmin simply doesn't want you to use this kind of map as an alternative to their own products

This kind of map works much better on current phones and tablets too. It zooms quickly through a large range of levels and there are virtually no limits on the map size aside from the amount of memory on your phone. That is why I have stopped making Garmin maps and my Garmin GPS units (there are a bunch of them) are sitting unused in my closet. :)

aruyt

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Re: Google Earth snapshot
« Reply #4 on: August 05, 2017, 04:29:55 PM »
I understand what you are saying.  I'm not a Garmin fan in the least, but they basically ARE the market for handhelds.  Phones are not as reliable, from my experience, deep in the backcountry, or perhaps I haven't found the best app and/or way to use my phone in such situations.  There is one app I use on my phone called "Offline Maps" which allows me to download and save (at whatever resolution I want) satellite maps from a variety of sources, though the Bing satellite maps are the best alternative to Earth (and in some cases better).  Still, I'm much more comfortable using my dedicated GPS device, as several times I've literally needed it to find my way out of a sticky situation.  Honestly, adding satellite imagery to the Garmin was kind of a novelty, and I'm satisfied with the results I've gotten using that awkward and cumbersome method in GE.  I'll probably continue to create small scale image overlays in this manner, simply because I've learned how to do it.  I didn't want to make this some difficult and time consuming task, like you said, it's 2017, and you'd *think* it would be a very straight forward process. 

thanks again for your help!

Boyd

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Re: Google Earth snapshot
« Reply #5 on: August 06, 2017, 03:18:49 AM »
Have you used Garmin Birdseye? That is really the easiest way to get satellite imagery on Garmin devices, and at $30 for unlimited downloads the price is reasonable. Garmin created a separate format for this kind of map, the .jnx file. This allows coverage of a huge areas (50,000 map tiles IIRC).

There are some hacks that allow you to create your own maps in this format, but it has been decided that this is not appropriate for discussion at GPSFileDepot.

aruyt

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Re: Google Earth snapshot
« Reply #6 on: August 07, 2017, 07:06:14 PM »
I've read that Birdseye images are not of the highest resolution, not as good as Google Earth at maximum resolution.

I'll look into your non-advice and see what I can find out.  ;)

Boyd

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Re: Google Earth snapshot
« Reply #7 on: August 08, 2017, 03:45:56 AM »
My Birdseye subscription lapsed many years ago. It used to be possible to download it to Basecamp without purchasing, but it wouldn't work on the GPS without a subscription. Not sure if that is still the case.

When it launched, they said the resolution was 2 feet per pixel, which makes it sub-meter at least. 1 foot per pixel is more typical of current aerial imagery, such as the USGS HRO (High Resolution Orthophotography).

I posted a comparison on another forum back in 2010 using the 1 foot per pixel New Jersey state imagery. At that time, Birdseye was using the same imagery (since it is free) but it was lower resolution. I've read that the quality of Birdseye can vary considerably between different locations so "caveat emptor". :)




« Last Edit: August 08, 2017, 07:08:17 AM by Boyd »