Skip to content

BD TOPO / Garmin Mappings

This page documents how IGN BD TOPO layers are transposed into Garmin types in the mpforge pipeline.


BD TOPO themes used

Transport

BD TOPO layer Garmin type Description
TRONCON_DE_ROUTE (motorway) POLYLINE 0x0001 Motorway
TRONCON_DE_ROUTE (national) POLYLINE 0x0002 National road
TRONCON_DE_ROUTE (departmental) POLYLINE 0x0003 Departmental road
TRONCON_DE_ROUTE (municipal) POLYLINE 0x0006 Residential street
TRONCON_DE_ROUTE (track) POLYLINE 0x000A Unpaved track
TRONCON_DE_ROUTE (path) POLYLINE 0x000E Trail / footpath
TRONCON_DE_VOIE_FERREE POLYLINE 0x0014 Railway

Hydrography

BD TOPO layer Garmin type Description
TRONCON_HYDROGRAPHIQUE POLYLINE 0x001A Watercourse (line)
SURFACE_HYDROGRAPHIQUE POLYGON 0x0028 Water body (surface)

Vegetation

BD TOPO layer Garmin type Description
ZONE_DE_VEGETATION (forest) POLYGON 0x0050 Forest / woodland
ZONE_DE_VEGETATION (orchard) POLYGON 0x0051 Orchard / vineyard
ZONE_DE_VEGETATION (meadow) POLYGON 0x0052 Meadow

Buildings

BD TOPO layer Garmin type Description
CONSTRUCTION_SURFACIQUE POLYGON 0x0013 Building footprint

Toponymy

BD TOPO layer Garmin type Description
LIEU_DIT_NON_HABITE POI 0x6400+ Locality, summit, pass
COMMUNE POI 0x0400+ Municipal seat

Simplification profiles by layer

mpforge applies multi-level simplification profiles to BD TOPO layers via the catalog pipeline/configs/ign-bdtopo/generalize-profiles.yaml. Each feature can carry multiple geometries (Data0= detailed, Data2= for medium zoom), selected by imgforge at render time. Douglas-Peucker tolerances in WGS84 degrees.

BD TOPO layer Profile Data0 (detailed) Data2 (medium zoom) Rationale
BATIMENT none raw (no DP) Geometry preserved as delivered by IGN
TRONCON_HYDROGRAPHIQUE mono-level simplify: 0.00005 (~5 m) simplify: 0.00020 (~22 m) Detailed watercourses + medium zoom version
ZONE_DE_VEGETATION mono-level + Chaikin Chaikin 1× + simplify: 0.00005 simplify: 0.00020 Natural smoothing of contours
TRONCON_DE_ROUTE (Motorway, National) dispatch when: CL_ADMIN simplify: 0.00001 (~1 m) simplify: 0.00008 Maximum routing preservation
TRONCON_DE_ROUTE (Departmental) dispatch when: CL_ADMIN simplify: 0.00003 simplify: 0.00010 Detail/size balance
TRONCON_DE_ROUTE (Municipal, Other) dispatch when: CL_ADMIN simplify: 0.00005 simplify: 0.00015 Reasonable defaults
TRONCON_DE_ROUTE (Track, Path) dispatch when: CL_ADMIN simplify: 0.00010 simplify: 0.00030 More aggressive simplification
TRONCON_DE_ROUTE (other) fallback levels default simplify: 0.00005 simplify: 0.00015 Unknown CL_ADMIN
COURBE mono-level simplify: 0.00008 simplify: 0.00025 Contour lines

Constraints: any routable layer (TRONCON_DE_ROUTE) must declare n: 0 on each branch (routing guarantee). Tolerances n: 0 for routable classes are capped at ≤ 0.00010° (~11 m) to preserve connectivity at intersections.

See Step 2 — Multi-level profiles for the YAML semantics.

Categorization rules

The mappings between BD TOPO attributes and Garmin type codes are defined in the pipeline's YAML configuration files. The field mapping (bdtopo-mapping.yaml) bridges BD TOPO column names to standard Polish Map fields.

