[[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 as evidenced by this combined Problem Definition for RHoK:
 * http://wiki.rhok.org/Sahana_Eden_Offline_Mapping

It could also be the public version of the WFP !GeoPortal (which will be separate from their Intranet):
 * http://geoportal.logcluster.org

== 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
  - allows access to simple, known tools for manipulating the Waypoints to download an authoritative GPX
  - treat the basemap as more static (do an initial 1-time basemap inc contours & follow this up with a process for updating the contours.osm with Osmosis)
  - doesn't work offline, although could use a KML super-overlay when offline:
   * http://svn.openstreetmap.org/applications/utils/wms2kml/
   * !GeoServer can produce the !SuperOverlay from cascaded WMS:
    * http://geoserver.org/display/GEOS/GSIP+47+-+WMS+cascading
    * http://docs.geoserver.org/stable/en/user/googleearth/index.html
   * [http://wiki.openstreetmap.org/wiki/Mod_mapnik_wms mod_mapnik_wms] to create the WMS
 * [http://depiction.com Depiction]
  * Data primarily only shareable with other Depiction users which means hard to gain traction even within an organisation let alone for interagency work.
  * Installation requires admin rights on the PC, which many field staff won't easily have access to - again lowering the ability to get wider adoption.
  * Can't create new Depictions or use BaseMaps at all without an active Internet connection.
  * Revealers seem very gimmicky: I don't find them useful & they're really hard to use in practise (I just wanted a 'full-screen option').
   * GeoExplorer already has the ability to dynamically edit layer opacity, which is the 1 thing I'd use them for.
  * Licensing costs push this beyond local partners to whom we want to handover the tools when moving from Response -> Recovery -> Mitigation/Preparedness (USD 200/machine + add-ons, such as $50 just for icons that come free with Sahana!)
  * No support for KML (or GeoRSS)
  * No ability to edit the OpenStreetMap base layer which adds so much value to these maps
  * Adding Elevation data is clumsy (fairly easy to make this 'seamless' ;) )

== 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?)
  * http://www.postgresonline.com/journal/index.php?/archives/116-Loading-and-Processing-GPX-XML-files--using-PostgreSQL.html

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

Extend our [wiki:BluePrintGISGeoExplorer GeoExplorer] integration as the basis for this (adding other missing !MapViewingClient functionality as we go).
==== Ideas from Depiction ====
[http://depiction.com Depiction] has some useful functionality with some nice UI ideas...there are videos which can be downloaded to review.
 * Simple UI
  * add new Features to the map via the mouse inc Single/Multiple options
  * !QuickAdd toolbar for common resources
  * Manage Elements tool to locate features within viewport (category, tags or name) & edit their properties (global type or individual)
   * Colour picker
   * Label
   * Icon (Image/Size)
 * Modelling
  * elevation data within the database
   * can we use the same datamodel as for Mapnik's contours?
   * add an easy downloader like srtm2osm
  * models could come from GRASS or R, maybe via WPS?
   * Plumes: Wind speed, direction, volume
   * Flood
   * Liquid flow
   * Antennas (do we need this within Sahana?)
 * Routing
  * road structure within the database
   * imports from !OpenStreetMap
   * imports from Shapefiles
   * [http://www.pgrouting.org pgRouting] for back-end calculations?
   * build on Measure tool (if no better ones available) for front-end UI?
 * !GeoReferencing
  * integrate one of the existing tools: [wiki:BluePrintGISRectifier]
 * Shapefiles support
  * integrate OGR2OGR (usable even with basic sqlite versions) - e.g. [http://ogre.adc4gis.com Ogre]
  * !GeoServer via REST? (-> PostGIS where available)
 * Permatext (useful for printing, especially)
 * Draggable property (default based on resource type?)
 * Interactions
  * Zones of Influence
   * Barriers are polygons
    * Default to octagon
    * Can create custom polygons by dragging/adding/removing polygons (UI for this already in OpenLayers)
   * Calculated (e.g. Plumes/security cameras)
=== 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:
 * [http://wiki.openstreetmap.org/wiki/Osmosis Osmosis]
 * [http://dev.ifs.hsr.ch/osminabox/ osm2gis]

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?
 * [http://wiki.openstreetmap.org/wiki/Things_To_Do#Task:_Satellite_Instances Discussion in OSM Wiki]

=== Export to Base Map ===
 * [wiki:UserGuidelinesGISDataOpenStreetMapGarmin]
  * [http://wiki.openstreetmap.org/wiki/Srtm2Osm srtm2osm] (only needs to be run once per location - e.g. country, so can be done outside VM in Windows)
  * [http://www.mkgmap.org.uk/ mkgmap]

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[wiki:BluePrintGeographicInformationSystems GIS BluePrints]