Welcome, Guest. Please login or register.

Login with username, password and session length
Forums Search:  

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Topics - Boyd

Pages: 1 2 3 [4] 5
General Discussion / USGS "US Topo" project
« on: June 29, 2011, 12:40:02 PM »
Has anyone else looked at these yet? http://nationalmap.gov/ustopo/index.html

I have tried downloading 3 different quads and cannot open any of them. They are packaged as .zip files but 7-zip, Windows and Globalmapper all say the archive cannot be opened. I tried download from both here:


And here:


But had the same problems. BTW, the new national map viewer (link above) seems to be to be very nice. Faster and easier to use than the old one.

GPSr Units / Garmin introduces the Montana handheld
« on: May 18, 2011, 05:26:22 AM »


Wow, now this is cool.... but really expensive (650t is $700, no pricing yet on the others but probably around $600 without the pre-loaded 100k topo). Dual orientation 4" screen at  480x272, dual power options and finally a handheld with a speaker so this can replace your auto gps.

Using The Maps/Garmin Software / Mapsource Weblinks
« on: February 15, 2011, 03:46:05 PM »
Have not tried this yet myself, but it looks very interesting: http://www.javawa.nl/weblinkcreator_en.html

There are some examples here: http://www.javawa.nl/weblinks.html#en

Map Making Support / Converting raster landcover data to shapefiles
« on: December 23, 2010, 08:13:12 PM »
I posted elsewhere about using Filemaker Pro to process New Jersey landcover data for a project I'm working on. I want to expand this map to neighboring states, but there just isn't any high resolution landcover data available for Pennsylvania or New York. The only thing I could find was 250k historical USGS LULC from the 70's and 80's.

But the National Landcover Database has relatively high res data (30m per pixel) from 2001 in raster format where the colors correspond to codes (see: http://www.mrlc.gov/). The problem is, how to get the raster data into shapefiles without a really tedious workflow or purchasing expensive software? I found a way to do this using Mapwel, and I thought I'd post here in case it helps someone else. If you know a better way to do this, please share!

First, I downloaded the NLCD imagery from the link on the site above. I then opened the file and exported small tiles (~1500x1500 pixels) as GeoTiff files. These can be imported into Mapwel with one click.

I then used the magic wand (trace) tool and clicked on each of the different colors to vectorize them. There are several settings to play with in the magic wand control panel, and some trial and error is needed to get the best results. But after that, it's pretty straightforward - I just clicked on each of the colors in the image (there are about 16), gave them names and let the software trace the outlines. I named the areas with the hex codes of the custom types I would use later in Globalmapper.

The results were then exported as a .mp file and opened in Globalmapper to massage the data. In Globalmapper I searched for each of the names given to the polygons and assigned the correct MP_TYPE values to them. Seems like there's probably an easier way to do this, but I didn't find it.

After getting all the correct MP_TYPE's assigned, I combined the landcover with the other layers of my map, exported as a .mp file and compiled with cgpsmapper. My custom type file is the secret sauce that makes it all work in Mapsource. :)

This technique should work with any kind of raster data that uses color codes to represent values. If you just want to produce simple, green forest shading, that would be easy to do from the NLCD  since you'd only need to vector three different colors (for Deciduous, Evergreen and Mixed forest).

Mapwel also has a one-click auto-vectorizer and I played with that also. It creates a lot of polygons, and I didn't like the pixellation so much. The Magic Wand tool has a setting to create curved polygons.

I have the advanced version of Mapwel, but I believe the free download may do all of this as well. The free version won't send a fully processed map to a GPS, but it will let you save files on your computer. I'm not certain whether it allows the export of .mp files however. Regardless, you can experiment with the magic wand tool in the free version and see if it looks useful.

Here are a couple screenshots from the Nuvi 3790 along with the North America DEM file.

GPSr Units / Oregon 450 now $270 at Bass Pro
« on: November 18, 2010, 03:50:06 PM »
Lowest price we've seen on this unit since the big REI Labor Day sale at $250. Looks like a good deal on what is arguably the top handheld on the market: http://www.basspro.com/webapp/wcs/stores/servlet/Product_10151_-1_10001_10205401_425002001_425000000_425002000?cmCat=CROSSSELL_THUMBNAIL

Using The Maps/Garmin Software / Mapsource install tutorial
« on: November 04, 2010, 07:21:30 AM »
Saw this suggested elsewhere, and it sounded like a good idea. Instead of the trick of installing Training Center and then Mapsource, you could install BaseCamp first, then Mapsource. I think BaseCamp also includes the crude basemap and Mapsource should see that when installed.

This would make a little more sense IMO, since most people will find BaseCamp more useful than Training Center. I don't have a "clean" machine handy to try this on myself at the moment, but seems like it would work.

Map Making Support / Manipulating Shapefile data in FileMaker
« on: November 01, 2010, 10:00:44 AM »
When it comes to GIS data, if I can't open a file in GlobalMapper then I'm pretty clueless. So maybe somebody can set me straight on how to accomplish this. The search/replace function in Globalmapper is very powerful, but still awkward for processing large amounts of data. I am very experienced in developing databases using FileMaker Pro, so I'd like to use it to massage a large amount of Land Use/Landcover data that I have downloaded from my state's GIS website.

