High-Precision Simulation of Onboard Signal Receivers in Global Navigation Systems

Aircrafts and spacecrafts that make use of global navigation satellite systems (GNSS) carry onboard signal receivers. The development of software for modeling the operation of such receivers is considered in this article. The plausible simulation of receiver operation is resolved into subsidiary problems. The formation of the satellites’ ephemeris data is important here. The proposed design approach is to develop an information system capable of monitoring the constellation of navigation satellites on the basis of the corresponding data files provided by different centers of GNSS analysis. The proposed approach is shown to be more effective than the available alternatives.     

Deep levels in the band gap of GaN layers irradiated with protons

Deep-level transient spectroscopy was used to study the parameters of deep levels in the band gap of epitaxial n-GaN layers after irradiaton of the Schottky barriers with 1-MeV protons to a dose of 10¹² cm^?2. A deep level EP1 with an activation energy of 0.085 eV was introduced by irradiation into the upper half of the GaN band gap. The introduction rate of the corresponding defect was found to depend on the bias voltage applied to the Schottky barrier during irradiation.     

Determination of the concentration of etching solution components containing nitric and hydrofluoric acids

Translated from Steklo i Keramika, No. 9, pp. 30–31, September, 1991.     

A method of overlapping periodic compensation of atmospheric background radiation

A method of detecting heat-generating objects in atmospheric background by means of an infrared radar set with broad field of vision based on the difference in the brightness amplitudes of the radiation from a point heat-generating object and the cold atmospheric background is set forth. An algorithm of a two-dimensional spatial filter that may be implemented by a computer program in the video processor of an infrared radar set is developed.     

Control Algorithm of the Angular Position of a Quadcopter Based on Statistical Analysis of Experimental Data

Russian Engineering Research - An algorithm is proposed for controlling the angular position of a quadcopter and establishing optimal (in terms of minimum time) orientation control in the absence...     

Improved Processing of Data from Micromechanical Sensors in a Universal Integrated Navigation System

Russian Engineering Research - Measures for more precise processing of primary information from micromechanical sensors in an integrated navigation system are considered. Algorithms are proposed...