Reference3D®: your geographic reference system

DEM + Ortho layer + Quality Information

Developed in partnership by Spot Image and the French survey and mapping agency IGN, Reference3D is a geocoded database containing three layers of information:

a DTED level 2 HRS DEM
GPS-compatible HRS Orthoimage
quality and traceability metadata

Reference3D is the keystone of any application that calls for very-high-accuracy elevation data.
Reference3D is unrivalled in the world for accuracy, coverage, with 58 million km² already covered.

An unlimited source of ground control points Reference3D orthoimages provide ground control points accurate enough to ensure GPS compatibility: 10mCE90 or 7mRMS

They can be used to orthorectify imagery from most Earth observation satellites (SPOT, FORMOSAT-2, Kompsat-2, TerraSAR-X, WorldView1, GeoEye, QuickBird, Ikonos, Landsat, Radarsat, Envisat, etc...) when positional data are not available.

DEM

These files contain a uniform grid of terrain elevation values of an area of interest and are obtained through automatic correlation of SPOT HRS stereopairs.

Sampling step: 1 second of arc (~ 30 m at the equator, varying according to latitude)
Absolute elevation accuracy: 10 m @ 90% for a slope < 20°
Absolute planimetric accuracy: 10 m @ 90%

HRS orthoimages

These images are orthorectified from the DEM and have a high degree of geometric quality and location accuracy

Absolute planimetric accuracy: 10 m @ 90%
Sampling step: 1/6 second of arc (~ 5 m at the equator - varying according to latitude)

Quality and traceability data

These are quality indicators for data sources and provide references and footprints for DEMs and orthoimages,
They describe the processing done for producing DEMs (masks),
They give accuracy estimates.

Size

Reference3D comes in geographic tiles of 1°x 1° covering emerged land areas and aligned along parallels and meridians.

The surface area of a tile, equivalent to 111 km x 111 km at the equator, decreases as the latitude increases.

Format / Delivery

Reference3D comes in a DIMAP format.
The HRS DEM complies with the specifications for the level 2 DTED format.

Quick turnaround:

Few hours delivery for the 58 million km² already available
product covering approx. 500,000 km² ready in 3 months.

Perfect data consistency

Reference3D provides finely detailed information and close registration of data layers for:

rigorous matching of map data, for example in the oil industry
building onboard databases for UAVs, missiles and aircraft, and for mission planning, well suited to defence ministries and armament manufacturers
compiling or updating maps
checking existing databases