polynomial model, grey model, and Auto-Regressive Integrated Moving Average (ARIMA) model are evaluated with GNSS precise satellite clock products provided by GFZ.
In this article, three common-used prediction models e.g. In general, the performance of existing prediction models varies with different types of satellite clocks, lengths of fitting arcs and predicting arcs. However, due to the different types and quality of the space-borne atomic clocks, it is rather difficult to predict high-accuracy satellite clock errors by using one unique prediction model. Satellite clock error prediction plays a key role in GNSS technology for Positioning, Navigation and Timing (PNT) service.
The kinematic example using three IGS stations shows that the kinematic RTPPP precision based on the proposed clock model has improved about 30, 72 and 44 % in the east, north and height components. The numerical examples using the data set of 140 IGS stations show that the static RTPPP precision based on the proposed clock model has been improved about 22.8 and 41.5 % in the east and height components compared to the IGU-P clock products, while the precisions in the north components are the equal. In addition, the RTPPP method was chosen to test the efficiency of the new model for real-time static and kinematic positioning. The simulation results have shown that the proposed prediction model can give a better performance than the IGU-P clock products and can achieve precision better than 0.55 ns (16.5 cm) in real-time predictions. Second, initial deviations of the predictions are reduced by using a recomputed constant term. First, the proposed prediction model adds a few cyclic terms to absorb the periodic effects, and a time adaptive function is used to adjust the weight of the observation in the prediction model. An improved prediction model for satellite clocks is proposed in order to enhance the precision of predicted clock offsets. However, the satellite clock offsets of the IGU-P products have not shown sufficient high-quality prediction to achieve sub-decimeter precision in real-time precise point positioning (RTPPP), being at the level of 1–3 ns (30–90 cm) RMS in recent years. Lead (Pb)-Free and Green information can be found on individual datasheets or Pb-Free & Green Page.The GPS orbit precision of the IGS ultra-rapid predicted (IGU-P) products has been remarkably improved since 2007. Where can I find the information on your Pb-free and "Green" packaging? Where can I find Mean Time Before Failure (MTBF) or Failures In Time (FIT) values for Pericom products?įIT and MTBF data can be found at Pericom's Quality webpage.
Lead-free products are marked and ordered with the letter "E" suffix at the end of the part number. For lead-free products, they are composed of 100% matte Sn. What is the lead finish for Pericom products? What about lead-free?Īll Pericom's products that are not lead-free are composed of 85% Sn and 15% Pb.
Please refer to datasheet s for detail ed application. What is the 3-wire interface?ģ-wire interface is the same as SPI with Data, CLK and CS signals to support high frequency clock without the need of pull-up resistor s. Also, it can speed up end-product mass production schedule, and also enhance clock accuracy and RTC consistency. The benefits are PCBA footprint saving and shortened test process and design lead time. What are the benefits for RTC module to integrate crystal? However, we recommended that you contact your regional sales office. Not all obsolete parts will have a direct replacement. Real Time Clock (RTC) FAQs Is there a replacement for an obsolete part?
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