Whenever possible, I do route planning with Google Earth. Google Earth’s 3D imagery allows me to fine-tune a route and identify features I might otherwise miss in two dimensions.
But Google Earth is losing the resolution battle with the other imagery powerhouse, ESRI. I’m willing to trade resolution for 3D exploration in many applications, but not all. I want higher resolution imagery for identifying rapids on remote rivers. Here is an example of the difference in resolution, from unusable in Google Earth to unbelievable in ESRI Worldview.
The good news is, there are several ways to work with the ESRI imagery, including pulling it into Google Earth!
CalTopo
If you are unfamiliar with CalTopo, here is a basic introduction. ESRI Worldview is not available in CalTopo by default; you have to load it manually.
- Go to http://caltopo.com/.
2. Select Add New Layer from the menu on the left side of the page and choose Custom Source.
3. In the Custom Source dialog box, provide a name for the layer and paste the url below in the URL Template field. I’ve increased the Max Zoom from the default 16 to 20. Zoom levels above 16 aren’t always available, but if they are, I want them.
https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}
If you have a CalTopo account ($20/year), click the Save To Account link so that you don’t have to repeat this process. Saved layers can be found in the layer menu in the upper right, at the bottom of the list of options, under Your Layers.
Now I can add waypoints at each rapid and identify which side of the river might be easier to portage. At the end of my work in CalTopo, I save the waypoints and portage line segments to be imported into Google Earth and combined with the rest of my existing route work. But you could certainly do all of your route planning within CalTopo.
Google Earth
You can pull ESRI Worldview imagery directly into Google Earth two ways.
The free option is to pull the kmz directly from arcGIS: https://services.arcgisonline.com/arcgis/rest/services/World_Imagery/MapServer/kml/mapImage.kmz (direct download). This source is a bit sluggish and does not go to as high a zoom level as what we can get from CalTopo. It also doesn’t seem to work on Linux computers.
The second option is to pull the layer via CalTopo’s servers. You need a CalTopo account, the basic subscription level costs $20/year.
Sign in (upper left) and click on your account name (email address) in the upper left corner. Select the Your Account tab under the View Account window. Click on the KML hyperlink toward the bottom of the window to download the superoverlay.kml file.
Open superoverlay.kml in Google Earth. Select Your Layers from the bottom of the list, and move the folder with your ESRI Worldview layer out of the Temporary Places folder so that you don’t have to repeat this process after restarting Google Earth.
Note that you might want to save other layers as well; I used the USGS 7.5′ layer for my topo map work in Google Earth.
GaiaGPS
ESRI Worldview is available at the premium subscription level of GaiaGPS. Select the Layers & Overlays icon from the buttons on the left, then Add Map Layers at the bottom, Satellite Imagery –> World Imagery.
If you don’t have the premium subscription level, you can manually load the ESRI layer. Follow the directions in the Custom Load Google Earth Imagery section of my Gaia tutorial, but use the ESRI URL instead of the Google Earth URL.
My routes are all going to end up in GaiaGPS anyway (so that I can load them onto my phone for the trip), so why not use the Gaia website in the first place? The reason is that Gaia’s web application tile servers are prohibitively slow. GaiaGPS is absolutely the easiest way to work with the ESRI basemap. I just get impatient. The hassle of loading ESRI into CalTopo pays for itself after 10 minutes of mapping.
View-only
There are a few easy ways to view the ESRI layer without the ability to add waypoints or routes. These are my go-to in the exploration phase of trip planning.
- Bing’s aerial imagery service
- Direct from ESRI, with timestamps!
The direct from ESRI option allows you to determine the date that the imagery was collected. In this case, the river imagery was collected August 31st, 2015. The timestamp is very helpful for anticipating water levels at other summer months.
Does this work on a MAC? I tried to take an ESRI GIS class but had to partition my hard drive to access their software with IBM software. Don’t quite have the room without getting a newer computer.
Hi Jack- all of these websites run on any operating system… mac, PC, Linux. You don’t have to download any software. That said, many applications don’t play well with Microsoft internet Explorer.
Luc, do you think that ESRI has purchased the Worldview imagery from Maxar/Digital Globe?
