TY - JOUR T1 - Iranian Permanent GPS Network Receivers Differential Code Biases Determination using Single Difference Observation Geometry Changes TT - تعیین مقادیر اریب تفاضلی کد گیرنده‌های شبکه دائم GPS ایران با استفاده از تغییرات هندسه مشاهدات تفاضلی یگانه JF - kntu-jgit JO - kntu-jgit VL - 6 IS - 1 UR - http://jgit.kntu.ac.ir/article-1-562-en.html Y1 - 2018 SP - 45 EP - 56 KW - Differential Code Bias KW - Single Difference Observation KW - Total Electron Content N2 - Differential Code Bias (DCB) of GPS satellites and receivers are one of the most important error sources in a positioning and ionosphere modeling using GPS code observations. International GNSS Services (IGS) compute and publishes the DCBs of GNSS satellites and its nework GNSS receivers as an ionosphere single layer model byproduct. Determination of Iranian Permanent GPS Network (IPGN) receivers DCBs independent of ionosphere single layer modeling is the aim of this paper. This method uses single difference observation geometry changes. Total electron content (TEC) differences of single difference observations can be considered as a linear function of its observation differences. When the distance between to receivers and satellite are equal, the effect of TEC will be removed from single difference observation and just the effect of different DCBs of two receivers will be remained in a single difference observation. The proposed method is implemented on a network which includes some IGS GNSS stations and derived DCBs are compared with IGS published DCBs for those stations. The maximum difference is 0.6 nanosecond and the RMSE of the differences is 0.4 nanosecond. This comparision shows the high efficiency of proposed method for determination of GPS receivers DCBs. Then IPGN GPS receivers DCBs are computed which can be published as a product for users. M3 10.29252/jgit.6.1.45 ER -