Some flying objects have high velocity between 10 to 20 Mach, causing extra Doppler dispersion in wideband LFM signal which will deteriorate the ISAR imaging resolution and quality. Also, the detection and imaging of such high-speed objects demands highly on the real-time performance of imaging compensation algorithm. This paper presents a microwave photonic based radar and its compensation algorithm by using digital signal processing. Experiments obtain a clear and high-resolution ISAR image of the high-speed target with velocity of 15Mach. The image has the resolution of 3.12cm*19.12cm, and it just needs 0.30 seconds to do the ISAR imaging.
We propose and demonstrate a reconfigurable photonic fractional Fourier transformer (PFrFTer). A linear chirp light serves as the fractional Fourier transform (FrFT) kernel to rotate the time-frequency plane, forming an optical fractional Fourier domain (FrFD). The input signal is projected on the FrFD, and the FrFT of the signal is obtained. The order of the PFrFTer is reconfigurable and can be adjusted by changing the chirp rate of the light. In the experiment, we obtain the FrFT results of a typical linear frequency modulated wave (LFMW) with a bandwidth of 12 GHz at different orders based on the PFrFTer. By comparing these results with the digital FrFT calculation, it is found that the mean square error between them is less than 4×10-4, which confirms the effectiveness of the PFrFTer. Besides, we demonstrate a practical application of the reconfigurable PFrFTer: the absolute measurement of the chirp rate of an LFMW.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.