For example, I downloaded the following:


and ended up with these files:


I imported w07lu07.dbf into Filemaker with no problem. After massaging the data, I can easily export it back out as a .dbf file. But then what? Normally I would just load the shapefile into Globalmapper (w07lu07.shp) and discard all those other files. How do I associate the modified .dbf file with the shape data in the .shp file? I am going to add a few more fields to the database (such as a Garmin polygon type - eg: 0x50)

My goal is to be able to import a bunch of files like this, run a filemaker script to assign Garmin polygon types to each record, open the file for further editing in GlobalMapper, then export it out as an .mp file to compile in cgpsmapper.

Can somebody point me in the right direction? :)

General Discussion / GPSies
« on: October 02, 2010, 08:56:56 AM »
Hadn't seen this before. Looks like a good resource to find tracks to add trails to your maps: http://www.gpsies.com

The Find Coordinates tab seems to do a nice job. And you can choose Google/Yahoo/Microsoft/OSM map displays.

Map Making Support / Glimmer of hope for bigger "custom maps"?
« on: July 23, 2010, 09:00:28 AM »
This just appeared on Garmin's support site. I'm surprised to see that they are actually considering relaxing the size restrictions on "custom map" (raster image) format.


Quote from: TRAILTECH
We are excited about the continued interest and adoption of Garmin Custom Maps by Garmin customers.  We are evaluating the performance impact of increasing the maximum tile size and overall tile count.  If these improvements can be achieved, our limits may be raised.  However, structural differences in the file format between Garmin Custom Maps (KMZ) and Garmin BirdsEye (JNX) will prevent Custom Maps limits to ever reach the overall capacity of Garmin BirdsEye.




Map Making Support / End of cgpsmapper?
« on: June 29, 2010, 09:21:38 AM »
See: http://www.cgpsmapper.com/download/Readme0100.txt

Version 100 is expected to be the final and last version of cGPSmapper program,
no further development is expected - only bug fixes.
Support will be provided till end of 2010

Map Making Support / Limits of the .mp and .img formats
« on: June 28, 2010, 10:12:48 AM »
I have been working on a personal project to map the little trails on my land, and learned something in the process which might be of interest. Many of you have read the tutorial here, specifically the comments on page 23 about map resolution: http://cgpsmapper.com/download/GM8DocV2.pdf

‘24’ refers to the precision of the latitude and longitude coordinates provided for the object. When declaring the location of objects in the world, the highest precision available uses 24 bits of resolution, which resolves to an accuracy of about 2.5 meters. Consumer GPS units have a best-case accuracy of about 8 meters.

In another thread here, somebody questioned the math that lead to the 2.5 meter figure. I am not sure how the calculation was performed, but the following screenshot will graphically demonstrate it. Using GlobalMapper, 1 foot per pixel aerial imagery, and track points accumlated from many walks on my little trails, I created my map. The points on the polylines are quite close together in some cases - one or two feet apart. I exported the map as a .mp file and then opened it in GlobalMapper again, overlaid on the original. In the image below, the pink lines are the original and the blue lines are the .mp file.

So you can see that the actual coordinates have been rounded off to 24 bit numbers, creating stair steps. Right away it became obvious that I wouldn't be able to make the kind of map I wanted using Garmin's vector format. Now granted, this detail is beyond the accuracy I can expect from my Oregon anyway... but I still wanted to make my map!

The solution was simple; I created a "custom map" (raster image) as a .kmz file. I had overlaid my vector data on 1 foot per pixel aerial imagery, so I just exported everything as a .kmz file in the proper format for the Oregon. But the results still weren't quite what I had hoped for. At close zoom settings, the lines looked too jaggy. So I re-sampled everything at 4 inches per pixel and exported again. This produced a very nice looking map with smooth lines even at extreme zoom levels.

You may not ever want to create a map at this resolution, but if you do then it's nice to know that the 2.5m/24 bit limit does not apply to "custom maps". Of course, you will need an Oregon, Dakota, Colorado, GPSMap 78 or 62 to use this kind of map.

GPSr Units / "Map Themes" on Nuvi 3700 series
« on: June 24, 2010, 06:06:33 PM »
The new 3700 series Nuvi's have a menu for "map themes" which evidently allows you to pick different color schemes. I wonder how this is being implemented? One simple way would be to allow a choice of different .typ files within the mapset.

GPSr Units / New 3700 series Nuvi's from Garmin
« on: April 19, 2010, 10:46:57 AM »
A pretty obvious attempt to copy the iPhone design, but these new models look pretty interesting. They have finally done one thing I've been hoping for - the unit has an accelerometer and switches automatically between landscape and portrait modes (like.... an iPhone :D). This could really help make the same unit better suited to handheld and automotive use. And it's funny, because one of their earliest models, the GPS V, could switch between landscape and and portrait modes back in the 1990's.

But based on my experiences with the Nuvi 1350 (one of their most recent models), topo maps may not fare so well. I guess we will need to wait a few months to find out....


General Discussion / Where did cgpsmapper go?
« on: March 11, 2010, 07:15:20 PM »
Just now I got the following:

Address Not Found
Firefox can't find the server at www.cgpsmapper.com.
The browser could not find the host server for the provided address.

Just a glitch, or something else?

Pages: 1 2 3 [4] 5