Autofocus Correction of Residual RCM for VHR SAR Sensors With Light-Small Aircraft

Li, Ning; Wang, Robert; Deng, Yunkai; Yu, Weidong; Zhang, Zhimin; Liu, Yabo

doi:10.1109/tgrs.2016.2608423

Cited by 37 publications

(20 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, the proposed method can be deemed to perform satisfactorily on point target simulation. In order to validate the effectiveness of the proposed method on area target simulation further, image contrast (IC) [25] and image entropy (IE) [26] are chosen to evaluate the quality of focused results [27]. In [25], it is proposed that better focusing leads to larger IC.…”

Section: Discussionmentioning

confidence: 99%

High Resolution Imaging from Azimuth Missing SAR Raw Data via Segmented Recovery

Qian

Zhu

2019

Electronics

View full text Add to dashboard Cite

Synthetic Aperture Radar (SAR) raw data missing occurs when radar is interrupted by various influences. In order to cope with this problem, a new method is proposed to focus the azimuth missing SAR raw data via segmented recovery in this paper. A reference function in time domain is designed to make the missing raw data sparser in two dimensional frequency domain. Afterwards, greedy algorithms are available to recover the missing data in two dimensional frequency domain. In addition, in order to avoid range frequency aliasing problem caused by reference function multiplication in time domain, the missing raw data is split into several parts in range direction and is recovered with a segmented recovery strategy. Then, the recovered raw data is available to be focused with traditional SAR imaging algorithms. The range migration algorithm is chosen to deal with the recovered raw data in this paper. Point target and area target simulations are carried out to validate the effectiveness of the proposed method on azimuth missing SAR raw data. Moreover, the proposed method is implemented on real SAR data in order to further provide convincing demonstration.

show abstract

Section: Discussionmentioning

confidence: 99%

High Resolution Imaging from Azimuth Missing SAR Raw Data via Segmented Recovery

Qian

Zhu

2019

Electronics

View full text Add to dashboard Cite

show abstract

“…As an alternative approach, the phase error can be calculated directly from the raw data using autofocus algorithms. In our research, the phase gradient algorithm (PGA) was used to iteratively calculate the phase error for each pulse, which is used to correct the data [49]- [52]. For a rigidly connected antenna, phase error due to non-ideal motion is common to each channel, thus phase error calculated using Ch1 data was used to compensate the motion error for both channels [53].…”

Section: B Signal Processingmentioning

confidence: 99%

Multichannel W-Band SAR System on a Multirotor UAV Platform With Real-Time Data Transmission Capabilities

et al. 2020

View full text Add to dashboard Cite

In recent years, the demand for small-scale remote sensing, which is used in disaster monitoring, agriculture, and ground subsidence has increased. A multichannel synthetic aperture radar (SAR) system can provide image and topographic information of the illuminated scene, regardless of adverse weather conditions. As a cost-effective solution to radar imaging, a multichannel W-band SAR system mounted on a multirotor unmanned aerial vehicle (UAV) is presented. The radar module was designed to operate at W-band to achieve small size and weight allowing the module to be mounted on multirotor UAVs with small payload. A detailed description of the design and measurement of the system is provided in this paper. The radar imaging capability of the developed system was verified by performing outdoor experiments using isolated buildings as targets. The multichannel functionality of the system was verified by measuring height of a point target placed above the ground. The measurements and experiments verified the feasibility of a multichannel radar mounted on a multirotor UAV for imaging and topographic applications.

show abstract

“…Synthetic aperture radar (SAR) has become an indispensable means for remote sensing, which is competent to provide high resolution images and videos for monitoring various targets under any weather condition [1][2][3][4][5][6][7]. With the desire for higher resolution, the future task of spaceborne SAR challenges the development of SAR imaging algorithms [8].…”

Section: Introductionmentioning

confidence: 99%

Focusing of Ultrahigh Resolution Spaceborne Spotlight SAR on Curved Orbit

Qian

Zhu

2019

Electronics

View full text Add to dashboard Cite

Aiming to acquire ultrahigh resolution images, algorithms for spaceborne spotlight synthetic aperture radar (SAR) imaging typically confront challenges of curved orbit and azimuth spectral aliasing. In order to conquer these difficulties, a method is proposed in this paper to obtain ultrahigh resolution spaceborne SAR images on a curved orbit, which is composed of the modified RMA (Range Migration Algorithm) and the modified deramping-based approach. The modified RMA is developed to deal with the effect introduced by a curved orbit and the modified deramping-based approach is utilized to handle the problem of azimuth spectral aliasing. In the modified RMA, the polynomial expression of SAR two-dimensional spectrum on a curved orbit is derived with fourth-order azimuth phase history model and series reversion. Then, the singular value decomposition (SVD) is applied to decompose the expression of SAR two-dimensional spectrum numerically in order to acquire coordinates for Stolt interpolation in the scenario of curved orbit. In addition, the modified deramping-based approach is derived by introducing orbital state vectors in order to accommodate the situation of curved orbit in the proposed method. Experiments are implemented on point target simulation in order to verify the effectiveness of the presented method. In experiments, the range and azimuth resolution can achieve 0.15 m and 0.14 m, with focused scene size of 3 km by 3 km.

show abstract

Autofocus Correction of Residual RCM for VHR SAR Sensors With Light-Small Aircraft

Cited by 37 publications

References 42 publications

High Resolution Imaging from Azimuth Missing SAR Raw Data via Segmented Recovery

High Resolution Imaging from Azimuth Missing SAR Raw Data via Segmented Recovery

Multichannel W-Band SAR System on a Multirotor UAV Platform With Real-Time Data Transmission Capabilities

Focusing of Ultrahigh Resolution Spaceborne Spotlight SAR on Curved Orbit

Contact Info

Product

Resources

About