EuroSDR Projects - Host Ireland

7. What is the average time difference of the time of the acquisition of the primary data from
which the road data is generated to the time of road data acquisition? E.g., road data
acquired in 2001 from aerial imagery flown in 1998 would have a time difference of 3 years.
3 to 6 months
8. What is the average age of the road data compared to now?
E.g., for 2002 and the above example, it would be 4 years.
about 1 year
9. Roads are extracted as:
road edges or directly as road centerlines including width?
10. Is height information included? yes no
If yes, how is height determined?
Directly measured, e.g., in stereo images
Derived from DTM
Derived from DSM
11. Estimated geometric accuracy
Planimetry:
Mean error 1 m RMS error 1 m Maximum absolute error < 3 m
Height (if applicable):
Mean error – RMS error – Maximum absolute error
How are the above accuracy measures derived? E.g., from sample statistics using reference
data, based on experience, etc.
estimated, based on experience
12. List below all additional information (attributes) derived, e.g., road class, number of
lanes, road width, surface material, etc. For geometric attributes, e.g., road width, give the
geometric accuracy with which this attributes are extracted and specify what the accuracy
measures represent, e.g., RMS. For each attribute give its importance from a
user/application point of view as low, medium, high.
road class (high), number of lanes (high), road width (high)
13. Is the road data topologically connected? yes no
If yes, how is the topology established?
Automatically
Manually through post-editing
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