The quality analysis of GNSS satellite positioning data
Focused on the Beidou satellite system (BDS), dual satellite system (GPS/GLONASS) and three satellite system (BDS/GPS/GLONASS), the parameters influencing the quality of static and real-time dynamic positioning date of the GNSS systems, such as the multipath effect, ionospheric delay, data utilization rate and signal-to-noise ratio, number of satellites and accuracy factor PDOP value, have been comparatively analyzed in this paper. The results of tests have shown that compared to the single satellite system BDS the average multipath errors (mp1 and mp2) of multi satellite system fusion decreased by 18 and 8% respectively, due to the increase in the number of visible satellites in multi-satellite fusion, it is possible to compensate each other to a certain extent, thus weakening the influence of the multipath effect on the positioning results. When the cut-off angle is greater than 40°, the single system cannot meet the need of navigation and positioning, however having more visible satellites than the single system it is possible for multi satellite system fusion to maintain lower and more stable PDOP value for high precision positioning services.
Implementation and Verification Analysis of the Software of GNSS Data Quality Check
With the development of global navigation satellite system,it is a trend to receive satellite siginals from muti-systems for one receiver.At the moment there is no quality check software that can simultaneously process the data from GPS/BDS/GLONASS/Galileo.According to this,we developed a software that is similar to TEQC,by which the latest version of GNSS data can be processed.The reliability of this program was also verified by the data of iGMAS.At the meanwhile,the quality of iGMAS data was also analysed.The result shows that clock jump appears for some receivers of iGMAS,the multipath periods for BDS GEO is not obvious compared to MEO,what is more,the SNR of BDS is also different from GPS and GLONASS.
Whole exome capture in solution with 3 Gbp of data
We have developed a solution-based method for targeted DNA capture-sequencing that is directed to the complete human exome. Using this approach allows the discovery of greater than 95% of all expected heterozygous singe base variants, requires as little as 3 Gbp of raw sequence data and constitutes an effective tool for identifying rare coding alleles in large scale genomic studies.