Maxar/Digital Globe satellites (https://en.wikipedia.org/wiki/DigitalGlobe) include WorldView-1, 2, 3, and 4: the 1m and better resolution stuff that looks good on GE where Google bought it instead of posting the free 30 m Landsat and they offer this amazing imagery called “Vivid” that they host on Digital Globe’s EVWHS site (https://evwhs.digitalglobe.com/myDigitalGlobe).
Unlike the archived Worldview-1,2,3,4 and other Maxar/DG products on EVWHS you can’t download it. So tantalizingly good, but unavailable!
We often download the DG WV panchromatic and multispectral stuff for our treeline research and look at on GE Pro as a SuperOverlay.
It looks like some of that primo WV imagery, previously only a pay-to-play resource, is available from ESRI using the method you describe . Nice discovery!
The final link of this post, “Direct from ESRI” shows the imagery provider and data source when you click on the map. In the region I used for my example, the imagery is from Maxar, WV02.
GE’s source label (text at bottom of the image… sometimes) isn’t very useful to me. Landsat / Copernicus (the free 30m imagery) in my example, and Maxar in nearby regions.
It seems likely that the EVWHS imagery will be more publically available someday!
That Cal Topo + ESRI URL is spectacular. Thanks for showing us that Luc.
Awesome, thanks!
The entire Gaia web app is. Incredibly. Slow. It’s my main excuse for not having my Gaia folders well organized. I keep waiting for this to get better, it’s kind of a surprising weakness.
Thanks for tracking this stuff down too. Seems like an updated list of best servers available would be handy but that sounds like a headache to maintain solo.
And yet Gaia’s app servers are just fine. My guess is that it has something to do with the public tracks. I think the site got unusable after the re-design that moved public tracks. But even with public tracks off… unusable.
I don’t really mind the 12-site approach. It feels like taking the best of each site rather than using one site with a bunch of compromises. Hmm. Sound familiar 😉
Luc, have you ever utilized the AGOL Scene viewer (https://www.arcgis.com/home/webscene/viewer.html)? Although it is view-only and doesn’t allow you to design routes, it does drape nicely over the ESRI terrain layer associated with the DigitalGlobe Vivid image mosaics (though ESRI doesn’t provide much metadata for the terrain layer). Additionally, there is no display scale limit on the tiling schema like that you mention with the free GE method.
There also used to be a workaround for accessing the metadata on the different tiles in Bing via a third party-website. I can send you the older version of a doc we had that outlined the workflow, if you aren’t already familiar with it and felt like tinkering to get metadata on Bing. I have noticed many places where Bing was more recent than Google imagery – or at least was a few years back.
Isn’t it so cool how many options we have for imagery the state now compared to just 10 years ago?? Thanks for this post.
Thanks so much Luc! Perfect timing as this has already helped me to identify some rapids on our North Cascades packraft traverse. As winter approaches, I am curious if you have any of the latest tips on how to find the best imagery for ski tour planning?
Depending on the application, I’ve used Google Earth’s time control or ESRI’s Wayback to look for winter images. But winter imagery generally isn’t as available. One tool that I really appreciate for shoulder season trips is Sentinel imagery since it is often just a few days old and gives you a sense for snow line, etc.
https://thingstolucat.com/2019/03/11/satellite-imagery-near-realtime-sources/
If you haven’t looked, I’d also suggest taking at look at FATMAP. Available in both app and website. So far, with some limited use, I’ve really enjoyed the 3D experience. And I can save areas onto my phone and use it live, while off grid. I did so in Denali National Park earlier this year on a bike-packing trip .
Thanks Andrew, it has been a few years since I tried FATMAP and I bet it has matured a bit. I agree that 3D functionality adds a lot!
Awesome, thanks for sharing this, I have been searching for a way to use ESRI in caltopo and could not locate a WMS/WMTS link. This is awesome!! However, I was looking at ESRI imagery here (https://www.arcgis.com/home/webmap/viewer.html?useExisting=1&layers=ab399b847323487dba26809bf11ea91a) and notice this layer looks a lot greener, I really like this color scheme better. Do you know how I might locate a link like the one provided, to use with the ESRI imagery I linked to above? Thanks again for sharing this info!
oh wow, that does like like a useful layer (“clarity”). I just clicked around in Esri and wasn’t able to find a tile server for it. The “Source” link doesn’t work, but I’m not certain that is what we are looking for. Maybe it will be made available at a later date?
Thanks for sharing this! I had only ever known about and used Google earth.