Aiming at the feature of existing methods for phase delay estimation where double-differenced ambiguity network solutions are not applied,a method for phase delay estimation with the constraint of double-differenced ambiguity network solution is proposed.Firstly,integer doub-le-differenced network ambiguities are utilized as real values to update undifferenced float ambigui-ties estimated by precise point positioning(PPP),uncalibrated phase delay(UPD)estimation is then performed by net-adjustment method.Experimental results show that PPP double-differenced ambiguities and double-differenced ambiguities network solutions show good accordance,with wide/narrow lane standard deviation being 0.07 cycle and 0.11 cycle respectively.PPP double-differenced ambiguities with biases greater than 1 cycle mainly appear in the newly-ascending peri-ods of satellites.The constraint alters undifferenced float ambiguity and thus changes stations en-gaged in UPD net-adjustment,causing narrow lane UPD of around 14％of newly-ascending satel-lites to appear differences greater than 0.2 cycle in a short period compared to the non-constraint case.The difference between with/without constraint inter-satellites single-differenced UPD of a whole day satisfies the zero-mean hypothesis at a confidence level greater than 99.9％,indicating an equivalence between the integer double-differenced network ambiguities constrained method and the non-constrained method for the estimation of UPD and related products.The result of the re-search can provide reference to the work about the resolution of undifferenced ambiguities of refer-ential networks and the fusion of PPP and network real-time kinematic(RTK).
Uncalibrated phase delay(UPD)Double-differencePrecise point positioning(PPP)Am-biguity
维普
万方数据
