scholarly journals Analysis of a Bistatic Ground-Based Synthetic Aperture Radar System and Indoor Experiments

2020 ◽  
Vol 13 (1) ◽  
pp. 63
Author(s):  
Hoonyol Lee ◽  
Jihyun Moon
Keyword(s):  
Synthetic Aperture Radar ◽  
Early Stage ◽  
System Development ◽  
Cost Effective ◽  
Projection Algorithm ◽  
Synthetic Aperture ◽  
Receiving Antenna ◽  
Transmitting Antenna ◽  
System Configurations ◽  
Aperture Radar

Recent advancement of satellite synthetic aperture radar (SAR) techniques require more sophisticated system configurations such as the use of bistatic antennas or multi-frequencies. A ground-based experiment is a cost-effective and efficient way to evaluate those new configurations especially in the early stage of the system development. In this paper, a ground-based synthetic aperture radar (GB-SAR) system was constructed and operated in a bistatic mode at Ku-band where a receiving antenna (Rx) follows a transmitting antenna (Tx) separated by a baseline B. A new bistatic GB-SAR focusing algorithm was developed by modifying a conventional range-Doppler algorithm (RDA), and its performance has been evaluated by comparing the results with those from a back-projection algorithm (BPA). The results showed good performance of RDA at far range approaching nominal resolutions of 9.4 cm in range and 4.5 cm in azimuth, but limited quality at near range due to the approximation used in RDA. Signals from three trihedral corner reflectors (CR) reduced with increasing B, showing a typical bidirectional scattering behavior of CR. This GB-SAR system will be a testbed for new SAR imaging configurations with variations in antenna positions and target properties.

scholarly journals Passive Bistatic Ground-Based Synthetic Aperture Radar: Concept, System, and Experiment Results

2019 ◽  
Vol 11 (15) ◽  
pp. 1753 ◽  
Author(s):  
Weike Feng ◽  
Jean-Michel Friedt ◽  
Giovanni Nico ◽  
Suyun Wang ◽  
Gilles Martin ◽  
...  
Keyword(s):  
Synthetic Aperture Radar ◽  
Field Experiments ◽  
Continuous Wave ◽  
Phase Synchronization ◽  
Local Area ◽  
Low Noise ◽  
Projection Algorithm ◽  
Synthetic Aperture ◽  
Concept System ◽  
Aperture Radar

A passive bistatic ground-based synthetic aperture radar (PB-GB-SAR) system without a dedicated transmitter has been developed by using commercial-off-the-shelf (COTS) hardware for local-area high-resolution imaging and displacement measurement purposes. Different from the frequency-modulated or frequency-stepped continuous wave signal commonly used by GB-SAR, the continuous digital TV signal broadcast by a geostationary satellite has been adopted by PB-GB-SAR. In order to increase the coherence between the reference and surveillance channels, frequency and phase synchronization of multiple low noise blocks (LNBs) has been conducted. Then, the back-projection algorithm (BPA) and the range migration algorithm (RMA) have been modified for PB-GB-SAR to get the focused SAR image. Field experiments have been carried out to validate the designed PB-GB-SAR system and the proposed methods. It has been found that different targets within 100 m (like the fence, light pole, tree, and car) can be imaged by the PB-GB-SAR system. With a metallic plate moved on a positioner, it has been observed that the displacement of the target can be estimated by PB-GB-SAR with submillimeter accuracy.

scholarly journals ESTIMATION OF DATA MEMORY CAPACITY FOR CIRCULARLY POLARIZED SYNTHETIC APERTURE RADAR ONBOARD UNMANNED AERIAL VEHICLE PLATFORM (CP-SAR UAV)

2011 ◽  
Vol 7 (1) ◽  
Author(s):  
P. Rizki Akbar ◽  
J.T. Sri Sumantyo ◽  
V.C.Koo ◽  
H.Kuzel
Keyword(s):  
Synthetic Aperture Radar ◽  
Unmanned Aerial Vehicle ◽  
Early Stage ◽  
Low Cost ◽  
Image Data ◽  
Memory Capacity ◽  
Synthetic Aperture ◽  
Circularly Polarized ◽  
Aerial Vehicle ◽  
Aperture Radar

Previously only linear polarization is widely used in the Synthetic Aperture Radar(SAR) system onboard spaceborne and airborne platforms. In such linearly polarized SAR(LP-SAR) systems, Faraday rotation in the ionosphere and platform posture will contribute tothe system noise. Therefore to improve this situation, currently a novel Circularly PolarizedSynthetic Aperture Radar (CP-SAR) sensor is developed in Microwave Remote SensingLaboratory, Chiba University. Moreover, from this research, a new backscattering data basedon circularly polarized wave in the remote sensing field can be obtained. As an early stage ofthe development of this CP-SAR sensor, we built an Unmanned Aerial Vehicle (UAV)platform for testing CP-SAR sensor capabilities. In this paper, we describe the novel CP-SARsensor and the method to design CP-SAR UAV especially in estimating the requirement ofdata memory capacity. Also a smaller antenna is possible to be implemented since the 3-dBaxial ratio on antenna characteristic becomes the main parameter in this new CP-SARtechnique. Hence, a compact CP-SAR sensor onboard a small and low cost spaceborneplatform yielding a high accuracy SAR image data can be realized in the near future.

