Topo across zone boundaries

[ScottMorris]

With the new WMS capability in TopoFusion we can now display Topo maps seamlessly across UTM zones.

My question to any beta users is this:

Should we change TF to default to this way of accessing the topos?  

This makes sense for new users -- they would never see the UTM zone fuzzy tile issue.  But for existing users they'd have to redownload any topos they currently have.

I fully intend to leave the old way of getting topos in there, so if you don't want to change to the zone crossing method, you don't have to.  But I'd be curious to hear if anyone would be willing to change over (i.e. the UTM zone stuff is annoying enough to make it worth it to redownload stuff).

Another benefit of these Topos is they are in the same map projection as the new color aerials and the landsat tiles.  This would make it super easy to do photofusion exports with both topo and the color aerials.  They also clean up a few issues with switching tilesets while still in 3D mode.

Any thoughts?

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Here are the instructions for adding the WMS server to TF:

Here's a way to access the Topos in a different way:

1. On the main TopoFusion main, go to Window->WMS Custom Servers

2. On the WMS dialog, choose "Add new server"

3. Enter name = "TopoWMS"  (no quotes on all these strings)
 
4. Enter server = "terraserver-usa.com"

5. Enter request = "ogcmap6.ashx?Layers=DRG&Format=image/jpeg&Version=1.1.1&Styles=&Exceptions=se_xml"
(that should all be one line -- be careful when doing copy / paste, though it will be shown as two lines in the dialog, split at the question mark character).

6. Click "Save Changes"

7. If you want a shortcut key, hit either of the shortcut buttons.

8. choose the TopoWMS tileset in the tileset selector.

You should now have topo maps that cross UTM zones seamlessly.  

This server info will be included in the next version of TopoFusion, in minimum.

[sanewcomb]

I'm enjoying some of the new features to TF. Thank you for continuing to improve the software in numerous ways.

After an initial trial of the WMS server I have a few questions.

The images appear to be stretched horizontally. I know it is a different projection, but I thought that would primarily shift and/or rotate the image. The stretching is quite noticeable. Is the x axis, scale wise, equal to the y axis? Is TF stretching it or is the projection inherently distorted, at least in our area?

I also noticed the UTM grid feature is disabled for the WMS tileset. This is good if it does not give accurate results. I can certainly see a problem with displaying the grid(s) at the zone boundaries. I personally will not be quick to change tilesets if the grid feature will not be updated in the near future.

The WMS tilesets are not really seamless. The border or USGS map collars, approx 200 ft wide with UTM numbering, is shown along the zone boundaries. I wonder if that was added as a safety feature to give some indication that a zone change has occurred.

Also just noticed the USGS logo stamped on every tile. It is somewhat annoying, though rather small on the 2M tiles at the printing resolution I use.

After writing out this post I will probably not be using the WMS tileset in its current form. I think there is a real issue in "taping" together the USGS topographic maps across zones. Most people (who use GPSs to navigate) probably use UTM coordinates to navigate, and it would potentially be very confusing if they printed out a map across zones and tried to use a UTM overlay grid to figure out where they were. I would print out two different maps on either side of the zone boundary.

The WMS aerial tilesets are a different matter. It is very nice to see the photographic images merged over the zone boundaries. These aren't really used to navigate so I have less of an issue with "taping" over zone boundaries with these.

Thanks again for adding new features to the program.

Steve
Tucson, AZ

P.S. Oh, to answer your question I would say no as a default due to the potential confusion in using printed maps that would contain two different coordinate systems.

[ScottMorris]

Thanks for the input, Steve.

The WMS topo tiles are indeed stretched in the X-axis.  The effect gets more prominent the further north you go.

It's just the difference between UTM projection and geographic / Mercator.  

I think I'll add the WMS as an optionally added server, but not make it default.  Having UTM projected tiles is still nice, and the zone boundary doesn't affect too many people.

Any other opinions?

[jocoyn]

Since I was playing with batch download today and thought I would try WMS - I was surprised when I could not get the UTM grid and found this thread on a search.

Opinion - keep the option for the UTM grid. How else are you going to take a field map with you and plot your location unless you have a fancy mapping GPS and - GPS has continued to improve over the years but is not 100% even now.

Up until topifusion, the only thing that kept me bound to Maptech was the ability to print with UTM grids.

[ScottMorris]

Right, there is no UTM grid available in TopoWMS since it is not in a UTM projection.  The UTM grid lines would be skewed.  But, I am getting several requests for UTM grids in lat/lon projection tilesets (eg color aerials) so I will likely soon take a crack at adding it.  I'm not sure what the implications of tilted grid lines are for field use, though.  Any thoughts on that?

[jocoyn]

Hmmm what is a "tilted grid line"? There are most certainly depths of mapping that I am totally new to.

To me, the ability to do a combo map with a color / topo and being able to see the grid lines from the topo** would have more use.

**not the ones from the scan which are usually NAD27, but the WGS84 grid.

[ScottMorris]

It's hard to describe, but this image might help, though it doesn't describe it perfectly:



Right now the UTM grid lines in TF are straight up and down because the topo maps themselves are in the UTM projection.  That figure shows UTM zone boundaries, but the concept for any given UTM line is close to the same.

In the TopoWMS (and Color Aerial) tilesets the grid lines would look more like in the figure.  I don't really use grid lines when I print maps (I prefer following tracks I've pre-laid out in TopoFusion before going out into the field) so I don't know if that totally screws up the usage of the grid or not.  I suppose it still gives you a good estimate as to your coordinate by looking at which grid square you or a feature is in.

[jocoyn]

Now that you mention it I am used to gridded maps where the grid lines are not exactly veritical but in my own zone it is barely perceptible on a small scale. And when I calibrate the aerial and pull up topo it "fits" and the roads and streams etc are in the "right spot" relative to the topo.

So I gather the old topo maps we have downloaded are rotated to fit to vertical grid lines whereas the WMS maps are not?

Some of it may be old school. We can't always count on having computers up and running at a search scene though and being able to manually track positon of your crew by having them call in coordinates is a must and there have been times when we have had to give them a bearing to navigate to a pick up point for transport etc.  So I am always using a grid reader or, with topofusion maps, the little hashmarks to log points manually.

So there is little "preplanning" for them to work with - the are basically given an area to work however they best see fit and then we download their track when they git back- it is not like they ever go out with a route marked on a GPS to follow.

It has only really been a few years where GPS have been reasonably reliable in the heavy eastern deciduoius forests.......and it can still get dicey in a deep wooded ravine.

[ScottMorris]

Yep, I definitely understand you guys have different requirements and I really like to support the SAR folks.

It seems quite a few people would like UTM grids, or other grids, on color aerials, topo WMS, etc.  So I will make it a priority.

thanks.