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GPSMap 60c

Started by lrbaldwin, October 29, 2009, 12:44:21 PM

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lrbaldwin

Several years ago I got this gps but used it only connected to my laptop with Delorme Street Atlas...hubby drives, and I'm the navigator.  Now that I have the teeny little Delorme receiver, I would like to put some maps on the Garmin for Frank to use on his bike when we ride.  At this point I'd like to have detailed road maps for Virginia and for the NC Outer Banks.  This GPS doesn't use a SD card, so I'm wondering how much map data I can put in its internal memory, and which maps from this site I should use.

Thanks,
Linda

lrbaldwin

#1
Thanks.  I'm totally new to the hand held gps world.  I don't mind having to remove one map and install another.  I'd like to get the most detail I can, at least I think that would be good).  Would the SE map give as much detail asw a strictly NC map?

I'm in the car now about an hour away from Duck.  I'll be able to download maps and update MapSource tomorrow on our DSL, access in the car is too slow.  I'm really excited about getting maps for this old gps.

What a great site and terrific members!!!

Linda  

lrbaldwin

OK, we've arrived in Duck, and I see that the only CD I have is Trip & Waypoint Manager.  From what I've read in the forum today, I think I need another CD that must have come with the GPS.  I don't think I have that.  Is there a way I can get it?

Thanks,
Linda


maps4gps

MapSource is included in Trip & Waypoint Manager.

Which NC map is more detailed depends on how you define detail.
John M. used a contour interval of 20' for all the 48 States - not too useful in flat areas.  I varied the CI using the CI on the published USGS topo quads as a 'model' - hence 5' in flat coastal areas.
John M. used NHD 24K hydro; I used hydro from Census (as in the Ibycus mapset and a year more current) which is usually not as detailed.  There are a lot of issues with the NHD hydro in some areas; I believe was OK for coastal areas in NC and VA, however in some areas the more recent data has issues where the earlier data did not.  It is still in development by USGS.

QuoteA lot of the smaller eastern states don't have individual maps simply because John's NE and SE topos are there.
That is not correct.  I did not upload mapsets for these states because a high proportion of NED/DEM elevation data was created by using early production methods and the resulting contours often are a poor match to those on the printed USGS quads.  The PA topo/plan mapset was to test user acceptance of not including contours for 7-1/2' quads where the older production methods were used - so far the only comment was asking if I knew when USGS might be providing better data. 

Seldom

Quote from: maps4gps on October 29, 2009, 08:55:07 PM
John M. used NHD 24K hydro; I used hydro from Census (as in the Ibycus mapset and a year more current) which is usually not as detailed.  There are a lot of issues with the NHD hydro in some areas; I believe was OK for coastal areas in NC and VA, however in some areas the more recent data has issues where the earlier data did not.  It is still in development by USGS.

This is really a map making support question, but could you elaborate on the problems with NHD which are still in development?  I've been using high def NHD shape files, because when I use Tiger water I often find the streams running up hill, because of poor alignment.

Thanks,

maps4gps

Most of the issues as I see them are more a matter of consistency of detail and coverage.  Depending on your area and purpose, they may be a non-issue for you.


From downloading the NHD in Oct, 2007 (shortly after it was anounced they were 'complete) and using them for a 50 State mapset; spot checks of Oct, 2008 data; and some info from the April, 2009 NHD Stewardship meetings:

In a number of locations, polygons for the ocean and some major lakes are missing.  If a few    cases the lines for the shore are also missing.  A major issue if it occurs in your area.

In some areas, island areas were not 'cut out of' a ocean or lake polygon.

Polygons for some wide sections of rivers are missing.

Large rivers (those shown as polygons) are not named; and can not be as any large (two shoreline) stream/river in that subbasin is also part of that polygon and hence the name would also be applied/shown for the side streams.

As each USGS 7-1/2' topo 'stands on its own' (with possibly many decades between production,  source materials, etc.), the downstream (and usually larger) portion of a 'minor' watercourse may not be continued on the next quad.

Names were taking from the GNIS with a very small tolerance for coordinated differences.  Thus only about 1/3 of the waterfalls in Colorado with GNIS names have names in the NHD.  The coordinate matching was very exacting, but the feature type seems not to have been as the NHD coordinates for Lake Powell (reservoir) matched Teddys Horse Pasture (flat) in the GNIS and THP was applied to the NHD polygon.

Some featues are miscoded as to type - also occurs in the Census data.

There were I few more, but I do not recall them right now.


You can see by checking ever so often, that many of the subregions are 'revised' every few weeks (or less): ftp://nhdftp.usgs.gov/SubRegions/High/

They are aware of some of these issues.  In April their stated emphsis was on a seamless data join with Canada and Mexico; moving the NHD toward 1:4,800 resolution; and modifying the data base structure to handle some of the issues between NHD and GNIS (data base by Sept, but actual data later / much later).


Hope this helps as it is hard to determine how much to say to clarify versus being too detailed and confusing.


BTW - which version of Census were you using and what area are you authoring?
OZ made the mapset pics for my state maps and I believe only one has streams running over topo features - that was due to 'bad' NED data which USGS replaced after 18 months because of user complaints (the pic was not redone)

Seldom

Thanks for the answer maps4gps. 

The Tiger files with the uphill water were line files from 2006.  I just assumed nothing would have gotten better since then and never checked back.  Now it looks like the Tiger files overlay my NHD hydrography perfectly.  This may save me several gigabytes of storage.

maps4gps

Census had a multi year program to spatialy realign the data.  I do not remember for 2006; slightly less than 2/3s of the counties were realigned in the 2007 set (which was also when they went to shape files and yearly updates).   All counties are religned in the 2008 set.  Before realignment the data was fairly poor in many/most areas.

Seldom

Looks like the hydrography is realigned much better than the roads.  Roads are getting better than they used to be, but a comparison of St. George, UT between aerial and Tiger shows there's still a lot of work to be done.

maps4gps

Interesting.  The 'main' purpose of the realignment was the roads.  I can find a few 'errors' in my local area.

lrbaldwin

Thank all of you SO MUCH!  I've maxed out this little gps's memory with the northern beaches of the OBX and enough of Virginia to go from Powhatan in the central part of the state to Richmond.  Not bad for 24 MB I  think.

With all this terrific help, all went smoothly except for the DSL download of NE US which took at least 5 hrs. I have no idea why it was so slow (11-21K/sec).  I even tried switching to the neighbors on either side of us who have wifi with cable, no difference.

Thanks to all,
Linda

maps4gps

seldom_sn,
   If you already have the NHD, you may want to use it.  Census seems to be replacing their hydro with more detail on a county by county basis.  They only use a code for stream/river; no intermittent.  I would expect intermittent streams to be of some importance in youir area.  Can you tell if what is intermittent in NHD is just coded stream in Census, or are they not included?
   Another source of roads would be UDOT?  IndyJpr used this for his Utah Topo.  For 4wd trails in the Moab area it was much better than the Census data.