FUSION AND OPTIMIZATION OF LIDAR AND PHOTOGRAMMETRIC
TECHNOLOGIES AND METHODOLOGIES FOR CARTOGRAPHIC PRODUCTION
A. Diez a *, A. Arozarena b , S. Ormeno a , J. Aguirre a , R. Rodriguez a , A. Saenz a
a GFYT, Research Group “Photogrammetry and Remote Sensing”, UPM, Technical University of Madrid, 28031,
Madrid - (fotolidar@teatgis.com)
b IGN, National Geographic Institute, 28003, Madrid - (aarozarena@fomento.es)
WG 1/2 - SAR and LIDAR Systems
KEY WORDS: Multi-spectral remote sensing, Laser Scanning (LIDAR), Classification, DTM, Digital Photogrammetry, Fusion,
Change Detection
ABSTRACT:
The main objectives of this work include the combination of data acquired by photogrammetric techniques and LIDAR. It also
considers the development of some classification algorithm based on the use of spectral variables and spatial relationships aimed to
obtain the required elements for digital mapping and digital elevation model products. At the same time, the different errors
associated to the different cartographic stages are quantified. All these studies will be the basis to set up the technical requirement
paper to be considered in any LIDAR project.
1. INTRODUCTION 2. PHOTOGRAMMETRY VS LIDAR
The emergence of different airborne sensors for geospatial data
capture has allowed working with different methodologies in
cartographic production. For this reason, it is necessary to study
the feasibility of the modem technologies and their operative
development in order to achieve the optimized integration of
geospatial data.
Every technological advance is an essential step to fulfil the
needs of society, at the same time being important that the
technicians responsible indicate the means of improving results
in consideration of the different user capabilities. In this process
the national cartographic institutions must give their
professional advice and establish the working patterns
normalizing the cartographic production criteria, so as to honour
the purpose demanded by society.
The current potential in cartographic production for information
registration depends on the choice of passive sensors such as
analogical cameras and matrix or linear array digital cameras;
active sensors such as LIDAR and RADAR; information
sources such as RGB, Panchromatic, near IR, intensity level,
position (x, y) and height first echo ... last echo); sensor
orientation through INS/GPS and/or aerotriangulation;
advantage out of the information (cartography, DTM, DSM, etc.)
through photogrammetric techniques, LIDAR or RADAR.
In short, the production framework will depend on the available
means and on the technical specifications set up for carrying out
the work. We should take into account that the above-mentioned
options - in addition to the traditional ones - allow the
integration of information from the different sensors and its
subsequent management in order to achieve the intended
objective. This will be the subject of this paper along with
decision taking and the pertinent quality control, as well as the
exploitation of the information through the detection of changes
and vectorization.
Much has been written about photogrammetric techniques and
LIDAR [see Schenk (2001) and Habib et al (2004)] and about
their integration [see P. Ronnholm et al (2007)]. The following
table is a concise comparative table of both techniques
(Photogrammetry mapping: EM 1110-1-1000, 2002):
LIDAR
Photogrammetry
Energy source
Active
Passive
Geometry
Polar
Perspective
Sensor type
Punctual
Matrix or linear
Measurement of
Direct without
Indirect with
points
redundancy.
Accuracy of
information only
depends on
calibration of
system
components
redundancy.
Images with
overlay provide the
intersection of the
homologous rays
(HR)
Information type
Punctual.
Reconstructed
surface (type of
material and
observed structure)
difficult to assess
May be punctual,
lineal or
superficial. Easy to
interpret
reconstructed
model due to info
source: the image
Sampling
Individual points
Full areas
Associated image
None or
monochromatic
image
High geometric
and radiometric
quality
Horizontal
2-5 x less than
1-3 x better than
accuracy
vertical accuracy
vertical accuracy
Vertical accuracy
10-15 cm (~ 10 cm
per 1,000 m on
heights of
2,500 m)
Depends on flight
altitude and focal
length of the
camera
Flight plan
More complete.
Small passes,
Needs
consideration of