The modification of IRI model for Chinese region and its verification

The International Reference Ionosphere model (IRI) 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've made a breakthrough in modifying the IRI model for Chinese region. Construct the ionosphere parameters foF2 and M(3000)F2 by using the CRI (Chinese Reference Ionosphere) coefficients, appropriately increase hmE, hmF2 height, reduce the thickness of F layer, validate the parameter by the measured values, and solve the electron concentration distribution with QPS (quasi-parabolic segments). Then, 3D ray tracing algorithm was constructed based on the modified IRI model and IGRF geomagnetic field model. Finally, the calculated group paths by using the modified IRI model were compared with experimental results to prove accuracy.