scholarly journals Sensitivity Analysis of Multi-Temporal Sentinel-1 SAR Parameters to Crop Height and Canopy Coverage

2019 ◽  
Vol 9 (4) ◽  
pp. 655 ◽  
Author(s):  
Rouhollah Nasirzadehdizaji ◽  
Fusun Balik Sanli ◽  
Saygin Abdikan ◽  
Ziyadin Cakir ◽  
Aliihsan Sekertekin ◽  
...  
Keyword(s):  
Synthetic Aperture Radar ◽  
Early Stage ◽  
Strong Relationship ◽  
Synthetic Aperture ◽  
Crop Height ◽  
Canopy Coverage ◽  
Broad Leaf ◽  
Multi Temporal ◽  
Low Sensitivity ◽  
Aperture Radar

The Polarimetric Synthetic Aperture Radar technique has provided various opportunities and challenges in agricultural activities mainly on crop management. The aim of this study is to investigate the sensitivity of 10 parameters derived from multi-temporal Sentinel-1 Synthetic Aperture Radar (SAR) data, to crop height and canopy coverage (CC) of maize, sunflower, and wheat. The correlation coefficient values indicate a high correlation for maize during the early growing stage. The coefficient determinations (R2) of 0.82 and 0.81 indicate that there is a strong relationship between the maize height and SAR parameters including VV + VH and VV, respectively. The maize CC is well correlated with VV parameter (R2 = 0.73), but it is observed that at the later growing stage the correlation became weaker. This means that the sensitivity decreases with increasing vegetation cover growth. Compared to maize, the sensitivity of SAR parameters to wheat variables is often good at the early stage. However, the highest correlation with wheat height represented by Alpha (α) decomposition parameter (R2 = 0.67). The sunflower height has an insignificant correlation with the majority of SAR parameters and only VH polarization shows low sensitivity (R2 = 0.31). The sunflower CC shows relatively higher correlation with VV polarization (R2 = 0.46) at the early stage while no considerable correlation is observed at the later stage. It is found that Sentinel-1 has a high potential for estimation of crop height and CC of the maize as a broad-leaf crop. The same is not true for sunflower as another broad-leaf crop.

Data Visualization for Low-Frequency Inverse Synthetic Aperture Radar (ISAR)

2018 ◽  
Vol 10 (3) ◽  
pp. 1-8
Author(s):  
Giti Javidi ◽  
Ehsan Sheybani
Keyword(s):  
Time Delay ◽  
Synthetic Aperture Radar ◽  
Real Time ◽  
Data Visualization ◽  
Systematic Approach ◽  
Low Frequency ◽  
Synthetic Aperture ◽  
Receiving Antenna ◽  
Transmitting Antenna ◽  
The Relationship

The purpose of this article was to use ISAR to determine the distance between the receiving antenna and the transmitting antenna. Once a systematic approach has been determined, this article could be used on a spacecraft to locate debris in the path of the carrier. Using low frequency radar that has the transmitting pulse built within the converters, the authors transmitted the data and determined the distance between the two antennas according to the time delay of the radar. Using amplified signals, the relationship between the distance and the time delay for the radar were calculated for each case. Additionally, these results were used to visualize in real-time the data transpired between the receiver and transmitter.

scholarly journals An FPGA based Real-Time Multi-Target Synthetic Aperture Radar Echoes Synthesizer

2020 ◽  
Vol 2 (2) ◽  
pp. 10-16
Author(s):  
Chua Ming Yam ◽  
Koo Voon Chet ◽  
Lim Heng Siong ◽  
Chan Yee Kit
Keyword(s):  
Synthetic Aperture Radar ◽  
Real Time ◽  
System Development ◽  
Synthetic Aperture ◽  
Multiple Point ◽  
Direct Digital Synthesis ◽  
Radar Echoes ◽  
Field Programmable ◽  
Complex Mathematical Model ◽  
Aperture Radar

This paper proposes a technique for synthesizing multiple point target scatterer Synthetic Aperture Radar (SAR) echoesin real-time. Traditional approaches require high computation resources to calculate the complex SAR echoes due to its complex mathematical model. The proposed technique employs the low computation Direct Digital Synthesis (DDS) approach to generate these complex sinusoid echoes. The proposed Synthetic Aperture Radar Echoes Synthesizer(SAR-ES)is capable of synthesizing SAR echoes accurately in real-time and was built in a Field Programmable Gate Array (FPGA) platform. The system can be used as a testbed to validate and evaluate the performance of a real-time SAR processing algorithms/system prior to the actual flight mission. This could help in reducing the frequency of flight trials and to reduce the SAR system development risk especially for satellite-borne SAR system.

A Novel Fast Factorized Back-projection Algorithm for Synthetic Aperture Radar Imaging

2014 ◽  
Vol 35 (6) ◽  
pp. 1435-1441 ◽  
Author(s):  
Hao-lin Li ◽  
Lei Zhang ◽  
Lei Yang ◽  
Ya-chao Li ◽  
Meng-dao Xing ◽  
...  
Keyword(s):  
Synthetic Aperture Radar ◽  
Radar Imaging ◽  
Projection Algorithm ◽  
Synthetic Aperture ◽  
Back Projection ◽  
Aperture Radar
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