Transposition example

A road in BD TOPO:

Layer: TRONCON_DE_ROUTE
IMPORTANCE attribute: 2
NATURE attribute: Route à 2 chaussées
Name: Route Nationale 7

Becomes in the .mp file (after field mapping):

[POLYLINE]
Type=0x0002
Label=Route Nationale 7
Levels=0-2
RouteParam=4,3,0,0,0,0,0,0,0,0,0,0
Data0=(45.1234,5.6789),(45.1235,5.6790),...
[END]

OSM / Garmin mappings

OpenStreetMap data is a complementary source to BD TOPO for POIs and natural features.

Amenity (24 types)

OSM tag Garmin type Description
amenity=bar POI 0x15200 Bar
amenity=biergarten POI 0x15201 Beer garden
amenity=cafe POI 0x15202 Café
amenity=fast_food POI 0x15203 Fast food
amenity=restaurant / food_court POI 0x15204 Restaurant
amenity=ice_cream POI 0x15205 Ice cream shop
amenity=pub POI 0x15206 Pub
amenity=library POI 0x15207 Library
amenity=bicycle_parking POI 0x15208 Bicycle parking
amenity=bicycle_repair_station POI 0x15209 Bicycle repair station
amenity=fuel POI 0x1520a Fuel station
amenity=charging_station POI 0x1520b Charging station
amenity=motorcycle_parking POI 0x1520c Motorcycle parking
amenity=parking POI 0x1520d Parking
amenity=taxi POI 0x1520e Taxi stand
amenity=clinic / doctors POI 0x1520f Doctor / clinic
amenity=dentist POI 0x15210 Dentist
amenity=hospital POI 0x15211 Hospital
amenity=pharmacy POI 0x15212 Pharmacy
amenity=veterinary POI 0x15213 Veterinary
amenity=shelter POI 0x15214 Shelter
amenity=toilets POI 0x15215 Toilets
amenity=* (default) POI 0x15216 Other amenity

Shop (53 types — selection)

OSM tag Garmin type Description
shop=bakery POI 0x15001 Bakery
shop=supermarket POI 0x15006 Supermarket
shop=convenience POI 0x15004 Convenience store
shop=butcher POI 0x15007 Butcher
shop=hairdresser POI 0x15002 Hairdresser
shop=pharmacy (via amenity=pharmacy)
shop=* (default) POI 0x1500e Other shop

The complete 53 shop types are defined in garmin-rules.yaml. Types sharing the same Garmin code are grouped with the in: operator.

Natural

OSM tag Geometry Garmin type Description
natural=ridge LINE POLYLINE 0x11a00 Ridge
natural=arete LINE POLYLINE 0x11a00 Arete
natural=cliff LINE POLYLINE 0x11a01 Cliff
natural=cave_entrance POINT POI 0x15301 Cave entrance
natural=rock POINT POI 0x06614 Rock
natural=sinkhole POINT POI 0x11509 Sinkhole
natural=cave (default) POINT POI 0x15300 Cave

Tourism

OSM tag Garmin type Description
tourism=viewpoint POI 0x16 Viewpoint (Scenic Area)

Layers not yet integrated

Some BD TOPO layers are not yet integrated in the pipeline:

Layer Reason
High-voltage power network No appropriate standard Garmin type
Detailed regulated zones Attribute complexity
Fine administrative boundaries Redundancy with cadastral data

Contour lines and DEM: do not confuse

Contour lines (isolines at 10 m intervals) are vector data from IGN altimetric layers. They are integrated into the pipeline like any other data source via the mpforge YAML configuration.

DEM (IGN BDAltiv2 or NASA SRTM) is a raster digital terrain model, used by imgforge (--dem) for hill shading and elevation profiles on the GPS. These are two complementary but distinct datasets.

Comments

Comments are managed by Comentario, self-hosted at comentario.allfabox.fr. Posting a comment may set a session cookie.

Fund a summit