Optical Theodolite Based Rationality Check of Measurement Data From Pulse Radar

Theodolite and radar are important measurement and control devices in aviation, aerospace and other fields. In order to make sure the tracking measurement and navigation control of aircraft and spacecraft safely, this paper creatively proposes a novel method to check the rationality of the three-dimensional measurement data (distance, azimuth and pitch angle) of the pulse radar by using the two-dimensional measurement data (azimuth and pitch angle) of the optical theodolite. Specifically, three different rationality checking functions are constructed for the three different cases of unreliable ranging channel, unreliable angle measuring channel and unreliable ranging and angle measuring channels, and are used for the rationality checking of radar data in the above three cases respectively. Simulation results show that the correct rate is more than 95% as long as the data measured by optical theodolite are reliable.

Thermodynamic model for a pilot balloon

In the early part of the 20th century, tracking a pilot balloon from the ground with an optical theodolite was one of the few methods that was able to provide information from the upper air. One of the most significant sources of error with this method, however, was involved in calculating the balloon height as a function of time, a calculation dependent on the ascent rate which was traditionally taken to be constant. This study presents a new thermodynamic model which allows us to compute the thermal jump between the surrounding environment and the lifting gas as a function of different parameters such as the atmospheric temperature lapse rate or the physical characteristics of the balloon. The size of the thermal jump and its effect on the ascent rate is discussed for a 30 g pilot balloon, which was the type used at the Ebro Observatory (EO) between 1952 and 1963. The meridional and zonal components of the wind profile from ground level up to 10 km altitude were computed by applying the model using EO digitized data for a sample of this period. The obtained results correlate very well with those obtained from the ERA5 reanalysis. A very small thermal jump with a weak effect on the computed ascent rate was found. This ascent rate is consistent with the values assigned in that period to the balloons filled with hydrogen used at the Ebro Observatory and to the 30 g balloons filled with helium used by the US National Weather Service.

Rationale for a geodesic monitoring system using a variable length rail

The purpose of improvement of the accepted geodetic decisions concerning the program of geodetic monitoring of highrise buildings of a difficult design taking into account conditions of the increased danger of a construction site Method. Execution of geodetic observations of subsidence of a multi-storey building under the condition of joint use of invar rail and rail of variable length according to the leveling program of the first class. Comparative observations of the displacement of the structure using a high-precision optical theodolite and an electronic total station. Results. Improved methods and geodetic accessories for determining the plan-height deformations of buildings erected in difficult geological conditions. . Scientific novelty. Search and collection of initial information, analysis of normative documentation on the organization of geodetic monitoring of deformation of engineering structures are carried out. Methods for determining the deformations of engineering structures are analyzed. The advantages of class I geodetic observations with the help of accurate optical geodetic instruments over other methods are proved. Comparative studies of the accuracy of a modern electronic total station and a high-precision optical theodolite were performed in the field. The planned and height dynamics of deformation processes of building structures during the construction period and at the initial stage of operation are determined. A comparative analysis of the results of determining the deposition of the pile field by methods of loading piles with hydraulic jacks and the load from the actual mass of the aboveground part of the house. It is established that the largest deformations of the structure occur at the initial stage of construction and gradually fade after its completion. The calculation of the accuracy of geodetic works with the joint use of traditional invar rails and rails of new design. Practical value. The organization and conduct of geodetic works to monitor the deformation processes of multi-storey buildings on the developed technology of precision leveling contributes to the timely establishment of maximum allowable values of deformation, risk prevention, to preserve the safety of residential complexes under difficult geological conditions. A new design of the leveling rail and a leveling technique with the simultaneous use of a standard invar rail and developed by the authors have been developed. Improved method of linear-angular measurements for monitoring the planned deformations of buildings.

Analysis on Dynamic Accuracy Appraisal for Optical Theodolite

A method of dynamic accuracy appraisal for optical theodolite is proposed in the paper. Its mathematical model and solution method are deduced. Then, this appraisal method is verified through the simulation. The results suggest there are many advantages in accuracy and reliability to appraise dynamic accuracy of optical theodolite with the method proposed in the paper. In addition, the method is easier and conducive to engineering applications.

Study on the Multi-Optical Theodolites Positioning Method Based on Function Restriction

Aiming at the shortcoming of the classical method of optical theodolite projection intersection named ́R ́ method and traditional data fusion method named point-by-point EMBET method, this paper advances the function restriction EMBET method which is based on multi-optical theodolites. Comparing with the three methods by simulation experiment, it demonstrates that the function restriction EMBET method has higher positioning accuracy and stronger practicability than two traditional methods. Furthermore, this method supplies the important reference value for engineering application.