A new method of optical horizontal reference measurement based on CCD sensor is presented . The designs of circuits for measuring based on 89C51 are analysed in detail.

In order to solve the problem existing in the measurement of the magneticfield about thewarshipsin the degaussing station,the magnetic field data of the warship standard points iscalculated from the ones of the basis points by the method of two-dimensional data interpolation.

This vitrual instrument can measure the frequency of passive quartz crystal oscillator using the output 1PPS signal of GPS module as the time standard and accomplish the time synchronization and distance measurement using the GPS signals.

The paper presents the hardware composition, the software function of the reference measuring system for the fire control radar, analyzes the accuracy, gives out the model of coordinate conversion and the method of the performance index evaluation for the fire control radar.

Development and evaluation of a candidate reference measurement procedure for the determination of testosterone in human serum u

A candidate reference measurement procedure for total testosterone in human serum involving isotope dilution (ID) coupled with liquid chromatography/tandem mass spectrometry (LC/MS/MS) has been developed and critically evaluated.

Evaluation of resistivity data comprises modified double mass calculations versus data from reference measurement sites, which enables detection of contamination although it influences the resistivity less than the natural seasonal variations.

The results exhibit very good agreement with a reference measurement performed with a fast FTIR Spectrometer.

These data were compared to a reference measurement (saturable detector sampling scheme); the results show that the interarrival time weighting method compares favorably with the reference measurement under the present conditions.

Two-photon lasers and laser amplifiers are studied by using the rate equations. The steady solution is obtained and its stability is analysed. The time evolution of large deviation from the steady solution is studied by using computer simulation. The population inversion and the trigger input must exceed certain thresholds to operate a two-photon laser. The method for producing giant-pulse is discussed. The possibility of building a pratical two-photon laser is analysed basing on the known data. A Doppler-i'ree...

Two-photon lasers and laser amplifiers are studied by using the rate equations. The steady solution is obtained and its stability is analysed. The time evolution of large deviation from the steady solution is studied by using computer simulation. The population inversion and the trigger input must exceed certain thresholds to operate a two-photon laser. The method for producing giant-pulse is discussed. The possibility of building a pratical two-photon laser is analysed basing on the known data. A Doppler-i'ree two-photon laser needs much lower threshold but much more serious frequency matching among the atom system, cavity and the trigger input. Such a Doppler-free two-photon laser could find applications in laser spectroscopy and in the accurate metrology. Two-photon laser amplifiers distort the input waveform seriously. This distortion depends strongly on the input intensity.

The basic principle and method of measuring the antenna excess noise temperature Tas by using the radio stars as calibration are presented in this paper. In this method, the antenna noise temperature TAN is used as a standard of calibration when the antenna points at sky. It was found that the results of measurement using this method agree with that obtained by using liquid nitrogen at low and normal ambient temperature as standard of calibration. The method has advantage of more simplicity of the measurement...

The basic principle and method of measuring the antenna excess noise temperature Tas by using the radio stars as calibration are presented in this paper. In this method, the antenna noise temperature TAN is used as a standard of calibration when the antenna points at sky. It was found that the results of measurement using this method agree with that obtained by using liquid nitrogen at low and normal ambient temperature as standard of calibration. The method has advantage of more simplicity of the measurement and equipment. The total error of antenna excess noise temperature obtained by this method could be estimated to be ±3%. The error of antenna gain measured is about±0.3 dB.

A measuring method of five-freedom kinematic errors of a moving table along one axis is introduced which employs two laser beams as a plane datum. A mathematical model based on the basic principles of rigid body kinematics is also given. All error computation formulas obtained are simple in form and easy to handle. This method is suitable for real-time, in-situ kinematic accuracy analysis and compensation.