Nonlinear Range Cell Migration (RCM)
Compensation Method for Spaceborne/Airborne Forward-Looking Bistatic SAR
Zhe Liu , Jianyu Yang, Xiaoling Zhang School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
Presentation by Zhe Liu
1
Outline

Introduction to the SA-FBSAR and its nonlinear RMC

Nonlinear RCM compensation method

Simulation results

Conclusions and further work
Range cell migration (RCM) features are : Vary with the target’s range and azimuth location

· Dramatic geometric difference
· Essential velocity difference

Imaging scene
3
Introduction－Emergence of SA-FBSAR
Monostatic SAR
Bistatic/ Multistatic SAR(B/M SAR)
• Diversity of target information • High immunity to attacks • Low cost • Wide coverage, high SNR • Platform flexibility • Power saving • wide band • repeated observation • attractive potential for aircraft landing and 4 navigation

transmitter
Working Modes: Transmitter antenna works in side-looking or squint-looking mode; receiver antenna in forwardlooking mode.

receiver
Target imaging scene: Target scene is along the receiver’s forward-looking direction
Spaceborne B/M SAR
S-A B/M Airborne SAR B/M SAR
Commu. satellite
SA-BSAR with radar Broadcast satellite Radar
satellite
satellite
SA-FBSAR
Introduction－Emergence of SA-FBSAR
8
Introduction－effect of nonlinear RCM on imaging results
y x
(a) original area target
(b) Without RCMC
Fig3. Imaging result of area targets
9
Introduction－Our work
Introduction－effect of nonlinear RCM on imaging results
(a) original point scatterers
(b) without RCM compensation
Fig2. Imaging result of point targets
Fig.1 Imaging result of the first SA-FBSAR feasibility experiment in 2009
In Nov. 2009, FGAN (German Aerospace Center) launched the first experiment to test the feasibility of SA-FBSAR.
Satellite velocity：7.4 7.6km/s
Aircraft velocity：100m/s
· Different working mode
Satellite : side-looking Aircraft : forward-looking
6
Hale Waihona Puke Introduction－Challenges of SA-FBSAR imaging
· Different working mode
exhibits significant nonlinearity with target’s range location

Severe distortion and nonlinear misregistration will occur, if such 7 RCM is not properly compensated
5
Introduction－Challenges of SA-FBSAR imaging
· Dramatic geometric difference
Satellite height：500800km Aircraft height：1 - 5km
· Essential velocity difference
2
Introduction－What is SA-FBSAR
Spaceborne/Airborne ForwardLooking Bistatic SAR (SA-FBSAR) Platforms: Transmitter and receiver of SA-FBSAR are low earth orbit (LEO) satellite and aircraft, respectively.