Technical aspects of data acquisition and display
Conclusion
Dunes, beaches and inter-tidal zones are particularly difficult to survey
and therefore elevation data are difficult to acquire. Since laser scanning
has reached an operational level, this new remote sensing technique has
been able to provide an alternative to elevation acquisition of coastal
zones areas. Laser scan technique is characterized by a high density and
high accuracy of elevation information. As it is an airborne technique,
data can be quickly acquired and few ground measurements are needed.
Because of these characteristics, laser scanning is particularly adapted
to generate DTMs of coastal zone areas.
Using a new technique is always a challenge. In the first undertaken
projects as those presented in this article, it has not been easy to specify
the suitable point density neither formulate conditions under which
the survey should be performed in order to reach the aimed accuracy.
These last six years of experience have helped to clarify these issues. The
undertaken projects has enabled to determine the suitable number of
reference areas, the maximum distance between the ground GPS station
and the plane as well as the most suitable number of transversal strips.
Large efforts have been invested in order to develop suitable software
to process the data and define methods and tools to control the quality
of the DTMs generated. In six years time the hardware specifications have
increased enabling to acquire higher scanned point density and to minimise flying time. Constant progresses are being done and the reliability of the laser scan technique is growing. The results obtained in the
field of coastal zone management has led the Survey Department to use
laser scan technique to generate a DEM of the whole Netherlands with a
point density between one per 16 m
2 to one per square metre in certain
areas (Huising & Vaessen, 1997a). This last project shows the importance that laser scanning is getting in elevation data acquisition in the
Netherlands.
Bibliographic references
Ackermann F., 1997. Airborne laser scanning - A brief status review.
Barichenko S. & Reuter R. (eds), 3
rd EARSeL workshop on lidar
remote sensing of land and sea, Estonia, 85-88.
Flood M., Gutelius B., 1997. Commercial implications of topographic
terrain mapping using scanning airborne laser radar. Photogr. Eng.
Remote Sensing, 6.3(14), 327-329, 363-366.
Han C.S., 1995. Vliegtuig-laserscanning een onderzoek naar de toepasbaarheid van een moderne remote sensing inwinningstechniek
vooe het meten van digitale terreinmodellen in NGT. Geodesia, 2,
89-93.
157
Conclusion
Dunes, beaches and inter-tidal zones are particularly difficult to survey
and therefore elevation data are difficult to acquire. Since laser scanning
has reached an operational level, this new remote sensing technique has
been able to provide an alternative to elevation acquisition of coastal
zones areas. Laser scan technique is characterized by a high density and
high accuracy of elevation information. As it is an airborne technique,
data can be quickly acquired and few ground measurements are needed.
Because of these characteristics, laser scanning is particularly adapted
to generate DTMs of coastal zone areas.
Using a new technique is always a challenge. In the first undertaken
projects as those presented in this article, it has not been easy to specify
the suitable point density neither formulate conditions under which
the survey should be performed in order to reach the aimed accuracy.
These last six years of experience have helped to clarify these issues. The
undertaken projects has enabled to determine the suitable number of
reference areas, the maximum distance between the ground GPS station
and the plane as well as the most suitable number of transversal strips.
Large efforts have been invested in order to develop suitable software
to process the data and define methods and tools to control the quality
of the DTMs generated. In six years time the hardware specifications have
increased enabling to acquire higher scanned point density and to minimise flying time. Constant progresses are being done and the reliability of the laser scan technique is growing. The results obtained in the
field of coastal zone management has led the Survey Department to use
laser scan technique to generate a DEM of the whole Netherlands with a
point density between one per 16 m
2 to one per square metre in certain
areas (Huising & Vaessen, 1997a). This last project shows the importance that laser scanning is getting in elevation data acquisition in the
Netherlands.
Bibliographic references
Ackermann F., 1997. Airborne laser scanning - A brief status review.
Barichenko S. & Reuter R. (eds), 3
rd EARSeL workshop on lidar
remote sensing of land and sea, Estonia, 85-88.
Flood M., Gutelius B., 1997. Commercial implications of topographic
terrain mapping using scanning airborne laser radar. Photogr. Eng.
Remote Sensing, 6.3(14), 327-329, 363-366.
Han C.S., 1995. Vliegtuig-laserscanning een onderzoek naar de toepasbaarheid van een moderne remote sensing inwinningstechniek
vooe het meten van digitale terreinmodellen in NGT. Geodesia, 2,
89-93.
157