As the lightwave passing through the atmosphere, the light’s path is not the uniform linear motion as well as the path has been bent, which causes the atmospheric refractive error of lightwave. As usual, two photoelectric theodolites are used to supply data for refractive error calculation. In the case of one photoelectric theodolite in the same time or the same area, the calculation method above is not suitable. This article proposes the calculation method of atmospheric refractive error based on single photoelectric theodolite which needs radar ranging to the flight target. First, station coordinate system is built and the station of photoelectric theodolite should be transformed to the system as well as the station of radar. Second, the original geocentric distance should be cut to L levels by lightwave refraction index from the station of photoelectric theodolite and the apparent distance between photoelectric theodolite and flight target is calculates. Third, the calculated geocentric distance should be cut to L levels by lightwave refraction index and the geocentric angle between photoelectric theodolite and flight target is calculated. At last, both the real elevation angle of photoelectric theodolite to the flight target and lightwave’s atmospheric refractive error are calculated by formula of elevation angle. The calculation method of atmospheric refractive error in this article only uses data of single photoelectric theodolite, as well as definite integral formulas of both apparent distance and geocentric angle are optimized, by which more accuracy error calculation of lightwave’s atmospheric refraction can be achieved.
Accuracy Measurement on aerial track of moving target is one of the major target for photoelectric theodolite, which target is solved by angle intersection algorithm of two-stations. For analyzing the accuracy and the photoelectric theodolite of the angle intersection measurement, this paper simulated 6 aerocrafts’ tracks. L,K algorithms of coplanar rendezvous and MLE algorithms of non-uniplanar intersection were used to measure aerocrafts’ tracks. The measurement result was relative analyzed with simulation track in angle intersection, then the L,K ,MLE algorithm’s applicability was fixed. One aerocraft track of simulation was chosen to measure by MLE algorithm in different station-setting conditions. The measurement error was compared in intersection angle, azimuth angle, pitching angle, baseline length, station location. And the relation between the conditions and measurement accuracy of tracks was fixed. Also the condition of station-setting was fixed. The work above has directive significance in the intersection algorithm choice and station-setting later.<p> </p> Measurement elements of optical equipment are teams of A, E, which is shorten as nAE. The nAE is belong to angle intersection measurement mechanism . The optical equipment usually supplies angle information only, two-stations theodolites or n-station theodolites are used in solid intersection measurement, and spacial coordinate of aerocraft is fixed . This method is called angle intersection measurement. This article simulated 4 aerocrafts tracks, and used 3 algorithms above to measure the tracks . The measurement result was relative analyzed with simulation tracks in intersection angle, and the L, K, MLE algorithm’s applicability was fixed .<p> </p> Usage of photoelectric theodolite faces the problem of station-setting, and the station-setting directly influences the measurement accuracy of track . This article chooses one aerocraft track to measure by MLE algorithm in different condition of station-setting. The measurement error was relative analyzed in intersection angle, azimuth angle, pitching angle, baseline length and station location, by which the relation between measurement accuracy and 5 conditions was fixed. The condition of station-setting was fixed on the base.
Most aircrafts is driven by chemic energy which is released in the combustion process. For improving the capability of engine and controlling the running on-time, the processes of fuel physics and chemistry need to be analysis by kinds of high quality sensor. In the research of designing and improving the processes of fuel physics and chemistry, the concentration, temperature and velocity of kinds of gas in the combustor need to be detected and measured. In addition, these engines and research equipments are always in the harsh environment of high temperature, high pressure and high speed. The harsh environment needs the sensor to be high reliability, well repetition, no cross- sensitivity between gases, and the traditional measurement system can’t satisfy the metrical requirement well.<p> </p> Tunable diode laser absorption spectroscopy (TDLAS) analytic measurement technology can well satisfy the measurement in the harsh environment, which can support the whole measurement plan and high quality measurement system. Because the TDLAS sensor has the excellence of small bulk, light weight, high reliability and well specifically measurement, the TDLAS measurement technology has wide prospects.<p> </p> Different from most measurements, only a beam of laser can be pass through the measured environment by TDLAS, and the measurement equipment needn’t be set in the harsh environment. So, the TDLAS equipment can’t be interrupted by the measured equipment. The ability of subsistence in the harsh environment is very valuable, especially in the measurement on the subject of aerospace with environment of high speed, combustion and plasma. This paper focuses on the collecting the articles on the subject of oxygen detection of TDLAS. By analyzing the research and results of the articles, we conclude the central issues, difficulties and results. And we can get some instructive conclusions.