低轨星座对静止轨道卫星同频干扰指标研究

随着全球低轨星座系统的快速部署及应用，非静止轨道卫星对静止轨道卫星系统的同频干扰问题日益凸显。为保护静止轨道卫星系统不受有害干扰，国际电联现行无线电规则中规定了非静止轨道卫星系统应满足的等效功率通量密度限值或干扰噪声比限值，但所适用频段及限值标准仍在不断修订完善中。为了精确定量评估低轨星座对静止轨道卫星的同频干扰，通过对等效功率通量密度限值和干扰噪声比限值的确定方法及演进历程进行研究，分析了上述限值与静止轨道卫星实际被干扰的对应关系，并以典型倾斜轨道星座和极地轨道星座为例，分析了不同干扰指标对卫星系统间干扰判定结果的影响，当静止轨道卫星系统的实际被干扰门限低于国际电联制定等效功率通量密度限值选用的参考门限时，建议低轨星座选择干扰噪声比限值作为开展频率干扰分析与判定的依据。

Research on co-frequency interference criteria of low orbit satellite constellations to geostationary satellites

With the rapid deployment and application of low orbit satellite constellations around the world, there is an increasing risk of co-frequency interference of low orbit satellite constellations to geostationary satellite systems. To protect geostationary satellite systems, the current ITU Radio Regulations set equivalent power flux density limits or interference-to-noise ratio limits for non-geostationary satellite constellations, but the applicable frequency bands and limit standards are still being continuously improved. In order to accurately and quantitatively evaluate the co-frequency interference of low orbit satellite constellations, the methods and evolution of the equivalent power flux density limits and interference-to-noise ratio limits are investigated in this work. The analysis of the relationship between the mentioned limits and the practical interference of geostationary satellite systems is presented. Taking a typical inclined orbit constellation and a polar orbit constellation as examples, the effect of different criteria on the determination of interference of low orbit satellite constellations to geostationary satellite systems is analyzed. When the practical interference threshold of a geostationary satellite system is lower than the reference threshold chosen by the ITU in setting the equivalent power flux density limits, it is recommended that low orbit satellite constellations choose the interference to noise ratio limits as the basis for carrying out frequency interference analysis and determination.