Reference3D
Highly accurate 3D products covering vast areas
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The constitution of the Reference3D database began in 2002, with the
launch of SPOT 5, with an annual production rate of 7 million km².
Reference3D is a geocoded, worldwide data base, made up of 3 information
layers:
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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: 15 m @ 90%
HRS orthoimages
These images are orthorectified from the DEM and have a high degree of geometric quality and location accuracy
- Absolute altimetric accuracy: 16 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.
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