[talk-ph] OSM-PH Garmin Map Hackday Feb 18, 2011

maning sambale emmanuel.sambale at gmail.com
Mon Feb 28 12:17:10 GMT 2011


A synopsis of the discussion during the hackday.  @ eugene, rally, rem
and jc, please add anything I missed.


The OSMPHGPS project was started by Maning 3 years ago (Jan 2008) as a
demonstration of what the OSM data can offer to the pinoy mapping
community.  Personally, I created the garmin maps because I own a
garmin device and saw the oppurtunity to recruit mappers for OSM.

On the recruitment front, I'm proud to say that the garmin map did in
fact able to solicit contributions from garmin users.

Recognizing this contribution to OSM as a whole, it was decided that
the project should continue not as my personal project but more as a
community resource where everyone can contribute and improve upon.

In the words of Eugene, "I think the OSMPH community as a whole has a
stake in the OSMPH Garmin Map to make it the best "product" of the

Hence, from hereon, the osmphgps is now an OSMPH Org project.  In the
coming weeks/months we will start to move the download links from my
personal wepspace to the org website (http://openstreetmap.org.ph).

In a way, this helps promote our local chapter as well.

Part of the plan is to involve other community members in the
compilation of the map.  At the moment, two (rally and maning) are
directly involved.  We need more people to participate, this is the
prime reason of organizing the hackday last Feb 18, 2010.  During the
discussions, we tackled several components of the map compilation and
outlined some further development points.  No actual code was
committed that night but I think we have outlined a good framework in
the future development of the garmin maps.

Highlights of the discussion are as follows:

OSM-PH Garmin Map Hackday Feb 18, 2011
People attended:  maning, eugene, rally, rem, jayzee

Map compilation process
 - All existing code (styles, typs and build scripts) are available in
 github (http://github.com/maning/osmphgps). Thus anyone, can
 fork/clone the repo; customize the styles and; contribute back your
modifications to be included in the main map.

 - The current map is now ~25 MB (and is continuously growing), thus,
older   garmin devices cannot use our map anymore.  We plan to create
a   generic script so that other garmin users can create   smaller
maps that will fit older device' storage capacity.

 - further work are needed on our routing algorithm, it  works for
most cases, but we need to document edge cases particularly
 speed calculations and road class in order to fit them with the PH
traffic  condition. Rally is doing some tests on this end and it would
be very  helpful if you (garmin users) can report odd cases of routing

City and Street Search
 - Last week we started the public distribution of the map with City
and street search.  In some of my tests, it works, but, lack the
robustness of other  garmin maps.  Sample case: A street is assigned
to a single place/"city" depending on the location of the place node.
For  example, "Street x Y village, Z City" can be found either in in X
or Y and not both.  The problem is that if there are many
place=village or hamlet tags within a City, very few results will come
out when using the actual city name.

This problem is due to mkgmap's dependence to the is_in tags.  A
better solution in the long run is to use the admin_level polygons in
order to assign cities on streets within the admin polygons.  The
mkgmap devs are aware of this problem and  they are developing a
solution to address it.

On the mapping side, we encourage you to continue adding admin
boundaries so that we can use that data later on.

POI audit
 - Many POIs are still not included in the garmin map.  If you feel a
certain POI is important for the gps map let us know.

On creating custom maps
 - it has been discussed in the talk list on developing custom maps
for specific user-groups for starters, we will create a generic
outdoor map suited for hikers, MTBers and general outdoor activities.
If you have ideas on the design let us know.

Using osm.org.ph infrastructure
 - In the coming weeks/months download and Q/A forum related to the
osmphgps map will be migrated to the osm.org.ph domain.  An important
note here is that the Q/A forum will be used specifically to general
inquiries regarding the garmin map.  All mapping related discussions
should be in the talk-ph list.

All for now.  For any ideas don't hesitate to post them in the list.

"Freedom is still the most radical idea of all" -N.Branden
wiki: http://esambale.wikispaces.com/
blog: http://epsg4253.wordpress.com/

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