This paper introduces the basic situation and performance of the upgraded CORS system based on the construction project of the continuous operating reference station system in Xi'an,the system functions,real-time positioning accuracy,post-processing po-sitioning accuracy,time and space availability and compatibility of the data center are tested.The results show that the system per-formance can meet the design requirements,in the coverage of the CORS site and the extension of a certain extent it can provide users with centimeter-level real-time positioning services.
In order to accurately analyze the monitoring data of highway subgrade settlement and predict the deformation trend in a cer-tain period of time in the future according to the current monitoring data,this paper combines the advantages of least square support vector machines(LSSVM)model and improved particle swarm optimization(IPSO)algorithm in data prediction and parameter opti-mization,build a new IPSO-LSSVM combined prediction model.The combined prediction model continuously optimizes the penalty factor C and kernel function parameters in LSSVM model through IPSO algorithm to avoid the problem of low prediction accuracy caused by the randomness of parameter selection.The effectiveness and superiority of the proposed model are tested by using the meas-ured settlement data of a highway subgrade.The results show that the LSSVM model optimized by IPSO algorithm has higher prediction accuracy and better stability,which can provide a certain reference value for deformation prediction.
Oblique photogrammetry is one of the new data acquisition methods for surveying and mapping.It can obtain the surface tex-ture information and geometric information that can not be obtained by conventional aerial photography,and can quickly build a 3D model.It has the advantages of real modeling,rich texture,high precision,quick production process,less personnel demand and low cost.This article adopts UAV oblique photography method and uses software to achieve 3D real scene modeling of the research area.The entire technology application process is studied,and the data quality is analyzed.The results show that UAV oblique photography technology has obvious advantages in the process of 3D model construction,and the model accuracy can meet the actual production re-quirements,which can provide strong technical support for surveying and mapping projects with high accuracy requirements.
This paper takes SOKKIA NET05AXⅡ measurement robot as the basic platform,combined with the actual needs of slope monitoring,and based on the principle of"the intersection of the corners behind the work base point + polar coordinate measurement of the monitoring point"to design and develop a slope safety online monitoring system.The overall framework,topological structure and business flow of the system are designed in detail,so as to solve the problems such as poor timeliness of data in slope monitoring and inability to monitor in bad weather;And analyze and study the principle and error source of polar coordinate measurement,and conclude that the main sources of error include measurement robot angle and distance measurement errors,as well as the slant distance and vertical angle between the measurement robot and the monitoring point.Then,through a slope monitoring project,comprehensive-ly verify the stability and accuracy of the online monitoring system,and use manual monitoring methods to recheck the automated mo-nitoring data.The results show that the monitoring data of the system is basically consistent with the results of manual review,which meets the requirements of regulation and slope safety monitoring.
Visual presentation and expression of deformation monitoring results can help professionals provide reliable assistance and decision-making,and play an active role in smart city planning,urban disaster monitoring and urban disaster early warning.This pa-per combines GPS and InSAR technology to monitor surface deformation in some areas of Datong city,Shanxi province,and integrates the 3D geospatial platform Cesium under the B/S architecture to realize the loading and display of large-scale monitoring data.At the same time,statistical analysis and visualization are carried out through charts and other methods.The online warning function is com-pleted through deformation threshold setting,and a multi-source,multi-scale,and multi-functional deformation monitoring platform is constructed.
