• Title/Summary/Keyword: Sub-aperture stitching algorithm

Search Result 3, Processing Time 0.018 seconds

Modified Sub-aperture Stitching Algorithm using Image Sharpening and Particle Swarm Optimization

  • Chen, Yiwei;Miao, Erlong;Sui, Yongxin;Yang, Huaijiang
    • Journal of the Optical Society of Korea
    • /
    • v.18 no.4
    • /
    • pp.341-344
    • /
    • 2014
  • This study proposes a modified sub-aperture stitching algorithm, which uses an image sharpening algorithm and particle swarm optimization to improve the stitching accuracy. In sub-aperture stitching interferometers with high positional accuracy, the high-frequency components of measurements are more important than the low-frequency components when compensating for position errors using a sub-aperture stitching algorithm. Thus we use image sharpening algorithms to strengthen the high-frequency components of measurements. When using image sharpening algorithms, sub-aperture stitching algorithms based on the least-squares method easily become trapped at locally optimal solutions. However, particle swarm optimization is less likely to become trapped at a locally optimal solution, thus we utilized this method to develop a more robust algorithm. The results of simulations showed that our algorithm compensated for position errors more effectively than the existing algorithm. An experimental comparison with full aperture-testing results demonstrated the validity of the new algorithm.

Fast Sub-aperture Stitching Algorithm Using Partial Derivatives

  • Chen, Yiwei;Miao, Erlong;Sui, Yongxin;Yang, Huaijiang
    • Journal of the Optical Society of Korea
    • /
    • v.19 no.1
    • /
    • pp.84-87
    • /
    • 2015
  • For large optical elements which are tested by many sub-apertures, it takes too much time for a sub-aperture stitching algorithm to get the stitching result. To solve this problem, we propose a fast sub-aperture stitching algorithm to quickly compensate for piston, tilt, and defocus errors. Moreover, the new algorithm is easy to understand and program. We use partial derivatives of measurement data to separately solve piston, tilt, and defocus errors. First, we show that the new algorithm has a lower time complexity than the currently used algorithm. Although simulation results indicate that the accuracy of the new algorithm is lower than the current algorithm in all 20 simulations, our experimental results validate the algorithm and show it is sufficiently accurate for general use.

Chirp Stitching Technique for Wideband Signals of the Spaceborne High Resolution Synthetic Aperture Radar (위성탑재 고해상도 합성개구레이더용 광대역 신호 획득을 위한 ? 스티칭 기술 연구)

  • 권오주
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.25 no.10B
    • /
    • pp.1777-1784
    • /
    • 2000
  • In this paper we suggested the chirp stitching algorithm and transmitter/receiver channel to a spaceborne high resolution SAR which enables wideband signal generation and processing with minimum hardware requirement. The transmitter channel generates two sub-band signals and then generate a wideband signal using chirp stitching algorithm and the receiver channel divides a wideband signal into two sub-band signals in order to overcome the high speed data handling capability of this spaceborne systems. We generated and processed a 100 MHz wideband signal evaluated the performance and verified the feasibility of the application of this chirp stitching algorithm and transmitter/receiver channel to spaceborne high resoultion SAR.

  • PDF