Iron Hiker wrote:I was surfing some photos of Mount Rainier on here and discovered this remarkable recently-posted view from Brunswick Mountain in British Columbia, north of Vancouver:

http://www.summitpost.org/view_object.p ... _id=486827

According to the website www.heywhatsthat.com, the straight-line distance on the map between the two peaks is approximately 195 miles. The red "visibility cloak" confirms that Brunswick and Rainier are intervisible with each other, and it may also be possible to see Rainier from even farther away (ex. Mt. Garibaldi).

I used my program to check NNW from Rainier, and it appears that one should be able to see Rainier from Quiver Peak, in Garibaldi Provincial Park, at a distance of 225.8 miles (363.4 km). Here is the location of Quiver Peak: http://www.mytopo.com/maps.cfm?mtlat=50.04780&mtlon=-122.78685

This is the farthest distance I found in that direction that should have a view of Rainier. It is possible because of the low elevation of the Seattle area. The view actually does not go over Puget Sound like the view from Brunswick does.

gingerking wrote:what an interesting subject!
i come from eastern oregon and i can vouche of the long views in the blue and strawberry ranges. i wonder about the view from the strawberrys towards the alvord desert? the steens are pretty far out there and im pretty sure that you can see them from a few locations in the blues.
ill have to do some homework.

You can see Steens Mountain even on a hazy day from the Strawberries. You can also see Strawberry Mountain from Steens in the south or even Bachelor in the west. You can see Eagle Peak in northern california from Steens Mountain, I am curious if Shasta has been seen from Steens Mountain. I suspect it should be visible, you can see Shasta from Warner Peak just to the west.

Thanks for the link to the Brunswick photo. It's fantastic!! I've just had a look at the labels and it's bursting at the seems. I will remove some of them and then post it on our Marmota blog once I have permission from the author.

Hi,
Chipps is on holiday and he will not be reachable for the next two weeks (lucky him!).
We work together on Marmota.

Day Hiker wrote:

Chipps wrote:We've also studied theoretical situations originally pointed out by Jonathan de Ferranti ( http://tev.fbk.eu/marmota/blog/2008/10/ ... an-update/ ) although I guess that finding an actual photo of this is almost impossible.

In that image, what does the flat green area represent? I'm not familiar with the geography there, but I looked at that location based on the coordinates, and the view is north-northeast over land, not ocean, correct? Is the land really flat like that?

In that image, colors are proportional to altitude (no shading effect), so the flat green area represents a big region approximately flat. I've never been there, but I think the land is really flat like that.

Day Hiker wrote:I am able to get elevation data for the entire planet, online from USGS. But the data outside the U.S. are 3-arc-second, which is not very high resolution. They are SRTM data, and there are quite a few holes, often in inconvenient places, such as the south slopes near the summit of Aconcagua.
Do you have a better source for global elevation data, for places like Italy and BiH?

We use SRTM data from CGIAR-CSI and, where available, DEMs from Jonathan's web site viewfinderpanoramas. Resolution is not very high, but it is usually enough to render mountains that are at least few km away.

miczanin wrote:In that image, colors are proportional to altitude (no shading effect), so the flat green area represents a big region approximately flat. I've never been there, but I think the land is really flat like that.

That makes sense. I wanted to make sure I understood where the view is.

miczanin wrote:We use SRTM data from CGIAR-CSI and, where available, DEMs from Jonathan's web site viewfinderpanoramas. Resolution is not very high, but it is usually enough to render mountains that are at least few km away.

I also used STRM data for the views between Rainier and British Columbia. I cannot get anything else for areas outside the U.S.

Like you wrote, the resolution is good enough when viewing large objects. My biggest problem with the data is the holes. A big hole in the wrong place has the potential to delete an entire peak, and there is no way to interpolate the data to fix that problem.

I will check out the STRM data from the link you provided. I see that it "has been processed to fill data voids," but I would guess they used interpolation to do so, which means the same potential problems for peaks.

