The invention discloses a double-layer
ionosphere modeling method fusing low-
orbit satellite data, which comprises the following steps of: preprocessing ground-based GNSS (Global Navigation
Satellite System) data to obtain an STEC expression of a ground-based GNSS; preprocessing the precise
orbit determination data of the low-
orbit satellite to obtain a VTEC expression of the precise
orbit determination data; obtaining an
electron density profile product of the radio
occultation of the low-orbit
satellite, and obtaining VTEC of the radio
occultation through profile integration; using two groups of spherical
harmonic coefficients to express global VTEC distribution, and constructing an observation equation; and determining weights of different types of data by using Helmert variance component
estimation, and finally solving to obtain two groups of spherical
harmonic coefficients to generate an ionized layer grid product. Projection errors caused by vertical layering in a traditional single-layer model are weakened, meanwhile, precise
orbit determination data and radio
occultation data of a low-orbit satellite are combined, the problem that
ionosphere TEC cannot be correctly layered in a double-layer model is solved, data of areas where GNSS tracking stations are sparsely distributed are supplemented, and the reliability of the GNSS tracking stations is improved. Therefore, a global
ionosphere model with higher precision is obtained.