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New Mexico Topo missing data along the West Border

Started by BH in AZ, June 08, 2010, 03:56:54 PM

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BH in AZ

I downloaded the Windows version of the New Mexico Topo last week along with the other four corner states, AZ, UT an CO plus NV.  

The installs into Mapsource went well and I created one mapset with these five states that I transferred to an SDHC card on a Nuvi 760 (firmware 4.9).

The problem is that about a 1/2 mile of mapping is missing from the NM topo along the AZ / NM border.  
I can also see a more narrow section of mapping data missing from the UT topo along the AZ / UT border.  

Here is a screen shot showing the four corners area.  Note the yellow blank area without mapping data along the west border of NM and the south border of UT.  

http://tinyurl.com/2ej7bql

When I look at the NM topo in Mapsource (6.15.11), the mapping data is still missing.  I actually created the mapset a second time just to check if I may have missed selecting the segments along the border.  All were selected.


Is this something I can fix or is it just a characteristic of the maps?    

Thanks for your help.


Nuvi 760, Oregon 450

Seldom

I think this is an author question.  I've noticed behavior like this on my Nuvi 660, but it only happened on the Nuvi.  The map segments were continuous in MapSource.

I've documented something similar between tiles in MapSource. here:

http://forums.gpsfiledepot.com/index.php/topic,1115.0.html

But that's due to a bad TDB generator in the compiler I was using.


grclark888

I tried combining the western states and had similar results with border areas with lost data on the garmin device.  I see detail on the individual maps in MapSource but they are not there on the garmin.  I suspect that when the software transfers data and builds the .img file it may take what is a blank data on one map (because it exists in an adjacent state, other side of the border) and overlays the lack of data onto the complete data fields of the adjacent state.  A stiching error between states. Just a guess.  Since MapSource is built by Garmin for Garmin it isn't a surprise that it doesn't do a good job of stitching together independently produced maps.  Clearly the problem is in the transfer process and .img file compilation.  May need to do one chip one map to insure you have all of the state's data.

Seldom

Which device, grclark888?

The border problem I describe above that occurs on my Nuvi 660 doesn't occur on my GPSMap60CSX.  Haven't noticed it on my OR300 either.

grclark888

Sorry, that's on a 60Cx.  I guess I could try to import the .img file back to MapSource to see if the information is missing which I suspect it will be. 

maps4gps

My guess:
   This is not observed in MapSource because you can only view one mapset (State) at a time.
   The border quads/tiles have data to the edge of the State; however, if that border is not perfectly aligned with lat or long (none are for any distance) there will be some 'blank' area where the data do not go to the furthest extent.  On the GPSr, this 'blank' area(s) from one data set will obscure the data from the adjacent data set.
    This might not happen in Garmin's mapsets because the 'S' (semitransparent), which is relatively new to the cgpsmapper software, is designed to eliminate this issue.

    When IndyJpr first made the Utah Topo there was also a gap in data when used with his Colorado Topo.  He was going to fix this by adding the small area of Colorado west of 109 long to the Utah Topo.  I do not know if he did so.
     I believe Ibycus also mentioned having this issue as he was building his mapset by adding the data for the States in a 'random' order.  The completed mapset is using 100k quad boundaries.

Just a guess from observations and posts - seams reasonable to me.  Can someone do a test with adjacent quads with an irregular boundary?

Seldom

Thanks, maps4gps, I think you are getting close, but not there yet. 

1) Semi-transparent is something cgpsmapper cooked up to hide its preview map primitives.  MapSource recognizes it, but BaseCamp doesn't, so you see a generalized preview layer when looking at a semi-transparent map in BaseCamp.  I pointed this out on the BaseCamp forum, and their developer said it was an "error in MapSource."

2) The borders of tiles I used for the maps I referred to above that showed the problem on my Nuvi were aligned by lat/lon coordinates, not state boundaries.

3) The weird rendering I link to above is also from aligned borders.  You have to have perfect alignment for routing to work, and while the routing works, the rendering is weird.  You don't see the problem in the BRCA-Zion-CARE map set that I uploaded because I used an older version of the mkgmap compiler.

I don't understand what data you suggest testing in your last paragraph.  If you clarify, I'll be happy to do a test.

maps4gps

I was thinking of a fairly irregular boundary between two States, each in its own mapset.
However your understanding of semi-transparent and your mapsets would indicate my guess was not correct anyway.

Seldom

It's actually missing data.



The tan polygon is Tiger shapefile of San Juan County.  I imported IMG from NM Topo into GPSMapedit.  Fortunately, the IMG files for that mapset start at the northwest.

BH in AZ

Thanks everyone for the input to my inital post. 

It appears we are discussing two separate issues. 

The first, as described in the initial post, is where the mapping data does not completely fill the map tile to the edge of the border.  In this situation, none of the map tiles overlay each other. 

The second issue brought up in a subsequent post is the situation where two map tiles overlay each other and an irregular boader for the state does not correspond with the edge of the tile.  A good example of this can been seen by building a map set with the AZ and NV Topos, then looking around the Lake Mead area.  The AZ topo overlays the NV topo, wiping out the mapping data for NV where the maps overlap. The NV side of the AZ topo map is blank because the mapping data ended at the AZ border defined by the Colorado River.   

http://tinyurl.com/337vos4

What I concluded from reading these posts is there really isn't anything the end user can do about either of these situations.  This is something that would have to be changed by the author, assuming that is technically possible. 
Nuvi 760, Oregon 450

Jimbob

BH inAZ,
In fooling with my 60CSx I find the problem much reduced or eliminated by the following.
Select only one map to view at a time (in your receiver) and when you reach a point on the border go to the next state. This works for me even with some of my home made maps enabled. It's possible that in places you may end up in no mans land for a short distance, but even this can be remedied by waypoints if depending on the GPSr for travel/location.
As to your first issue if a map does not cover a given area (which I have had little problem with but the above will work there also) then there is no way to make it do so. something we live with.

-Oz-

I will have to look into making sure I make the state the only thing selectable rather than doing it in grids.

New mexico is on deck for an update after Florida.  Just have to get back up to speed.
Dan Blomberg
Administrator - GPSFileDepot
GPS Units: Garmin Dakota 20, Garmin GPSMap 60csx, Nuvi 255W, Nuvi 250W, ForeRunner 110, Fenix 2, Tactix Bravo, Foretrex 401
See/Download My Maps!

Jimbob


evance

Has anyone else noticed that there appears to be a missing area (approx. 10 mi wide) along the entire AZ-NM border, on the New Mexico Side? 
Rino 530 HCx
ETrex legend
Nuvi 200W
Mobile XT for Windows Mobile

Seldom