[[TOC]]
= Share GPS Data =

== Problem Description ==
 * Field staff for NGOs (both Humanitarian & Development) visit Programme sites with handheld GPS (e.g. Garmin eTrex).
 * They collect data as they go (Tracks & Waypoints).
 * They would like a way of easily sharing this information between each other:
  - uploading data to a central repository
  - managing this master repository to have a reference dataset: no duplicates, names checked for consistency
   - this management should work offline
  - download the reference dataset to each GPS
 * A secondary benefit will be in terms of wider communications (e.g. reporting to Donors)
 * A potential future enhancement would be to be able to download GPX routes from/to specific locations.

This requirement is defined by [http://oxfam.org Oxfam] in Haiti, but is applicable to many other organisations & locations.

== High-Level Architecture Proposal ==
It would be ideal if as much of the reference dataset as possible could be incorporated into the Base Map - !OpenStreetMap is ideal for this.

Propose to:
 * Set up a Virtual Machine containing all necessary software (to make it easy to install on any available PC - this setup may need replicating in several offices, although no need to sync between offices except via main !OpenStreetMap database at this time)
 * Local OSM Server
 * Build a GUI within Sahana to allow the uploading/editing of GPX data

=== Other Options Considered ===
 * Garmin !MapSource
  - can't load more than 1 GPX file at a time
 * Google Earth
  - doesn't work offline

== Detailed Architecture Proposal ==
=== Sahana ===
The current GPX layer interface is probably insufficient.

Instead have 2 tables:
 * WayPoints (where each point is individually editable for a label & marker - often the raw data will just have numeric labels, so we'll need to add a prefix to distinguish for when re-labelling from written notes)
 * Tracks (where all points are equal - we don't need to keep track of time or person: if we wish to see a specific track we can use the current GPX file interface for that...so maybe we keep the file uploads but add to the main table via an onaccept?)

Can we develop a Flash(?) interface to actually manage the transfer to/from the unit of the GPX &/or basemap?

=== Local OSM Server ===
 * wiki:InstallationGuidelinesGISDataLinux#OpenStreetMap

=== Edit Base Map ===
 * Potlatch2
  * Editing local database or only main one?
  * Need better integration into Sahana:
   * passing in the area of the current viewport
   * seeing Sahana overlays inside Potlatch (can export as either GPX or OSM)

=== Sync Base Map ===
Our local install needs to be kept up to date from the global repo.

If we're making local edits then we need to feed those back to the master repo.
 * This may be hard. Team up with [http://dev.ifs.hsr.ch/osminabox/ OSM-in-a-Box] to look at this?

=== Export to Base Map ===
 * wiki:UserGuidelinesGISDataOpenStreetMapGarmin
  * srtm2osm 
  * mkgmap

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[wiki:BluePrintGeographicInformationSystems GIS BluePrints]