Istanbul 2004 International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B2. Istanbul 2004
the digitized the largest non-terrain object. Finally, the coarse DTM is integrating information about terrain relief, slope and data
tation height refined hierarchically from the top level to the bottom level. At density. The non-terrain points are replaced by interpolated
e remaining each level, denser terrain points are identified, and a smooth elevations using surrounding terrain points. The bottom-level
condition is employed to improve the processing efficiency by image represents the expected bare Earth surface.
MA Airfield [ Digital Elevation Data: Lidar | | Digital Photo Data: Aerallmage | GIS Data: Topographical IM.
that protrude S - | | ry paw eT |
| Specification: Airfield Init. Doc. |
Vehicular
OIS Y
Y
( Scanning |
| T
e regard as Filtering Filtered Qutliers
ions, one of Ÿ
g, 2002), is F- Lidar DSM 1 Comparson& |
cation levels, Digitization
vel must be
Digital Image Processing
Traverse = G ic Resistration &
à ; r Surfaces Geometnc Registration &
the National seen Ways | Correction using GCPs
buildings, or DEM/DTM 1 Y = :
ns and need ( Manual Digitization m S Bilinear Interpolation
his level are ( Elevation Subtraction ] [ RC] Comparison & ECL 3
t uildinsss Sr Vist] Airfield Backgroun
OIS-related EET Buildings shp i Digitization | Airfield Background — |
runway and ideni :
toi vi ects Y. | | Residential Areas shp | | Y Spatial Selection &
C s 8018, Calculation asie iL. 7 d Data Conversion
f factors are : [ Bissein Moret | BARS:
ifvi Trees/Bush oads shp Ÿ
ifying and Datasets Grids Vector/Raster Conversion Rivers shp
I
v Y Four Raster Layets
[- Subtraction f Raster Calculation ] 3 Distance
| Runway Center Lines | icai
Em
rate Buffered C. i Sm
Hiusteaies [ RasterfVector Conversion ] ( bie Corer Lines J Penetration
lidar data ^w = Ÿ
plies image , a Saaty Risk Modeling:
le the DTM '' - aty Risk Modeling:
e ( Datasets Ivlerger ] |. 3D Visualization of 2 Gustuction Raster Reclassification
ildings and
he forested Obstructions shy Add Attributes
lential areas
IS surfaces,
Map Calculation
| Airfield Obstruc tions “Identification | ^ ;
"nn í,, "m T Sequencing & Rendering
SVTW. The Figure 2. Project workflow
nd bilinear
new map is In Figure 3, TIN is used to visualize the continuous surfaces of ;
erge all the the DSM (3a) and DTM (3b) (Burrough and McDonnell, 1998). DSM-Diagonal
be recorded
'rs make a P 150
s are added. d
the finally s — 100
ulation and |, m
| qd
| = #5
| ü
:ct products Ü 5000 10000 —— 15000
oint clouds Ricco a
covered by NI or lip oA Profile Graph
ig, the raw
or blunders,
' very large
A median DEM-Diagonal
r removing | E pT QE 150
e by which | joe hal
the central u
£. 100
Figure 3b. 3D Visualization of the DTM gom
ical terrain , = 50
algorithm Figure 4 shows the two profiles along with the pink diagonal
and other lines in Figures 3a and 3b, respectively. It can be observed that ff
ot
rface in a the DSM surfaces are more complex than the DTM's. This is d CODD 10000 Tan
unders, the because the DSM includes all non-terrain objects, but the DTM
ased range shows the bare terrain surface only. Profile Graph
| each grid. :
el image is When the DTM is generated, we also obtain an estimate to the dea
larger than DNM by subtracting the DTM from the raw lidar range image. Figure 4. Profiles in the DSM (top) and the DTM (bottom)