A New Triangulation Algorithm for Positioning Space Debris

A single electro-optical (EO) sensor used in space debris observation provides angle-only information. However, space debris position can be derived using simultaneous optical measurements obtained from two EO sensors located at two separate observation sites, and this is commonly known as triangulation. In this paper, we propose a new triangulation algorithm to determine space debris position, and its analytical expression of Root-Mean-Square (RMS) position error is presented. The simulation of two-site observation is conducted to compare the RMS positioning error of the proposed triangulation algorithm with traditional triangulation algorithms. The results show that the maximum RMS position error of the proposed triangulation algorithm is not more than 200 m, the proposed triangulation algorithm has higher positioning accuracy than traditional triangulation algorithms, and the RMS position error obtained in the simulation is nearly consistent with the analytical expression of RMS position error. In addition, initial orbit determination (IOD) is carried out by using the triangulation positioning data, and the results show that the IOD accuracy of two-site observation is significantly higher than that of the single-site observation.

Analysis of the Rotor Magnetomotive Force of Built-In Radial Permanent Magnet Generator for Vehicle

Permanent magnet generator (PMG) for vehicles has attracted more and more attention because of its high efficiency, high power density, and high reliability. However, the weak main air-gap magnetic field can affect the output performance and the normal use of electrical equipment. Aiming at the problem, this paper took the rotor magnetomotive force (MMF), the direct influencing parameter of the main air-gap magnetic field, as the research object, deduced the analytical expression of rotor MMF of the built-in radial PMG in detail, and analyzed its main influencing factors in analytical expression, including the permanent magnet steel (PMS) material, the thickness of PMS in magnetizing direction, the vertical length of the inner side of PMS, and the effective calculation length of PMS. Based on this, the rotor parameters were optimized to obtain the best values. After that, the finite element simulation and prototype test of the optimized generator were carried out. The comparative analysis results showed that the optimized rotor parameters could effectively improve the rotor MMF and optimize the output performance of the generator.

Noise factor and reception bandwidth in optoacoustical GW antenna

An expression has extracted from the OGRAN project theory, which provides connection between numerical values of noise factor F and achieved displacement resolution and antenna’s threshold signal in metric variations. Noise factor and “reception bandwidth” connects across displacement resolution. There is defined analytical expression and numerical value for design displacement resolution (sensitivity) on the base intention F = 1. It has appeared that the extracted analytical expression for readout resolution does not correspond to applied Pound-Drever-Hall technique and AURIGA circuitry. This requires an improvement in theoretical design. The achieved resolution value 2·10−15 cm/Hz1/2 is matched to the value for metric sensitivity in pulse hmin ≃ 10−18, which is 15 dB higher than the thermal sensitivity limit.

Determination of Optimal Angles of Solar Panels for Satisfied Time Intervals on the Territory of Ukraine

The results of determining the optimal angles of inclination to the horizon of flat solar panels with a constant orientation to the south are presented. An analytical expression is obtained, which describes the dependence of the optimal angles for time intervals symmetric with respect to July 1 on their duration in months. The parameters of this expression are set for several cities of Ukraine. A method for determining (estimating) the optimal angles of inclination for arbitrary time intervals, except for those in the range of November-February. It was shown that for symmetric relatively summer (July 1) and relatively winter (January 1) intervals there is a certain functional relationship between the value of the optimal angle βopt. and the duration of intervals in months. For summer and winter months, these dependences are described by polynomials of the 2nd order, which makes it possible to determine βopt. for arbitrary time intervals of the mentioned symmetry.