3) For other scanners: The theoretical minimum
dimensionless E/FOV N(<l); The dimensionless angular
quantisation(<0.545);
4) For Riegl LMS-Z390, Riegl VZ-1000, Riegl VZ-400,
Callidus CPW8000, Callidus CP320: N,.. and k, achieve
minimum values, À =5.56, Nn = 0.86 ;
min
5) For Basis Software Surphase : N,, and k, achieve
maximum values, k, 214.43, N,,, 2223;
6) For Faro LS880: k, achieve minimum values, &, 20.2 ;
7) The size of spot diameter affects a lot on minimum angular
resolution, which arises the most in low-precision scanners.
Furthermore, angular resolution of point cloud is as an
integrated result of scanning interval, angular accuracy
and spot diameter. Meanwhile, the method of spot-overlay
can improver angular resolution of point cloud, with a
maximum value of 0.86 times of spot diameter.
Table 1. The coefficient of the formulas of different scanner’ s
beamwidth diameter
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B3, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
Method TLS System D, y R, Wa c
Basis Software Surphaser 25HS 2.8 4.52 2.32 0.3481
BasisSoftware Surphaser 25HSX 2.8 4.32 232 0.3481
Firtst Leica ScanStation 2 6 25 4.00 0.1789
Leica ScanStation C10 6 25 4.00 0.1789
Leica HDS3000 6 25 4.00 0.1789
I-Site 4400-LR 15 1400 5.36 7.50 2.4249
I-Site 4400-CR 15 1400 5.36 7.50 2.4249
I-Site 8800 8 250 17 4.30 0.3968
OptechILRIS-3DER 14 170 50 8.00 0.2298
Third Leica HDS4400 20 1400 7.14 19.00 2.4248
Riegl LPM-321 60 800 50 40.00 0.8944
Riegl LMS-Z420i 8 300 11.67 3.50 0.6166
Riegl LMS-Z620 14 150 18.33 2.80 0.7482
Riegl VZ-400 7 300 6.67 2.00 1.0062
Riegl VZ-1000 7 300 6.67 2.00 1.0062
Callidus CPW 8000 3 200
Z+F Imager 5003 3.3 214
Z+F Imager 5006 3 220
Faro LS 420 3 250
Second Faro LS 840 3 250
Faro LS 880 3 250
Faro Photo 120 33 320
Faro Photo 20 33 320
Optech ILRIS-HD 92 150
Table 2. The value of the scanning interval &, and Æ, as well as
the dimensionless theoretical minimum angular resolution
Class TLS System m k k, Ne EIFOV,...
Trimble GX 0.50 6.41 0.22 0.98 2.93
Trimble GS 1.14 9.17 / 1. 4.20
Fine Leica ScanStation 2 0.50 6.41 0.22 0.98 5.87
Leica HDS3000 0.50 6.41 0.22 0.98 5.87
Leica HDS4500 0.30 5.88 0.46 0.9 5.41
Basis Software Surphaser25HS 2.08 14.5 / 2.23 9.35
Trimble CX 0.27 5.82 0.48 0.89 11.61
Z+F Imager 5006 0.44 6.23 0.33 0.95 13.31
Leica HDS6100 0.45 6.26 0.31 0.96 13.37
Riegl LMS-Z420i 0.14 5.63 0.53 0.87 13.90
Leica HDS6000 0.45 6.26 0.31 0.96 13.37
BasisSoftwareSurphaser25HSX 0.17 5.66 0.52 0.87 13.96
Riegl LMS-Z390 0.03 5.56 0.54 0.86 15.52
Medium Riegl VZ-1000 0.03 $38 0.54 0.86 15.52
Riegl VZ-400 0.03 5.56 0.54 0.86 15.52
Faro LS 880 0.51 6.44 0.20 0.98 15.23
Z+F PROFILER 5006h 0.63 6.87 / 1.05 14.63
Trimble FX 0.39 6.09 0.39 0.93 16.85
Optech ILRIS-HD 0.13 5.62 0.53 0.87 18.65
Z+F Imager 5003 0.63 6.87 / 1.05 14.63
Faro Photo 120 0.41 6.14 0.36 0.94 18.12
OptechILRIS-3DER 0.18 5.67 0.52 0.87 19.67
Riegl LPM-321 0.20 5.70 0.51 0.88 35.10
3rdTech DeltaShpere-3000 0.34 5.97 0.43 0.91 35.72
3rdTech DeltaShpere-3000IR 0.34 5.97 0.43 0.91 35.72
Coarse Callidus CPW 8000 0.02 5.56 0.54 0.86 88.84
I-Site 4400-LR 0.25 5.78 0.49 0.89 62.16
Leica HDS4400 0.50 6.41 0.22 0.98 68.45
Callidus CP 3200 0.02 5.56 0.54 0.86 200.12
5. CONCLUSIONS
Spatial resolution governs the level of identifiable detail within
a scanned point cloud and is particularly important for
recording of objective features with fine details(Lichti,2006).
