Prediction of group delay distribution around receiving point using modified IRI model and IGRF model

The international reference ionosphere (IRI) model is generally accepted standard ionosphere model. It describes the ionosphere environment in quiet state and predicts the ionosphere parameters within a certain precision. In this paper, we have made a breakthrough in the application of the IRI model by modifying the model for regions of China. The main objectives of this modification are to construct the ionosphere parameters foF2 and M (3000) F2 by using the Chinese reference ionosphere (CRI) coefficients, appropriately increase hmE and hmF2 height, reduce the thickness of F layer, validate the parameter by the measured values, and solve the electron concentration distribution with quasi-parabolic segment (QPS). In this paper, 3D ray tracing algorithm is constructed based on the modified IRI model and international geomagnetic reference field (IGRF) model. In short-wave propagation, it can be used to predict the electromagnetic parameters of the receiving point, such as the receiving area, maximum useable frequency (MUF) and the distribution of the group delay etc., which can help to determine the suitability of the communication. As an example, we estimate the group delay distributions around Changchun in the detection from Qingdao to Changchun using the modified IRI model and IGRF model, and provide technical support for the short-wave communication between the two cities.