Welcome, Guest. Please login or register.

Login with username, password and session length
Forums Search:  


Author Topic: How should I tile my custom maps?  (Read 5159 times)

Todd_S

  • Jr. Member
  • **
  • Posts: 6
  • Karma: 0
    • View Profile
    • http://www.myspace.com/bigredtaco
How should I tile my custom maps?
« on: December 08, 2008, 06:11:09 PM »
This is my first post here so hopefully these questions haven't been addressed elsewhere. I'm not sure if I'm using proper terminology so I hope I make some sort of sense.

I have been successfully making street maps using GIS data from various sources for the past several months now. They work in several Garmin units including my GPSMap 60CSx, GPSMap 76S and the GPSMap 76CSx that I have at work. I use ArcGIS to edit the data and reproject it to UTM, then I import it into GPSMapEdit to compose the map, and then use cGPSMapper to process a Garmin IMG file. I use SendMap to transfer the IMG file to the Garmin units.

So far, I have been using county boundaries as the borders for these maps (since that is how the GIS data that I am using is distributed) but I don't think that is the most ideal way to break them up. For those of you who are making maps, what sort of boundaries are you using to create each individual map? For example, are you using something like the 1:250k or 1:100k USGS topo map boundaries or perhaps something similar?

I'd also like to add contour lines to my maps now that I have the process almost completely figured out now. I have downloaded the DEM data for the area that is covered by the 1:100k USGS topo map for San Bernardino, CA and DEM2Topo chokes on it when it gets near the end of the process. I have it set for 1000 ft major, 500 ft intermediate, and 40 ft minor contours. The process completed when I accidentally had it set for meters instead of feet and it also completes when I process DEMs that are half the size of the 1:100k area that I am trying to cover.

I guess the two questions are somewhat interrelated. How big of an area to you guys use for each of your maps and how large of an area will DEM2Topo generate contours for? The county I live in is rather big (area wise) so I was trying to cover as large an area as possible. Perhaps there is an easier way that I have yet to discover for splitting my data down into smaller map tiles.

Thank you.


-Oz-

  • Map Maker!
  • Administrator
  • Expert Advisor
  • *****
  • Posts: 1580
  • Karma: 28
    • View Profile
    • GPSFileDepot
Re: How should I tile my custom maps?
« Reply #1 on: December 08, 2008, 06:21:51 PM »
I use 1degree x 0.5degree.  This gave me always under 8mb files.  On the other hand if I were doing just roads I would go with larger segments.

On the other hand for dem2topo; I don't use it anymore so i can't tell you.  But generally it should make it through a whole standard tif (which I think is 1x0.5).

What are the specs of your computer?

And are you aware ibycus has taken the road data and made a map for the whole us? http://www.gpsfiledepot.com/maps/view/19/
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!

Todd_S

  • Jr. Member
  • **
  • Posts: 6
  • Karma: 0
    • View Profile
    • http://www.myspace.com/bigredtaco
Re: How should I tile my custom maps?
« Reply #2 on: December 08, 2008, 07:04:44 PM »
The PC that I was running DEM2Topo on the other day has dual quad core Intel processors in it (they show up as 8 2333 MHz processors) with 4GB of RAM (but it's Windows XP Pro so it sees just over 3GB of RAM). I'm guessing that should be sufficient to run DEM2Topo. The funny thing is my old 3.6 GHz P4 with 3GB of RAM seems to run the cGPSMapper process a bit faster than the dual quad core machine I have at work.

I have seen the ibycus map data but I believe he used TIGER data which is really out of whack and out of date still for San Bernardino County, CA. I work for the county with GIS so I have access to really up to date street data for our county which is one reason why I've been working on making my own maps (the other reason is I'm having fun making my own maps).

« Last Edit: December 08, 2008, 07:13:44 PM by Todd_S »

-Oz-

  • Map Maker!
  • Administrator
  • Expert Advisor
  • *****
  • Posts: 1580
  • Karma: 28
    • View Profile
    • GPSFileDepot
Re: How should I tile my custom maps?
« Reply #3 on: December 08, 2008, 10:31:37 PM »
That should have been way more than enough.

I have switched to using gdal_contour which comes with fwtools.

see this:
boxerboy: You run it just with the smallest interval.

For example if I want 40 ft I just use
gdal_contour -a elev -i 12.192 feet.tif minor.shp
because 12.192m = 40ft.

Then I use a query to do minor, intermediate, and major contours at 40, 200, and 400ft respectively.

Code: [Select]
ALTER TABLE contours ADD COLUMN mp_type character varying(50);
ALTER TABLE contours ALTER COLUMN mp_type SET STORAGE EXTENDED;
ALTER TABLE contours ADD COLUMN name text;
ALTER TABLE contours ALTER COLUMN name SET STORAGE EXTENDED;
ALTER TABLE contours ADD COLUMN tmp integer;
ALTER TABLE contours ALTER COLUMN tmp SET STORAGE PLAIN;
UPDATE contours SET elev = elev*(1/0.3048);
UPDATE contours SET name = elev;
UPDATE contours SET mp_type = '0x20';
UPDATE contours SET tmp = elev/200;
UPDATE contours SET mp_type = '0x21' WHERE elev/200-tmp < 0.0001 AND elev/200-tmp > -0.0001;
UPDATE contours SET tmp = elev/400;
UPDATE contours SET mp_type = '0x22' WHERE elev/400-tmp < 0.0001 AND elev/400-tmp > -0.0001;
ALTER TABLE contours DROP COLUMN temp RESTRICT;
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!

Todd_S

  • Jr. Member
  • **
  • Posts: 6
  • Karma: 0
    • View Profile
    • http://www.myspace.com/bigredtaco
Re: How should I tile my custom maps?
« Reply #4 on: December 09, 2008, 10:36:49 AM »
I'll have to take a look at FWTools and see if I can figure that out. I see it's open source software so I can't argue with the price.

-Oz-

  • Map Maker!
  • Administrator
  • Expert Advisor
  • *****
  • Posts: 1580
  • Karma: 28
    • View Profile
    • GPSFileDepot
Re: How should I tile my custom maps?
« Reply #5 on: December 10, 2008, 09:50:10 PM »
Yea, thats always nice :)
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!