scholarly journals Deformation Estimation Using Beidou GEO-Satellite-Based Reflectometry

2021 ◽  
Vol 13 (16) ◽  
pp. 3285
Author(s):  
Yongqian Chen ◽  
Songhua Yan ◽  
Jianya Gong
Keyword(s):  
Low Cost ◽  
Phase Error ◽  
Radar System ◽  
Deformation Monitoring ◽  
Retrieval Algorithm ◽  
Stable Phase ◽  
Integer Number ◽  
Path Delay ◽  
Geometrical Properties ◽  
Geo Satellites

Deformation monitoring has been brought to the fore and extensively studied in recent years. Global Navigation Satellite System Reflectometry (GNSS-R) techniques have so far been developed in deformation estimation applications, which however, are subject to the influence of mobile satellites. Rather than compensating for the path delay variations caused by mobile satellites, adopting Beidou geostationary Earth orbit (GEO) satellites as transmitters directly eliminates the satellite-motion-induced phase error and thus provides access to stable phase information. This paper presents a novel deformation monitoring concept based on GNSS-R utilizing Beidou GEO satellites. The geometrical properties of the GEO-based bistatic GNSS radar system are explored to build a theoretical connection between deformation quantity and the echo carrier phases. A deformation retrieval algorithm is proposed based on the supporting software receiver, thus allowing echo carrier phases to be extracted and utilized in deformation retrieval. Two field validation experiments are conducted by constructing passive bistatic radars with reflecting plates and ground receiver. Utilizing the proposed algorithm, the experimental results suggested that the GEO-based GNSS reflectometry can achieve deformation estimations with an accuracy of around 1 cm when the extracted phases does not exceed one complete cycle, while better than 3 cm when considering the correct integer number of phase cycles. Consequently, based on the passive bistatic radar system, the potential of achieving continuous, low-cost deformation monitoring makes this novel technique noteworthy.

scholarly journals Design and Implementation of a Farrow-Interpolator-Based Digital Front-End in LTE Receivers for Carrier Aggregation

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 231
Author(s):  
Chester Sungchung Park ◽  
Sunwoo Kim ◽  
Jooho Wang ◽  
Sungkyung Park
Keyword(s):  
Integrated Circuit ◽  
Building Block ◽  
Orthogonal Frequency Division Multiplexing ◽  
Critical Path ◽  
Phase Error ◽  
System Level ◽  
Comb Filter ◽  
Carrier Aggregation ◽  
Path Delay ◽  
Front End

A digital front-end decimation chain based on both Farrow interpolator for fractional sample-rate conversion and a digital mixer is proposed in order to comply with the long-term evolution standards in radio receivers with ten frequency modes. Design requirement specifications with adjacent channel selectivity, inband blockers, and narrowband blockers are all satisfied so that the proposed digital front-end is 3GPP-compliant. Furthermore, the proposed digital front-end addresses carrier aggregation in the standards via appropriate frequency translations. The digital front-end has a cascaded integrator comb filter prior to Farrow interpolator and also has a per-carrier carrier aggregation filter and channel selection filter following the digital mixer. A Farrow interpolator with an integrate-and-dump circuitry controlled by a condition signal is proposed and also a digital mixer with periodic reset to prevent phase error accumulation is proposed. From the standpoint of design methodology, three models are all developed for the overall digital front-end, namely, functional models, cycle-accurate models, and bit-accurate models. Performance is verified by means of the cycle-accurate model and subsequently, by means of a special C++ class, the bitwidths are minimized in a methodic manner for area minimization. For system-level performance verification, the orthogonal frequency division multiplexing receiver is also modeled. The critical path delay of each building block is analyzed and the spectral-domain view is obtained for each building block of the digital front-end circuitry. The proposed digital front-end circuitry is simulated, designed, and both synthesized in a 180 nm CMOS application-specific integrated circuit technology and implemented in the Xilinx XC6VLX550T field-programmable gate array (Xilinx, San Jose, CA, USA).

scholarly journals Low-cost GPS-based volcano deformation monitoring at Mt. Papandayan, Indonesia

2002 ◽  
Vol 115 (1-2) ◽  
pp. 139-151 ◽  
Author(s):  
Volker Janssen ◽  
Craig Roberts ◽  
Chris Rizos ◽  
Hasanuddin Z Abidin
Keyword(s):  
Low Cost ◽  
Deformation Monitoring ◽  
Volcano Deformation

scholarly journals A Low-Cost Optical Remote Sensing Application for Glacier Deformation Monitoring in an Alpine Environment

Sensors ◽  
2016 ◽  
Vol 16 (10) ◽  
pp. 1750 ◽  
Author(s):  
Daniele Giordan ◽  
Paolo Allasia ◽  
Niccolò Dematteis ◽  
Federico Dell’Anese ◽  
Marco Vagliasindi ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Low Cost ◽  
Deformation Monitoring ◽  
Optical Remote Sensing ◽  
Alpine Environment ◽  
Remote Sensing Application ◽  
Sensing Application

(Micro)Metering with Microwaves: A Low-Cost, Low-Power, High-Precision Radar System

