Measurement of Tracking Accuracy of Antenna Using Precise Geostationary Satellite Orbit

2011 ◽  
Vol 128-129 ◽  
pp. 616-619 ◽  
Author(s):  
Ye Jun Wang ◽  
Ai Wu Zheng ◽  
Yong Qiang Fu ◽  
Yong Qing Liu
Keyword(s):  
Electromagnetic Wave ◽  
Conventional Method ◽  
Satellite Orbit ◽  
Geostationary Satellite ◽  
New Method ◽  
Tracking Accuracy ◽  
Very High

The conventional method to measure the tracking accuracy of antenna is based on the boresight tower. But the accuracy of this method is not very high because the result is easy to be disturbed by reflecting electromagnetic wave from ground, surrounding buildings and terrains under low elevation in measuring. And a boresight tower and a lot of corresponding equipments are needed in this method. It costs both time and money. This paper presents a new method of using precise geostationary satellite orbit to measure the tracking accuracy. It is easy to operate. Moreover, the accuracy of this method is higher than the conventional one. The feasibility of the new method is validated in comparison with the conventional one, so it can be used in the construction and maintenance of ground stations.

Geostationary Satellite Orbit Analysis Program (OSOAP)

1986 ◽  
Author(s):  
G. HURT ◽  
H. NG ◽  
H. AKIMA ◽  
C. FILIPPI
Keyword(s):  
Satellite Orbit ◽  
Geostationary Satellite ◽  
Analysis Program ◽  
Orbit Analysis

scholarly journals Stellar magnetic imaging from spectropolarimetric data

1996 ◽  
Vol 176 ◽  
pp. 53-60 ◽  
Author(s):  
J.-F. Donati
Keyword(s):  
Small Amplitude ◽  
High Accuracy ◽  
Spectral Lines ◽  
New Method ◽  
Doppler Imaging ◽  
Magnetic Imaging ◽  
Active Stars ◽  
Surface Fields ◽  
Very High

In this paper, I will review the capabilities of magnetic imaging (also called Zeeman-Doppler imaging) to reconstruct spot distributions of surface fields from sets of rotationnally modulated Zeeman signatures in circularly polarised spectral lines. I will then outline a new method to measure small amplitude magnetic signals (typically 0.1% for cool active stars) with very high accuracy. Finally, I will present and comment new magnetic images reconstructed from data collected in 1993 December at the Anglo-Australian Telescope (AAT).

scholarly journals GPR Pulse Propagation Topography

2021 ◽  
Vol 36 (5) ◽  
pp. 596-602
Author(s):  
Veli Voipio
Keyword(s):  
Conventional Method ◽  
Ground Penetrating Radar ◽  
Pulse Propagation ◽  
New Method ◽  
Depth Range ◽  
Pulse Radiation ◽  
Ground Penetrating

In this article, I propose a new method for calculating and visualizing the pulse radiation within the depth range commonly used by Ground Penetrating Radar (GPR). The text describes the method and illustrates the propagation with several examples. One conventional method is also applied for a quick comparison. The method can be used to optimize GPR antennas and transmit pulse shapes.

scholarly journals Ultrasound assessed a new method of needle insertion at an angle of 90°to the apex of the sacral hiatus for caudal block in newborns: a randomized controlled study

2019 ◽  
Author(s):  
Shangyingying Li ◽  
Yanzhe Tan ◽  
Fei Yang ◽  
Lifei Liu ◽  
Shengfen Tu
Keyword(s):  
Failure Rate ◽  
Conventional Method ◽  
Local Anesthetic ◽  
Needle Insertion ◽  
New Method ◽  
Controlled Study ◽  
Minimal Risk ◽  
Caudal Block ◽  
Sacral Hiatus ◽  
Method Group

