new map sources in Gaia
52 views
Skip to first unread message
Andrew Johnson
Feb 6, 2012, 3:57:28 PM2/6/12
to gaiagps-beta, Gaia GPS
Hey folks,
A user told us about the sources available at www.caltopo.com, and we have made them available in the app.
To add, go to Settings->Help, and click the "Add Topo Map Sources" link (the top link).
These include topos and aerials of California, as well as a USGS topo source for the continental US.
Regards,
Andrew
Morrie
Feb 8, 2012, 4:50:32 PM2/8/12
to Gaia GPS
Wow, these are far nicer topos than the other USGS topos. Same maps,
but much better scan quality.
> A user told us about the sources available atwww.caltopo.com, and we have
but much better scan quality.
> A user told us about the sources available atwww.caltopo.com, and we have
TiFlo
Feb 8, 2012, 5:05:53 PM2/8/12
to Gaia GPS
I tried them for the Adirondack High Peaks area, and I actually found
them inconsistent (green square to brown square, that sort of thing)
and lacking the pseudo slope shading the USGS topos provide (tried on
the area around Mt Marcy, Colden Mtn and the MacIntyre Range).
them inconsistent (green square to brown square, that sort of thing)
and lacking the pseudo slope shading the USGS topos provide (tried on
the area around Mt Marcy, Colden Mtn and the MacIntyre Range).
Morrie
Feb 10, 2012, 10:53:35 AM2/10/12
to Gaia GPS
I looked at Mt. Marcy and the only difference I saw between USGS topo
and the equivalent CalTopo was lack of shading (which I prefer) and
cleaner scan. What do you mean by "green square to brown square"?
and the equivalent CalTopo was lack of shading (which I prefer) and
cleaner scan. What do you mean by "green square to brown square"?
Morrie
Feb 12, 2012, 12:42:28 PM2/12/12
to Gaia GPS
I think I see what you mean by "green square to brown square". The
color correction of the scanned maps is different from section to
section, so the green forest background is different shades of green.
When zoomed out, say to 1"=5mi, the very light green sections look
brown instead of green, because the contour lines are brown. However
once you zoom in, the difference doesn't really matter and the quality
of the maps themselves is well worth it, especially trying to read the
maps outside in very bright light. I don't miss the shaded relieve --
that's mostly a distraction to me and doesn't add any information.
What I do miss though is the automatic switching of map scales as I
zoom out (to 15-minute topos, etc.), like it does for the USGS Topos.
When zoomed out even a modest amount you can't read anything on the
7.5-minute topos.
color correction of the scanned maps is different from section to
section, so the green forest background is different shades of green.
When zoomed out, say to 1"=5mi, the very light green sections look
brown instead of green, because the contour lines are brown. However
once you zoom in, the difference doesn't really matter and the quality
of the maps themselves is well worth it, especially trying to read the
maps outside in very bright light. I don't miss the shaded relieve --
that's mostly a distraction to me and doesn't add any information.
What I do miss though is the automatic switching of map scales as I
zoom out (to 15-minute topos, etc.), like it does for the USGS Topos.
When zoomed out even a modest amount you can't read anything on the
7.5-minute topos.
Morrie
Feb 12, 2012, 12:52:35 PM2/12/12
to Gaia GPS
You know, I looked at the paper topos I have and the shading of green
is inconsistent from one map to the next. What you're seeing on on
the CalTopo maps is basically the consequence of scanning printed
maps, more obvious by the fact that different ones are juxtaposed.
Another weird thing about the CalTopo Topos. Some of them (for e.g.,
Gloucester, MA) are actually aerial photos, overlayed with captions.
is inconsistent from one map to the next. What you're seeing on on
the CalTopo maps is basically the consequence of scanning printed
maps, more obvious by the fact that different ones are juxtaposed.
Another weird thing about the CalTopo Topos. Some of them (for e.g.,
Gloucester, MA) are actually aerial photos, overlayed with captions.
