il within
tant for
t1,2006).
ampling
IFOV 1s
angualr
ponding
ent the
ree kind
ree kind
k and
UNI.
iddition,
give the
lyse 29
er and
mplified
lution’s
Hua of
fforts in
ont goes
sity and
vey on
August
).
ground-
National
al laser
rencing
/, Royal
‘un and
inners's
)matics,
sing of
'eodesy,
nt cloud
3) , pp.
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
ADVANCES OF FLASH LIDAR DEVELOPMENT ONBOARD UAV
Guoging Zhou, Jiazhi Yang, Xin Li and Xiaoping Yang
Guangxi Key Laboratory for Spatial Information and Geomatics, Guilin University of Technology, Guilin, 541004,
China - glitezhou@yahoo.com
Commission VI, WG VI/2 - Automatic Geospatial Data Acquisition and Image-Based Databases
KEY WORDS: UAV, LiDAR, flash, data acquisition, 3D imagery
ABSTRACT:
À small cost-low civilian UAV (Unmanned Aerial Vehicle - UAV) platform usually requests that all carried components should be
light in weight, small in volume, and efficient in energy. This paper presents the advance of a pre-mature of flash LIDAR system
including laser emitting system, associate with the pulsed voltage technology. A complete laser emitting system, including laser
diode, conic lens, alignment, divergence angle, etc., has been designed and implemented. The laser emitting system is first simulated
and tested using 3D-Tool software, and then manufactured by an industrial company. In addition, a novel power supply topology
based on two coupled coils, pulse generator circuit, and a fast switch, is proposed since several 100 V in voltage, 10-100 A in
current, several hundred millisecond in pulse width is needed for flash LiDAR system onboard a small low-cost civilian UAV
platform, and the traditional power supply had problems in efficiency and bulk. Finally, laser emitting and the power supply are
assembled and tested. The size of laser footprint is 4398.031 mm x 4398.031 mm in x and y axes, respectively, when shitting from a
flight height of 300 m, which is close to the theoretic size of 4.5 m x 4.5 m. The difference of 102 mm can meet the requirement of
flash LiDAR data collection at a flight height of 300 m. Future work on extensive and on-going investigation and investments for a
prototype of flash LiDAR system is drawn up as well.
1. INTRODUCTION
The 3D imagery has widely been applied in such as
terrain mapping, disaster rescue, helicopter obstacle
avoidance, range navigation, urban planning,
environmental monitoring, resource exploration, and so
on. Many technologies have been developed for
automatic acquisition of 3D imagery, such as typical
stereo aerial imager onboard airborne. Compared with
conventional intensity image captured by optical sensors
onboard either airborne or spaceborne, three dimensional
(3D) image captured by active sensor offers more
information about the target, such as elevation, distance,
position and structure (Zhou et al., 2011). Traditionally
typical airborne scanning LiDAR (Light detection and
Ranging) sensor onboard manned airplane is an active
sensor, and is capably of acquiring 3D imagery of an
arbitrary object or scene by measuring the time delay of a
round trip of a laser pulse directed at points.
In recent years, a UAV platform becomes more and more
interesting, since it is capable of quickly reaching the
target area and deploying mission to the remote sites at a
low-cost. A small low-cost civilian UAV platform often
has limitation to its carried components in volume and
weight. These limitations have seriously hindered its
applicability in practice, since it requires lightness in
weight, small in volume, and efficiency in power supply.
For this reason, this paper presents an innovative idea
about airborne flash LiDAR system. The flash LiDAR
Systems are analogous to a camera with a flashbulb
(flood illumination), but with the flash being provided by
laser illumination and the use of a detector with a clock
to determine the time it takes for the flash to depart,
reflect off of the target, and return (***). By measuring
the time of flight of the reflected laser pulse, the sensor
can determine a range measurement along with intensity
for each pixel in the image. This information set over the
range of all detector pixels is referred to as a 3D LiDAR
imagery (Zhou et al., 2011; Yang and Zhou, 2011).
2. DESIGNED FLASH LIDAR FLOWCHART
2.1 General Framework
The proposed flash LiDAR onboard a UAV system is
depicted in Figure 1. As seen from Figure 1, it consists of
five basic functionality modules. They are (1) laser and
laser emitting sub-system, (2) APD and laser receiver
sub-system, (3) micro-control and processing sub-system,
(4) POS subsystem, and (5) LiDAR point cloud post-
processing sub-system. The details of each sub-system
are presented by Zhou and Yan (2011). A brief review is
presented below.
[ Emitting system]]
GID)
7 ;
| [Receiving system)
| Post-processing
Figure 1. The flowchart of airborne flash LiDAR system
