The fabricated fiber had a loss of 0.9 dB/m at 532 nm.Figure 2.Scanning Electron Microscope (SEM) image of the soft glass MOF used for these experiments. The central, structured region of the fiber was made from F2HT glass, view more and the cladding from F2 glass.4.?System CharacterizationInitial characterization was performed on the MOF using two diffe
The sun sensor is one of the most important devices for satellites. The early sun sensors were mainly sun appearance sensors and analog sun sensors [1]. With the development of space technology in recent years, requirements for sun sensors has Inhibitors,Modulators,Libraries been extended to a large field of view and high accuracy levels. The traditional design and implementation methods cannot meet these the requirements, so the single-axis digital sun sensor [2] appeared, with an accuracy of better than 0.
1��. Two of the same single-axis digital sun sensors mounted vertically Inhibitors,Modulators,Libraries can constitute a conventional two-axis sun sensor. Such digital sun sensors are widely used currently.Array image sensors such as CCD or CMOS and so on have been widely applied in space science. The array image sensor-based sun sensor is currently a research focus [3]. This kind of equipment is of high accuracy, high anti-interference. The aperture of sun sensors can be divided into single-aperture [as shown in Figure 1(a)] and multi-aperture [as shown in Figure 1(b)]. Compared with the traditional linear array sun sensor, the accuracy of a single-aperture sun sensor is increased, however, since only one Inhibitors,Modulators,Libraries spot is used Inhibitors,Modulators,Libraries in the system, image utilization rate is low, so it is difficult to further enhance its accuracy.
The Italian Galileo Avionica Company has developed a single-aperture sun sensor, named Smart Sun Sensor [4].Figure 1.(a) single-aperture sun sensor (b) multi-aperture sun sensor.Compared Anacetrapib with the single-aperture sun sensor, a multi-aperture sun sensor has the following three advantages:Accuracy: as the single-aperture sun sensor accuracy depends mainly on the positioning accuracy of the sun spot, and its pointing accuracy is only about 0.03�� ,but for the multi-aperture sun sensor the accuracy of the sun spot location centroid is proportional to the square root of the number of apertures. Assuming that the pointing accuracy of a single hole ��, and hole arrays of N �� N, then the final pointing accuracy is ��/N, This shows that multi-aperture can greatly improve the accuracy of the sun sensor.
Reliability: for the single-aperture sun sensor there is a very deadly excellent validation danger: lack of reliability! When the hole is blocked or partially blocked, the accuracy will be greatly affected or even cause the system to lose function. For the multi-aperture sun sensor, the distribution of the image sensor area is relatively large, so even when part of the holes are completely blocked, using a reasonable method, the system still be able to guarantee the normal operation.