Matt Jacobs
Feb 12, 2012, 9:17:22 PM2/12/12
to Gaia GPS
Responding to a couple different messages here.
There are basically 3 public sources for USGS topo maps:
* The older DRG scans that Terraserver users.
* The USGS' newer "historical topographic map" scanning project
* The USGS' new "US Topo" multi-layer computer-generated PDFs
The DRGs are color-corrected to a standard set of colors, but have a
lower scan quality. The newer scans that my map layer is based off
aren't; I played around with ways to normalize colors between quads,
but delicate features like contour lines always lost fidelity. Some
of the maps use a very yellowish green that's fairly close to contour
brown.
The USGS hasn't finished scanning some states yet, including MA. For
those states, I used a mix of the older low-res DRGs and the US Topo
maps. The library I'm using doesn't support PDF layer separation, so
the US Topo maps wound up with the aerial background turned on rather
than the standard white-green vegetation layer. Some of the US
Topos used fonts that weren't present on the machines I was using for
map rendering, and the result is that you only get the largely
illegible white drop shadow, and not the actual label. Since most of
these maps will be redone when the USGS finishes scanning that state,
I didn't put a lot of effort into making sure they came out pretty.
For more information on all this see:
http://caltopo.blogspot.com/2012/01/caltopos-current-map-layers.html
A lot of the 15 and 30 minute topos the USGS has online are garbage
from a navigational perspective. I can see them being useful on a
small screen, but I don't feel like they add much when you have a
large monitor and a mouse - in fact, the automatic switching drives me
nuts sometimes. I just added a 1x2 degree layer that goes down to
zoom level 12; I'd be willing to consider a more detailed 15' or 30'
one if there's enough interest, but not by overwriting the tiles that
I currently have. If I did the layer, it would take some code changes
on Andrew's part to automatically swap the tile URL based on zoom
level.
Re: shaded relief, it's not added to the map tiles because on my
website it's a separate layer that you can mix in at whatever
percentage you want. The relief shading exists, but you'd have to ask
gaia to build support for displaying simultaneous layers into their
app. I don't know what that involves.
There are basically 3 public sources for USGS topo maps:
* The older DRG scans that Terraserver users.
* The USGS' newer "historical topographic map" scanning project
* The USGS' new "US Topo" multi-layer computer-generated PDFs
The DRGs are color-corrected to a standard set of colors, but have a
lower scan quality. The newer scans that my map layer is based off
aren't; I played around with ways to normalize colors between quads,
but delicate features like contour lines always lost fidelity. Some
of the maps use a very yellowish green that's fairly close to contour
brown.
The USGS hasn't finished scanning some states yet, including MA. For
those states, I used a mix of the older low-res DRGs and the US Topo
maps. The library I'm using doesn't support PDF layer separation, so
the US Topo maps wound up with the aerial background turned on rather
than the standard white-green vegetation layer. Some of the US
Topos used fonts that weren't present on the machines I was using for
map rendering, and the result is that you only get the largely
illegible white drop shadow, and not the actual label. Since most of
these maps will be redone when the USGS finishes scanning that state,
I didn't put a lot of effort into making sure they came out pretty.
For more information on all this see:
http://caltopo.blogspot.com/2012/01/caltopos-current-map-layers.html
A lot of the 15 and 30 minute topos the USGS has online are garbage
from a navigational perspective. I can see them being useful on a
small screen, but I don't feel like they add much when you have a
large monitor and a mouse - in fact, the automatic switching drives me
nuts sometimes. I just added a 1x2 degree layer that goes down to
zoom level 12; I'd be willing to consider a more detailed 15' or 30'
one if there's enough interest, but not by overwriting the tiles that
I currently have. If I did the layer, it would take some code changes
on Andrew's part to automatically swap the tile URL based on zoom
level.
