GEO-UAV BISTATIC CIRCULAR SYNTHTIC APERTURE RADAR: CONCEPTS AND
TECHNOLOGIES
Qilei Zhang, Zhen Dong, Yongsheng Zhang, Zhihua He
College of Electronic Science and Engineering, National University of
Defense Technology, Changsha, P. R.China,410073
Email: zhangqilei@nudt.edu.cn
ABSTRACT
This paper proposed an innovative bistatic radar system,
named as GEO-UAV bistatic circular synthetic aperture
radar (BCSAR). In GEO-UAV BCSAR, the geostationary
satellite serves as the transmitter, while the receiver is
mounted on the UAV platform moving along a circular
trajectory. Combining the technical advantages of GEO SAR
and that of UAV platform, GEO-UAV BCSAR benefits
from low-cost, high operational flexibility and 3-D imaging
ability. This paper introduced its system concept, and
discussed its imaging ability and technical challenges. It is
shown that the proposed GEO-UAV BCSAR could be able
to provide a potential alternative for future remote sensing
missions.
Index Terms—
geostationary (GEO), unmanned aerial
vehicle (UAV), bistatic SAR(BSAR), bistatic circular SAR
(BCSAR)
1. INTRODUCTION
GEO-UAV bistatic circular synthetic aperture radar
(BCSAR) is an innovative bistatic remote sensing system, in
which the geostationary satellite is used as the transmitter,
while the receiver is mounted on the UAV platform moving
along a circular trajectory. Compared with the conventional
low earth orbit (LEO) SAR, GEO illuminator can be able to
persistently provide vast illuminating coverage with reduced
vulnerability [1-2]. Thus, it is an ideal choice for
transmitters for a BSAR system. Similarly, unmanned aerial
vehicle (UAV) is a suitable platform, since it benefits from
low-cost and reduced vulnerability to counter-measurement
[3]. Furthermore, if UAV moves along a circular trajectory,
more technical advantages, such as 3-D imaging ability,
could be achieved. To sum up, GEO-UAV BCSAR can be
applied to obtain multi-dimensional images with high
temporal and spatial resolutions, high operational flexibility
and quick response. Consequently, it is a promising
technique with great potential.
1
This work was supported by the National Natural Science
Foundation of China (61501477, 61401480).
Scientific activities of establishing bistatic SAR systems
using geosynchronous/geostationary satellites as the
transmitter are a popular. In 1997, G.L. Guttrich et al
proposed a BSAR system using geostationary illuminator
and assuming UAVs as the receiver's platform [4]. Then,
Ref [5] analyzed the resolution performance of such a BSAR
system. In [6], a GEO-BSAR system was proposed with
inclined geosynchronous transmitter and airborne receiver,
and the synchronization approach was analyzed. Recently,
the analysis of imaging performance and system geometry
was presented in [7].
In this paper, the system concepts and technologies of GEO-
UAV BCSAR is studied. Section 2 introduces the system
concept and develops the range history for an arbitrary target.
Then, the imaging features, including spectrum, point spread
function (PSF) and 3-D imaging ability, are analyzed.
Following, section 4 discusses the essential technical
challenges, mainly about synchronization, imaging algorithm
and motion compensation. Finally, some conclusions are
presented.
2. SYSTEM CONCEPT