I wrote my own interpolation subroutine for the SRTM data from USGS. But I must separate land regions from ocean because the holes in the data show as zeros, just like ocean does.

Day Hiker wrote:My biggest problem with the data is the holes. A big hole in the wrong place has the potential to delete an entire peak, and there is no way to interpolate the data to fix that problem.

The advantage of using CGIAR-CSI data is that there are no holes, and sea and ocean are correctly separated from the land (i.e. ocean has 'NODATA' value). They mainly used interpolation to fill in SRTM holes, so sometimes, as you said, there are missing mountains. Last time I checked, the upper 3000m of K2 were missing!

Luckilly, Jonathan provides alternative DEMs (not global coverage, not based on SRTM) that are pretty accurate. We use them as a first choice, and CGIAR data elsewhere.

miczanin wrote:

Day Hiker wrote:My biggest problem with the data is the holes. A big hole in the wrong place has the potential to delete an entire peak, and there is no way to interpolate the data to fix that problem.

The advantage of using CGIAR-CSI data is that there are no holes, and sea and ocean are correctly separated from the land (i.e. ocean has 'NODATA' value). They mainly used interpolation to fill in SRTM holes, so sometimes, as you said, there are missing mountains. Last time I checked, the upper 3000m of K2 were missing!

Luckilly, Jonathan provides alternative DEMs (not global coverage, not based on SRTM) that are pretty accurate. We use them as a first choice, and CGIAR data elsewhere.

Ouch. Three thousand is a lot of meters to be missing! That is a good example, for sure, especially since it's a well-known large mountain. It is a shame that NASA didn't make more passes with the shuttle to fill in some of those holes.

Do you have a link to the other data from Jonathan that you mention? Is it available to the public (me)? What regions are covered?

Day Hiker wrote:Do you have a link to the other data from Jonathan that you mention? Is it available to the public (me)? What regions are covered?

Sure, data is available from his website http://www.viewfinderpanoramas.org/

In particular, follow the link Digital Elevation Models. There is also an interactive coverage map: just follow the link below the title of the Digital Elevation Models page.

Cool. The link is bookmarked now. Thanks!

One morning out of three summers working at the 12,500' Barcroft facility of White Mountain Research Station in eastern California I was able to see clear across Nevada and into Utah. There was a map/ridge profile at the station claiming the view that morning to be 264 miles.

Clydascope wrote:One morning out of three summers working at the 12,500' Barcroft facility of White Mountain Research Station in eastern California I was able to see clear across Nevada and into Utah. There was a map/ridge profile at the station claiming the view that morning to be 264 miles.

Just a preliminary result... about 270km away. more details later...
from 37.58382, -118.23733, 3820m

miczanin, that's too far to the south. I was looking towards Ely, Nevada, or Delta, Utah, not Vegas.

MoapaPk wrote:I also question the accuracy of that program. I've seen the Spring Mts from White, and they never appeared bright red, and never had names floating above them.

Yes, obviously he has used image processing, HDR, etc. He may have even used PB&J and a BLT. Someone should start up a hate site. And create a profile with the member's name + "LIES" at the end.

Clydascope wrote:miczanin, that's too far to the south. I was looking towards Ely, Nevada, or Delta, Utah, not Vegas.

I can also check that direction next. I am currently checking due east, about to Signal Peak in southwest Utah, since that is about the distance you mentioned, and you said you were looking at Utah.

www.viewfinderpanoramas.org has the pano from White Mountain Peak, north of the Barcroft Station and 1,750' higher......

http://www.viewfinderpanoramas.org/pano ... E-MP-N.gif
http://www.viewfinderpanoramas.org/pano ... E-MP-S.gif

The farthest east it seems you can see from there is to Troy Peak and Mount Irish - 157 miles away. That's nowhere close to Utah, however.......but a long way you can see still, to both Hayford and Charleston Peaks, so not too bad.

Interesting that the display at the station and the view to Charleston were about the same number - differing only in the unit used - miles/kilometers. Maybe it was a mistake of those??