Re: shaded relief, it's not added to the map tiles because on my
website it's a separate layer that you can mix in at whatever
percentage you want. The relief shading exists, but you'd have to ask
gaia to build support for displaying simultaneous layers into their
app. I don't know what that involves.
Morrie
Feb 13, 2012, 8:22:34 AM2/13/12
to Gaia GPS
Thanks Matt, for that great explanation. I agree that the 15' and 30'
maps are useless for navigation. However they are needed to get a
sense of where you are when zoomed out. In Gaia, if I zoom way out, I
see the overview map of the US that shows highways, lakes and major
cities, but zooming in a bit more than that I see quads so tiny I
can't really tell what I'm looking at. So one or two intermediate
layers are needed between the overview map and the 7.5' one. I don't
see the 1x2 degree layer in Gaia's CalTopo section right now, though I
do see it in the USGS Topo section (plus (I think) a 15' layer or
30'x60' layer).
My only complaint about Gaia's layer switching in the USGS Topo
section is that it switches to the larger scale map too soon. On the
iPad (and I presume this would also be the case on the iPhone), when I
zoom in on one layer slowly to read it more clearly, it switches to
the next larger scale map before I want it to, and the map is too tiny
to read at that magnification. The only layer that I can ever read
perfectly clearly is the 7.5' one, when I zoom way into it. This is
especially a problem using the iPad outdoors in sunlight when I need
to enlarge things bigger than normal to read them.
I am glad it switches layers automatically -- I just wish it weren't
so aggressive favoring the large scale map over the small scale.
maps are useless for navigation. However they are needed to get a
sense of where you are when zoomed out. In Gaia, if I zoom way out, I
see the overview map of the US that shows highways, lakes and major
cities, but zooming in a bit more than that I see quads so tiny I
can't really tell what I'm looking at. So one or two intermediate
layers are needed between the overview map and the 7.5' one. I don't
see the 1x2 degree layer in Gaia's CalTopo section right now, though I
do see it in the USGS Topo section (plus (I think) a 15' layer or
30'x60' layer).
My only complaint about Gaia's layer switching in the USGS Topo
section is that it switches to the larger scale map too soon. On the
iPad (and I presume this would also be the case on the iPhone), when I
zoom in on one layer slowly to read it more clearly, it switches to
the next larger scale map before I want it to, and the map is too tiny
to read at that magnification. The only layer that I can ever read
perfectly clearly is the 7.5' one, when I zoom way into it. This is
especially a problem using the iPad outdoors in sunlight when I need
to enlarge things bigger than normal to read them.
I am glad it switches layers automatically -- I just wish it weren't
so aggressive favoring the large scale map over the small scale.
Tiger6761
Feb 13, 2012, 12:08:17 PM2/13/12
to Gaia GPS
OK, am I missing something? on the Android app I am not seeing a way
to add a mapsource???
to add a mapsource???
Florian Panissié
Feb 13, 2012, 12:49:58 PM2/13/12
to gaia...@googlegroups.com, Morrie
Thank you Matt for clearing things up! Now all this makes much more
sense to me.
sense to me.
Le 2012-02-13 08:22, Morrie a �crit :
Andrew Johnson
Feb 13, 2012, 10:14:02 PM2/13/12
to gaia...@googlegroups.com, Morrie
First off, let me say I'm happy to say we met up with Matt today. He really has a depth of knowledge about these maps, and it was really cool to hear all about them.
Second (to Lance and other Android users) - we'll get these and other sources added to the Android app that we show on iPhone as well. Matt's topos are particularly good for Android users, because Gaia doesn't "overzoom" on Android, and Matt's topos are rendered in higher resolution, and to one deeper zoom level.
On Mon, Feb 13, 2012 at 9:49 AM, Florian Panissié <florian...@gmail.com> wrote:
Thank you Matt for clearing things up! Now all this makes much more sense to me.
On 8 fév, 16:50, Morrie<mor...@thegassers.com> wrote:
Reply all
Reply to author
Forward
0 new messages