Showing papers by "State Bureau of Surveying and Mapping published in 2013"

Triple linear-array image geometry model of ZiYuan-3 surveying satellite and its validation

Abstract: ZiYuan-3 (ZY-3) surveying satellite is China's first civilian high-resolution stereo mapping satellite. The satellite's objective is oriented towards plotting 1:50,000 and 1:25,000 topographic maps. Compared with plotting using foreign commercial mapping satellite imagery, establishment of the image geometry model is the core technical problem for different products and various applications of ZY-3 surveying satellite. This article analyses key problems of high-precision geometry processing based on the overall design, and proposes ZY-3 surveying satellite image geometry model with the technology of virtual CCD line-array imaging. In addition, this article utilises the first orbit imagery of ZY-3 satellite with coverage of Dalian region in Liaoning Province, and produces forward, backward and nadir camera calibrated products. Different ground control points are selected for the block adjustment experiment and the digital surface model (DSM), digital ortho-map (DOM) are generated. The accuracy is validated...

A scale-adaptive DEM for multi-scale terrain analysis

Abstract: A scale-adaptive digital elevation model (S-DEM) method is proposed for multi-scale terrain analysis using a single high-resolution digital elevation model (DEM) database The motivation is to construct a DEM that is self-adaptive to a given scale of an application, rather than letting the application fit into the built-in scale of the DEM The method is based on an adaptive compound point extraction (CPE) algorithm that extracts surface ‘significant points’ from a high-resolution DEM according to their degree of importance (DOI) to the scale of an application A data structure can be established to match the demand from an application at a coarser scale Based on the data structure, a triangulated irregular network (TIN) model can be generated to support the terrain analysis at the desired scale The aim of the S-DEM is to support multi-scale applications in three aspects, namely, ‘one database for all scales and scale-adaptive’ (ie matching any application scale using a single high-resolution DEM), ‘c

Explicitly computing geodetic coordinates from Cartesian coordinates

Abstract: This paper presents a new form of quartic equation based on Lagrange’s extremum law and a Groebner basis under the constraint that the geodetic height is the shortest distance between a given point and the reference ellipsoid. A very explicit and concise formulae of the quartic equation by Ferrari’s line is found, which avoids the need of a good starting guess for iterative methods. A new explicit algorithm is then proposed to compute geodetic coordinates from Cartesian coordinates. The convergence region of the algorithm is investigated and the corresponding correct solution is given. Lastly, the algorithm is validated with numerical experiments.

Study on artificial neural network combined with multispectral remote sensing imagery for forest site evaluation

Abstract: Multispectral remote sensing data containing rich site information are not fully used by the classic site quality evaluation system, as it merely adopts artificial ground survey data. In order to establish a more effective site quality evaluation system, a neural network model which combined remote sensing spectra factors with site factors and site index relations was established and used to study the sublot site quality evaluation in the Wangyedian Forest Farm in Inner Mongolia Province, Chifeng City. Based on the improved back propagation artificial neural network (BPANN), this model combined multispectral remote sensing data with sublot survey data, and took larch as example, Through training data set sensitivity analysis weak or irrelevant factor was excluded, the size of neural network was simplified, and the efficiency of network training was improved. This optimal site index prediction model had an accuracy up to 95.36%, which was 9.83% higher than that of the neural network model based on classic sublot survey data, and this shows that using multi-spectral remote sensing and small class survey data to determine the status of larch index prediction model has the highest predictive accuracy. The results fully indicate the effectiveness and superiority of this method.

Cloud detection on HJ-1B data based on multispectral analysis

Abstract: Cloud detection is absolutely necessary in the processing of satellite remote sensing data.Through analyzing spectral characteristics of cloud and typical objectives and integrating the channel characteristics of HJ-1B,a cloud detection algorithm for HJ-1B was proposed based on multispectral analysis in the paper.Taking it into account the different types of underlying surface,it gradually built a cloud detection mask by choosing suitable band combination.This method was applied to remove cloud pixels from many different images.The results showed that this approach could detect cloud pixels over different periods and different scenes successfully,which would promote the use of HJ-1B data and improve the precision of image classification.

Galileo E5 Signal Acquisition and Tracking Based on a Wide-Band Customized Universal Peripheral N210 Platform

Abstract: GNSS navigation has its own advantages which make researchers focus on how to effectively receive and process GNSS signals. This typically needs to utilize flexible specialized radio frequency front-ends, and we need to investigate novel software solutions. Due to the good performance of the Galileo E5 signal, the study of its acquisition, tracking and multipath mitigation has become increasingly significant. This paper has developed a customized 100MHz wide-band GNSS front-end. Three wide-band datasets of Galileo E5 signal were collected for case study. Final acquisition and tracking results of Galileo E5a signal successfully verified this customized RF front-end usability. It offers great potential for further studying the multi-constellation GNSS compatibility and interoperability to achieve high accuracy and continuity of GNSS navigation.