A Compensator for Large Antennas Based on Pointing Error Estimation Under a Wind Load

Zhang, Jie; Huang, Jin; Zhou, Jun; Wang, Congsi; Zhu, Yun Ming

doi:10.1109/tcst.2016.2631134

Cited by 16 publications

(16 citation statements)

References 13 publications

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“…In this simulation, the adjustment to the best fitting location is discussed. According to (20), (25), and (26), the adjustments of the main reflector and the sub-reflector can be directly obtained. Fig.…”

Section: Methods B: Adjustment To the Best Fitting Locationmentioning

confidence: 99%

“…However, for deformations caused by timevarying temperature and wind, it will be very difficult to realise compensation because the deformations are unknown. Many researchers have studied the compensation methods for the effects of wind and temperature [20,21]. For example, pressure sensors can be adopted in studies related to wind, and a thermal control system with a closed-up backup structure can be used to minimise the effect of temperature.…”

Section: Introductionmentioning

confidence: 99%

“…Δn a(fitting) = sign(Δn a(fitting) ) ⋅ norm ñ′ a z a(fitting) ′s − z a ′s / ñ′ a z(20) wherethe operator norm • represents the length of the bracketed vector, the operator ( • ) z represents a vector's z-component, the operator sign( • ) is the sign function, and ñ′ a is the unit normal vector of the best fitting reflector sign(Δn a(fitting) For the sub-reflector, the coordinates of the points O s ′ and D s ′ in the instrument coordinate system can be expressed as (0, 0, 0) and (0, 0, z O s r − z D s r ), respectively, and can be further rewritten as fourdimensional coordinates such as (0, 0, 0, 1) and (0, 0, z O s r − z D s r , 1).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Surface adjustment strategy for a large radio telescope with adjustable dual reflectors

Lian

Wang

Xue

et al. 2019

IET Microwaves, Antennas & Propagation

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With the development of large-aperture and high-frequency radio telescopes, a surface adjustment procedure for the compensation of surface deformations has become of great importance. In this paper, an innovative surface adjustment strategy is proposed to achieve an automated adjustment for the large radio telescope with adjustable dual reflectors. In the proposed strategy, a high-precision and long-distance measurement instrument is adopted and installed on the back of the sub-reflector to measure the distances and elevation angles of the target points on the main reflector. Here, two surface adjustment purposes are discussed. The first purpose is to ensure that the main reflector and the sub-reflector are always positioned at their ideal locations during operation. The second purpose is to adjust the main reflector to the location of the best fitting reflector, and the sub-reflector to the focus of the best fitting reflector. Next, the calculation procedures for the adjustments of the main reflector and the sub-reflector are discussed in detail, and corresponding simulations are carried out to verify the proposed method. The results show that the proposed strategy is effective. This paper can provide helpful guidance for the design of automated surface adjustments for large telescopes.

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Section: Methods B: Adjustment To the Best Fitting Locationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Surface adjustment strategy for a large radio telescope with adjustable dual reflectors

Lian

Wang

Xue

et al. 2019

IET Microwaves, Antennas & Propagation

Self Cite

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“…Reflector antennas are widely used in communication, radar, radio astronomy, and other applications . Surface errors are inevitable during operation because of structural inaccuracies, such as random machining errors and grid discretization errors, and exterior loads, such as gravity, temperature, and wind, and their effects on reflector's electrical performance have been deeply researched. However, with the development of reflector antenna with larger aperture and higher precision, it is well known that due to the difficulty of body machining using existing processes, a large reflector is usually composed of numerous small panels, such as the Effelsberg 100‐m Radio Telescope with 17 rings of panels and 2352 total panels, as shown in Figure .…”

Section: Introductionmentioning

confidence: 99%

Effects of reflector antenna panel installation errors on average power pattern

Lian

Wang

et al. 2019

Int J RF Microw Comput Aided Eng

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A large reflector antenna generally consists of several rings of panels and panel installation errors (PIEs) are inevitable during the panel installation process. In this paper, a mathematical model is developed to analyze the effects of PIEs on reflector's average power pattern. Whether for the PIEs of each ring of panels or for the PIEs of all the panels for the whole reflector, the proposed model can be used to calculate the average power pattern with the root-meansquare value of the PIEs, and its correctness is demonstrated by the results calculated by Monte Carlo simulation. For a given paneled reflector, the peak gain losses and the first side lobe level increments caused by different PIEs for the whole reflector are presented. Then, through an analysis for each ring of panels, including the effects of different amplitude aperture distribution functions and different ratios of focal length to diameter (F/D ratios), the results clearly show that the PIEs of the panels for different rings have different effects on the reflector's average power pattern, and valuable results are obtained. The derived results will greatly benefit the panel installation and adjustment of large reflector antennas. K E Y W O R D S average power pattern, panel installation error (PIE), reflector antenna

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“…An antenna dynamic model was introduced to analyze the influence of the deformation of different structures on the pointing error. The result revealed that the pointing error caused by the flexible deformation of the antenna cannot be ignored [13]. Using the beam waveguide system, a fast active compensation structure was designed, and through the optimized selection of the amplification factor, it is possible to quickly compensate for the pointing error caused by wind disturbance [14].…”

Section: Introductionmentioning

confidence: 99%

A Correction Method of Estimating the Pointing Error for Reflector Antenna

Zhang

Huang

Liang

et al. 2018

Shock and Vibration

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The pointing error caused by the structural deformation of large reflector antennas has become the most challenging problem of antenna servo control. Especially with the increase of the antenna diameter and the working frequency, environmental loads not only make the structure deformation more obvious, but also make the pointing accuracy influenced by deformation more sensitive. In order to solve this problem, accurately estimating the pointing error caused by the structural deformation is the key. Based on the dynamic model of antenna structure and the analyzing model of pointing error, using the displacement information of sampling points on reflector, this paper proposes a correction method to achieve the purpose of accurately estimating the pointing error caused by the structural deformation. Using a 7.3-m Ka band antenna, the results show that the antenna maximum pointing error in theoretical model calculation is 0.0041 ∘ at 10m/s wind speed condition; however, the corrected pointing error would be about 0.0054 ∘ with considering the modeling error. After compensating the controller, the pointing error could be reduced to only 0.0008 ∘ and the performance of antenna pointing was improved.

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A Compensator for Large Antennas Based on Pointing Error Estimation Under a Wind Load

Cited by 16 publications

References 13 publications

Surface adjustment strategy for a large radio telescope with adjustable dual reflectors

Surface adjustment strategy for a large radio telescope with adjustable dual reflectors

Effects of reflector antenna panel installation errors on average power pattern

A Correction Method of Estimating the Pointing Error for Reflector Antenna

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