Optimal surface adjustment of Haystack antenna

Zarghamee, Mehdi S.; Antebi, Joseph; Kan, Frank W.

doi:10.1109/8.366355

Cited by 9 publications

(6 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where ρ h and ρ z are the best-fitting half-path-length error vectors at the horizon position and the zenith position, respectively. For convenience, the ''adjustment'' described in this paper refers to adjustment of the half-path-length errors, which has a simple relationship with the panel settings [15], [17].…”

Section: Formulas and Derivation A Surface Adjustment In Generalmentioning

confidence: 99%

See 1 more Smart Citation

Novel Worst-Case Surface Accuracy Evaluation Method and Its Application in Reflector Antenna Structure Design

et al. 2019

View full text Add to dashboard Cite

In order to ensure the electrical performance of the reflector antenna, the surface accuracy constraint need to be satisfied during the structure design. Different calculating methods can get different accuracy values, then influence the difficulty of antenna structure design. Therefore, the evaluation method for antenna surface accuracy is of vital importance. In this paper, the traditional evaluation procedure is first reviewed. This method has been successfully used in structure design of many large antennas, but based on our analysis, this method is sub-optimal. For this reason, a new accuracy evaluation method is introduced, which can get the optimal worst-case surface accuracy. Both quantitative analysis and numerical example of a 110 m radio telescope show that this method can improve the worst-case accuracy effectively. The structural optimization of an 8 m antenna, as a test problem, is also discussed and the results are given.

show abstract

Section: Formulas and Derivation A Surface Adjustment In Generalmentioning

confidence: 99%

“…2. This procedure is very effective and has been widely used in the design of antenna structure [15][16][17][18][19][20], such as many famous telescopes -IRAM 30 m, SRT 64 m, HUSIR 37 m, QTT 110 m etc.…”

Section: Introductionmentioning

confidence: 99%

Novel Worst-Case Surface Accuracy Evaluation Method and Its Application in Reflector Antenna Structure Design

et al. 2019

View full text Add to dashboard Cite

show abstract

“…These formulas are verified by the ray tracing method in Mathcad (Lamb & OVRO 2001). Based on these simple formulas, the peak gain of the Cassegrain antenna can be obtained with the subreflector position adjustment and the relationship between the surface accuracy and beam position of the Cassegrain antennas is presented in Zarghamee (1982); and optimal surface adjustment and upgrade of the Haystack antenna (Zarghamee et al 1995) have received useful guidance. Through the above-mentioned cases, it seems natural to use these simple formulas to determine the deformations of the subreflector surface and compensate.…”

Section: Deformations Of the Shaped Subreflectormentioning

confidence: 99%

B-spline surface fitting and simplified GO/PO analysis of subreflector correction for large Cassegrain antenna distortion compensation

Ban

Wang

Feng

et al. 2018

Res. Astron. Astrophys.

View full text Add to dashboard Cite

The main surface of a large Cassegrain antenna consists of a large number of panels. There are inevitably random and systematic errors which will degrade the antenna pattern and limit its applicability when working at high frequencies. Correcting the subreflector surface is difficult to describe by a global expansion effectively with a small amount of data. This paper presents a simple and clear way for correcting the subreflector surface of a large Cassegrain antenna for achieving such compensation. The advantage of the method is that the geometrical optics (GO) analysis is extremely simplified by the concept of equivalent prime-focus paraboloid, and corrected deformations of the subreflector surface are determined by simple formulas which represent the relationship between distortions of the subreflector surface and phase of the main surface current. The final shape of the subreflector surface is represented by a B-spline surface. To obtain a satisfactory antenna pattern with the simplest subreflector surface, the optimal number of B-spline patches are searched by particle swarm optimization (PSO). The shaping process is verified by compensating a 22-m Cassegrain antenna whose main reflector has 96 panels. The results are satisfactory and demonstrate the simplicity and effectiveness of the approach.

show abstract

“…Holography uses a smaller dish (that is assumed to be perfect) pointed at a satellite beacon (typically a geosynchronous satellite to avoid the need for tracking) as a reference signal. The antenna under test then raster scans across the source to sample the beam [21,22]. Correlations with the reference signal are used to recover the absolute phase errors, and inverse Fourier transforms are used to recover the aperture wavefront error, which feeds back to required surface adjustments to make corrections.…”

Section: Introductionmentioning

confidence: 99%

Systematic Radio Telescope Alignment Using Portable Fringe Projection Profilometry

Berkson,

Hyatt,

Julicher

et al. 2024

Nanomanuf Metrol

View full text Add to dashboard Cite

In 2019, the Event Horizon Telescope (EHT) released the first-ever image of a black hole event horizon. Astronomers are now aiming for higher angular resolutions of distant targets, like black holes, to understand more about the fundamental laws of gravity that govern our universe. To achieve this higher resolution and increased sensitivity, larger radio telescopes are needed to operate at higher frequencies and in larger quantities. Projects like the next-generation Very Large Array (ngVLA) and the Square-Kilometer Array (SKA) require building hundreds of telescopes with diameters greater than 10 ms over the next decade. This has a twofold effect. Radio telescope surfaces need to be more accurate to operate at higher frequencies, and the logistics involved in maintaining a radio telescope need to be simplified to support them properly in large quantities. Both of these problems can be solved with improved methods for surface metrology that are faster and more accurate with a higher resolution. This leads to faster and more accurate panel alignment and, therefore, a more productive observatory. In this paper, we present the use of binocular fringe projection profilometry as a solution to this problem and demonstrate it by aligning two panels on a 3-m radio telescope dish. The measurement takes only 10 min and directly delivers feedback on the tip, tilt, and piston of each panel to create the ideal reflector shape.

show abstract

Optimal surface adjustment of Haystack antenna

Cited by 9 publications

References 7 publications

Novel Worst-Case Surface Accuracy Evaluation Method and Its Application in Reflector Antenna Structure Design

Novel Worst-Case Surface Accuracy Evaluation Method and Its Application in Reflector Antenna Structure Design

B-spline surface fitting and simplified GO/PO analysis of subreflector correction for large Cassegrain antenna distortion compensation

Systematic Radio Telescope Alignment Using Portable Fringe Projection Profilometry

Contact Info

Product

Resources

About