[talk-ph] request for testing 10m contour for garmin (was Re: Groundtruth.)

Rally de Leon ralleon at gmail.com
Fri Jul 30 07:18:20 BST 2010

Groundtruth (contour) runs on my mapsource. I initially loaded 6 tiles
(from east to west -- Quezon sierra madre, Rizal to Batangas, NCR to
Bataan) on my 76CSx, together with the latest osmph_garmin. They show
on top of each other (transparent). Didn't crash on my garmin.

However, with the low-res screen of 76CSx (Details set to Normal), the
contours on the mountain portion is only usable (readable) at
zoomscale 2km & below. At 3km above, the 100m contour lines tends to
clutter the mountainous portion of the map (fortunately there aren't
many roads & POI's there).

Redraw speed was ok. I didn't notice any problem (on normal
street-level zoom), but I'm doing only around 30kmh, coz i'm also
collecting tracks at that time. But on 'over zoom mode' (12-20meters
scale), redraw speed slows down a bit, but still acceptable (while
driving); Although this will not be an issue at walking-pace of
mountain-hiking gps users. I don't know what will happen if I load the
entire groundtruth map (around 180mb) together with osmphgarmin map.
let's see later if my unit will crash :-)

Accuracy Test:
76CSx with External Antenna on top of car (roughly 1-1/2 meter above ground)
GPS signal availability & strength was very good (EPE alternating
between 2 to 4 meters)
On initial test on Antipolo Hills this morning (an area above
120meters elevation), I parked my car exactly on top of a few
10m-contour lines that I crossed along the road, and compared their
Elevations with the readings of Barometric Sensor Elevation of 76CSx.
Not bad !!! (there's only 3-5 meters difference, sometimes exactly the
same like on the 10meter contour lines).

Well, considering other factors like height/location of antenna on top
of my car & low EPE of gps, initial test says we can possibly navigate
in zero-visibility mountain area (using STRM 10meter contour data)
with lesser chance of falling of a cliff.

I wish other people can test this (STRM data) map on other higher
areas to verify my findings (if high-accuracy is same on other

On Wed, Jul 28, 2010 at 8:31 PM, maning sambale
<emmanuel.sambale at gmail.com> wrote:
> Anyone interested to test this?
> 10m contour interval for Garmin devices.  Download the link below (~200 MB):
> http://dl.dropbox.com/u/607635/osm-ph_gps_maps/10mcontour_ph_winmapsource_latest.exe
> The contour were generated from SRTM data using Groundtruth.  The data
> was divided into 0.75 grid tile.
> Beware: Loading the full Philippine map crashed my device!  Please
> test if this works for your own device.
> I am interested in the following scenarios:
> 1.  If you only add a limited number of contour tiles, does it crash your unit?
> 2.  If you add only the contour and not the osm-ph map, does it crash as well?
> 3. At what zoom level does it crash (watch the map scale)?
> Enjoy!
> On Tue, Jul 27, 2010 at 11:41 AM, maning sambale
> <emmanuel.sambale at gmail.com> wrote:
>> Last time I checked, groudtruth uses the cgpsmapper to compile garmin
>> maps.  The free cgpsmapper has a lot of limitations (i.e. limited
>> routing), unless you but the pro version.  However, I used groundtruth
>> to generate contour maps based on SRTM.  I intend to provide free
>> download soon.  If anyone wants them for testing, let me know.  My
>> unit crashed when I loaded the whole country's 10m elevation contour!
>> On Tue, Jul 27, 2010 at 12:47 AM, Eugene Alvin Villar <seav80 at gmail.com> wrote:
>>> Here's the original blog post (Dec. '08) by Ground Truth's creator about the
>>> difference between his tool and the popular mkgmap tool, which maning uses
>>> to create the OSM-PH Garmin maps.
>>> http://igorbrejc.net/openstreetmap/groundtruth-a-new-garmin-mapmaking-tool
>>> Take note that the post is back in 2008. Things probably changed a lot since
>>> then.
>>> On Mon, Jul 26, 2010 at 7:59 PM, Jim Morgan <jim at datalude.com> wrote:
>>>> Just found this tool for making Garmin images from OSM data
>>>>        GroundTruth v1.0.0.0 by Igor Brejc
>>>>        Generates Garmin maps from OpenStreetMap data
>>>>        Visit http://wiki.openstreetmap.org/wiki/GroundTruth for more info
>>>> Also a helpful step-by-step guide.
>>>>        http://wiki.openstreetmap.org/wiki/GroundTruth_For_Dummies
>>>> I don't have a Garmin. But I thought it might be useful. Looks quite
>>>> customisable as well. You can make eg a hiking map using a different set of
>>>> rules.
>>>>        groundtruth makemap
>>>> -rules="http://wiki.openstreetmap.org/wiki/GroundTruth_Hiking_Map"
>>>> Jim
>>>> --
>>>>   datalude: information security
>>>>   e: jim at datalude.com
>>>>   Philippines: +63 2 403 1311 / mob: +63 920 912 5830
>>>>   Hong Kong: +852 6840 6693
>>>>   w: http://www.datalude.com/
>>>> _______________________________________________
>>>> talk-ph mailing list
>>>> talk-ph at openstreetmap.org
>>>> http://lists.openstreetmap.org/listinfo/talk-ph
>>> --
>>> http://vaes9.codedgraphic.com
>>> _______________________________________________
>>> talk-ph mailing list
>>> talk-ph at openstreetmap.org
>>> http://lists.openstreetmap.org/listinfo/talk-ph
>> --
>> cheers,
>> maning
>> ------------------------------------------------------
>> "Freedom is still the most radical idea of all" -N.Branden
>> wiki: http://esambale.wikispaces.com/
>> blog: http://epsg4253.wordpress.com/
>> ------------------------------------------------------
> --
> cheers,
> maning
> ------------------------------------------------------
> "Freedom is still the most radical idea of all" -N.Branden
> wiki: http://esambale.wikispaces.com/
> blog: http://epsg4253.wordpress.com/
> ------------------------------------------------------
> _______________________________________________
> talk-ph mailing list
> talk-ph at openstreetmap.org
> http://lists.openstreetmap.org/listinfo/talk-ph

More information about the talk-ph mailing list