The angular resolution of laser scanners is affected by sampling
interval, laser beamwidth and angular quantisation. EZFOV is
regarded as a more appropriate measure of the angualr
resolution. To quickly obtain scanning interval corresponding
with the known angular resolution, here we present the
dimensionless AMTF and EIFOV generic model, the three kind
methods of calculating beamwidth diameter, and the three kind
functional relationship that is the relationship of k and
m where N = k , the relationship of k, and m where N=1,
and the relationship of N... and m where k =0. In addition,
we derive the above relationsips’ simplified formula, give the
definition of the optimal sampling interval, and analyse 29
available TLS systems’ laser beamwidth diameter and
variables k, , k, and N,,, . The results shows that the simplified
formulas have direct significance on the angular resolution's
calculation and the scanning interval setting.
ACKNOWLEDGMENT
The authors would like to thank Prof. Xianghong Hua of
Wuhan University for his professional expertis and efforts in
supporting this research work. The other acknowlegment goes
to Associate professor Xing Liu of Chongqing University and
Dr. Junning Liu of Wuhan University for their help.
REFERENCES
Mathias Lemmens, 2010. The fourth Product Survey on
Terrestrial Laser Scanners “Terrestrial Laser Scanners, August
2010”, GIM International.
http://www. gim-international.com/productsurvey/id4 1 -
Terrestrial Laser Scanners, Augusthtml (August. 2010).
Lai Zhikai, 2004. Accuracy analysis and calibration of ground-
based laser scanners. Master thesis in Geodesy, National
Chenggong University, pp.11-21.
Lichti D.D, 2006. Angular resolution of terrestrial laser
scanners. Photogrammetric, 21(14), pp. 141-160.
Reshetyuk Y, 2009. Self-calibration and direct georeferencing
in terrestrial laser scanning. Doctoral thesis in Geodesy, Royal
Institute of Technology, pp. 10-15.
Yang Ronghua, Hua Xianghong, Qiu Weiing, Tang Kun and
Geng Tao, 2011. Research on the terrestrial laser scanners’s
angular resolution of any direction. Journal of Geomatics,
36(3) , pp. 11-12,54.
Zhang Yi, 2008. Research on Point Cloud Processing of
Terrestrial Laser Scanning. Doctoral thesis in Geodesy,
Wuhan University, pp. 1-16, 24-28.
Zhu Ling and Shi Ruoming, 2008. Research on the point cloud
resolutioins of TLS. Journal of Remote Sensing, 12(3) , pp.
405-410.
AB
ligt
inc
dio
and
bas
cur
pla
ass
flig
flas
pro
Th
ter
avi
em
on.
aut
ste
col
oni
(3I
inf
po
tyr
ser
art
roi
In
int
tar
lo
ha:
We
ap
We
Fo
ab
sy