2019 ◽  
Vol 20 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Fabian Michler ◽  
Benedict Scheiner ◽  
Fabian Lurz ◽  
Robert Weigel ◽  
Alexander Koelpin
Keyword(s):  
Low Power ◽  
High Precision ◽  
Low Cost ◽  
Radar System

Efficient Lightweight Hardware Structures of Point Multiplication on Binary Edwards Curves for Elliptic Curve Cryptosystems

2019 ◽  
Vol 28 (09) ◽  
pp. 1950149
Author(s):  
Bahram Rashidi ◽  
Mohammad Abedini
Keyword(s):  
High Speed ◽  
Critical Path ◽  
Low Cost ◽  
Path Delay ◽  
Point Multiplication ◽  
Low Area ◽  
Elliptic Curve Cryptosystems ◽  
Edwards Curves ◽  
Special Cases ◽  
Field Multiplication

This paper presents efficient lightweight hardware implementations of the complete point multiplication on binary Edwards curves (BECs). The implementations are based on general and special cases of binary Edwards curves. The complete differential addition formulas have the cost of [Formula: see text] and [Formula: see text] for general and special cases of BECs, respectively, where [Formula: see text] and [Formula: see text] denote the costs of a field multiplication, a field squaring and a field multiplication by a constant, respectively. In the general case of BECs, the structure is implemented based on 3 concurrent multipliers. Also in the special case of BECs, two structures by employing 3 and 2 field multipliers are proposed for achieving the highest degree of parallelization and utilization of resources, respectively. The field multipliers are implemented based on the proposed efficient digit–digit polynomial basis multiplier. Two input operands of the multiplier proceed in digit level. This property leads to reduce hardware consumption and critical path delay. Also, in the structure, based on the change of input digit size from low digit size to high digit size the number of clock cycles and input words are different. Therefore, the multiplier can be flexible for different cryptographic considerations such as low-area and high-speed implementations. The point multiplication computation requires field inversion, therefore, we use a low-cost Extended Euclidean Algorithm (EEA) based inversion for implementation of this field operation. Implementation results of the proposed architectures based on Virtex-5 XC5VLX110 FPGA for two fields [Formula: see text] and [Formula: see text] are achieved. The results show improvements in terms of area and efficiency for the proposed structures compared to previous works.

scholarly journals Optimization of the UWB Feed Antenna Position in Reflector Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Nurhan Türker Tokan
Keyword(s):  
High Performance ◽  
Phase Error ◽  
Design Procedure ◽  
Reflector Antenna ◽  
Slot Antenna ◽  
Stable Phase ◽  
Phase Center ◽  
Center Position ◽  
Reflector System ◽  
Novel Method

In reflector system design, achieving high stability of phase center position with changes in frequency in reflector feed antennas is highly desired. However, obtaining highly stable phase center is not possible for UWB feed antennas, specially for planar ones. Thus, an optimum positioning for the UWB feed antenna should be defined. Optimization of the positioning of the feed antenna is essential since this process lowers resulting phase error losses significantly. In this work, a novel method for optimizing the UWB feed position of a prime focus reflector antenna from phase and amplitude recordings of the measured radiated field is introduced. An automatic and fast design procedure, based on Genetic Algorithms, is described. The proposed methodology has been numerically and experimentally assessed. The procedure is introduced by an application example to one of the most commonly used UWB feed antennas in high-performance reflector antenna systems: Linear Tapered Slot Antenna (LTSA). A LTSA antenna operating in 6–25 GHz frequency band is designed and manufactured. The performance of the method is quantified in terms of its phase error losses inE- andH-planes for reflector illumination.

scholarly journals A Cloud Top-Height Retrieval Algorithm Using Simultaneous Observations from the Himawari-8 and FY-2E Satellites

2020 ◽  
Vol 12 (12) ◽  
pp. 1953 ◽  
Author(s):  
Jonghyuk Lee ◽  
Dong-Bin Shin ◽  
Chu-Yong Chung ◽  
JaeGwan Kim
Keyword(s):  
Quality Control ◽  
Image Matching ◽  
Geometric Configuration ◽  
Retrieval Algorithm ◽  
Orthogonal Polarization ◽  
Apparent Position ◽  
Retrieval Accuracy ◽  
Geo Satellites ◽  
The Difference ◽  
Theoretical Accuracy

In this paper, we introduce a cloud top-height (CTH) retrieval algorithm using simultaneous observations from the Himawari-8 and FengYun (FY)-2E geostationary (GEO) satellites (hereafter, dual-GEO CTH algorithm). The dual-GEO CTH algorithm estimates CTH based on the parallax, which is the difference in the apparent position of clouds observed from two GEO satellites simultaneously. The dual-GEO CTH algorithm consists of four major procedures: (1) image remapping, (2) image matching, (3) CTH calculation, and (4) quality control. The retrieved CTHs were compared with other satellite CTHs from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and the Cloud-Profiling Radar (CPR), on three occasions. Considering the geometric configuration and footprint sizes of the two GEO satellites, the theoretical accuracy of the dual-GEO CTH algorithm is estimated as ±0.93 km. The comparisons show that the retrieval accuracy generally tends to fall within the theoretical accuracy range. As the dual-GEO CTH algorithm is based on parallax, it could be easily applied for the estimation of the height of any elevated feature in various fields.

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