I am working on a contour overlay/transparent mapset for the US.
I have seen posts and looked at the CN maps on Garmin's website and agree that the hydro in Garmin's City Navigator is fairly general.
What are your thoughts on expanding the scope of the contour line mapset to include NHD hydro, physical feature GNIS points, etc.?
I think it will look like a mess when overlaid on City Navigator. You are being very charitable by describing the CN Hydro as "fairly general". ;D The small lakes near me are just "blobs" in City Navigator and don't come close to the real shapes. Also, polygons on a transparent map will cover up anything on the CN maps underneath, so rivers will cover up the bridges, etc.
If you want a small sample of how it will look, try my Northern Arizona Topo Overlay.
I realize polygons in an overlay mapset will cover-up everything in the primary map and custom imagery. I expect it will also cover-up the Birdseye imagery.
I was intending to use custom types for the polygons - I thought I had read they can be made transparent; but have not tried to make any yet.
I don't think there is any form of transparency between separate maps - is there? I don't work with transparent maps myself so not sure. Within a single mapset, the best you can do is use a checkerboard pattern with one color as transparent. I think that would look bad for water which should be smooth instead of textured.
But give it a try and you may be able to come up with something.
I have no experiece with custom types - I was thinking maybe a dot pattern like is used on printed maps; however, the pixel density on a GPSr may not be high enough to look good.
Since there are so many coding issues in the Census data, I was considering a primary map could consist of transportation (+- ?) with a user choice of CN, Census or OSM (if routing was needed). Contours, hydro, etc. could be in an overlay mapset.
This is probably the easiest way to get going with custom types. For quick tests, create or modify a .typ file here then use SendMap20 and drop it into a mapset along with an .img file: http://ati.land.cz/gps/typdecomp/editor.cgi
I think the water data on CN is pretty weak; especially for hiking. For a grand canyon hike that I did I was very happy that the topo I was using had the intermittent streams because I knew it had just rained so I could use them. CN would have had nothing.
I like the idea of seperating maps but I think that most of the users that download maps would just become confused by all the choices (the Illinois topo's have pretty much all these choices now).
It would be better if CN did not have any hydro. Some users would not like it, but there would not be any conflicts with the hydro on a detailed hydro overlay mapset.
Agree with everything in one mapset is the most user friendly, and most people relate to States but not quadrangles/geographic coordinates. Overlay mapsets are also not user friendly in MapSource - no preview data for reference location.
Conversely, with contours normally being about 1/2 to 4/5 of the data in a topo mapset, having a topo mapset and a contour overlay mapset, and both PC and MAC versions has the same data on the website four times. Then consider a quad may have data from two or more States, and the same contour lines could be in 8 or 12 or more files. This will occur more often as I am changing average files size from 1+Mb to 2+Mb to utilize the larger memory card sizes with the same 4000 segment limit. Since there is little change in contours (only where USGS is updating the NED), hydro and physical GNIS POIs, a lot of uploading and downloading time could be saved if these were in a seperate overlay mapset. The user could use CN, OSM or a Census mapset for roads and streets as needed.
Quote from: maps4gps on April 22, 2010, 07:51:03 AM
It would be better if CN did not have any hydro. Some users would not like it
That might be the understatement of the day. ;D The largest base of City Navigator users are people who buy a Nuvi. They probably would wonder where the ocean went or why they couldn't see the river when driving over a bridge...
Perhaps water polygons in an overlay/transparent mapset will not be that much of an issue.
Just looked at Jim's CO transparent topo on my CO300 - the hydro polygons cover the roads; however, so do the hydro and contour lines and the labels. Same for the contour lines and labels in what I was working on. Looks like the transportation needs to be in an overlay mapset with everything else in the primary mapset.
Yes, I agree. You could make City Navigator transparent I guess (have not tried myself). However I think this site discourages these kinds of modifications...