Abstract Background Caudal block is widely used in paediatric anaesthetic practice. Many angles for needle insertion were compared to find a optimal angle during caudal block with high successful caudal injection and minimal risk of complications. The aim of this study is to evaluate the safety and effectivity of a new method of needle insertion at an angel of 90°to the apex of the sacral hiatus for caudal block in newborns. Methods Sixty patients were included in our study, aged 0 to 28 days, posted for inguinal hernia surgery, randomly divided into two groups: a conventional method (CM) group and a new method (NM) group. In both groups, 1 ml∙kg-1 0.5% lignocaine at a rate of approximately 0.5 ml∙s-1 was given for caudal blocks after anaesthesia, and ultrasonographic observation of local anesthetic in the epidural space. Failure rate at the first attempt, puncture frequency, complications, and durations of block were recorded. Results The failure rate at the first attempt of caudal block were 16.7% in the conventional method group and 3.3% in the new method group (p<0.05). The mean time required (standard deviation) to perform needle insertion in the conventional method group was 2.6±0.5 minutes and in new method group 1.6±0.5 minutes (p<0.05). There were three cases aspirating the needle to find blood and one case to find cerebrospinal fluid in the conventional method group. The majority level which the local anesthetic reached are L1 by ultrasound imaging, 86.7% in the conventional method group and 83.3% in the new method group. Conclusion The study found that using the new method, the chance of performing a successful caudal injection can be increased, the time and the risk can be minimized compared to conventional technique. It is a safe and effective method.

Measurement of the Field Pattern of a Radio Telescope using a Geostationary Satellite

1980 ◽  
Vol 4 (1) ◽  
pp. 30-33 ◽  
Author(s):  
H. E. Green
Keyword(s):  
Fixed Point ◽  
Point Source ◽  
Conventional Method ◽  
Radio Telescope ◽  
Radio Astronomy ◽  
Geostationary Satellite ◽  
Field Pattern ◽  
High Angle ◽  
Ground Effects

The conventional method of measuring the radiation diagram of an antenna is to rotate it in the field produced by a fixed point source located in its Fraunhofer zone (Hollis et al. (1970)). With the very large antennas typically used in radio astronomy this presents difficulties. For example, to measure the 64 m telescope at ANRAO, Parkes at frequencies in the OH transition lines band (1.6-1.7 GHz), the source, to be located in the Fraunhofer zone, must be located at least 50 km away and then at a sufficiently high angle to allow measurements free from ground effects to be made. Clearly there are no terrestrial means to accomplish this.

Method of Examining Surface Cracks on Monocrystalline Silicon

2007 ◽  
Vol 364-366 ◽  
pp. 920-924
Author(s):  
Feng Zhou Fang ◽  
Yu Chan Liu ◽  
Qing Xiang Pei ◽  
Xiao Tang Hu
Keyword(s):  
Conventional Method ◽  
Simple Approach ◽  
Monocrystalline Silicon ◽  
New Method ◽  
Silicon Surfaces ◽  
Surface Cracks ◽  
Absorbed Energy ◽  
Nano Indentation ◽  
Micro Cracks

A new method on examining the micro cracks of monocrystalline silicon during nano indentation is proposed. It is established based on a study of the increasing rate of absorbed energy in nano indentation. This method provides a simple approach in understanding whether cracks on the silicon surfaces occur, while it is tedious in conventional method.

Charles Glover Barkla, 1877-1944

1947 ◽  
Vol 5 (15) ◽  
pp. 341-366 ◽  
Keyword(s):  
Electromagnetic Wave ◽  
Atomic Number ◽  
Chemical Element ◽  
Three Dimensional ◽  
Atomic Weight ◽  
New Method ◽  
X Rays

The name of Barkla will always be distinguished on account of his fundamental researches on Rontgen rays. In 1905 he made the discovery that scattered X-rays are polarized, but only to a certain degree. He also established the fact that each chemical element can radiate Röntgen rays having properties characteristic of that element, and in this way he anticipated the assignment to each element of an ‘atomic number’, the number being, in general, about one-half the atomic weight. For these discoveries he was admitted a Fellow of the Society in 1912, his investigations having resulted in the most important additions to our knowledge of the Röntgen rays since their discovery. Barkla consistently adopted the electromagnetic wave or pulse theory of the nature of the rays. At the end of the year 1912, von Laue put forward his theory of the diffraction of X-rays by transmission through a crystal regarded as a three-dimensional grating, thus introducing an entirely new’ method of investigation.

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