We propose a laser occultation method for simultaneous profiling atmospheric temperature and pressure. Measurements can be performed on the optical link between two low-orbit satellites, where frequency-stepwise laser pulses are transmitted from one to the other. These pulses, covering several oxygen absorption lines in the wavelength domain, measure the broadened atmospheric absorption optical depth along the transmission path with a spectral resolution of tens of megahertz. In this way, atmospheric temperature and pressure are obtained by analysing the retrieved shape and intensity of the spectral lines. With the motion of the two satellites, the inter-satellite optical link penetrates different atmospheric layers at various altitudes, enabling the measurement of the vertical structure of atmospheric thermodynamic parameters from the troposphere to the lower thermosphere. This paper presents an end-to-end simulation of the proposed method, including models for laser occultation beam tracing, radiative transfer, and data inversion. The simulation results reveal that with minimal satellite payload resources, this method can accurately measure temperature and pressure at a vertical resolution of 100 m from 5 km to 90 km altitude with accuracies of ±1.5 K and 5 %, respectively. As the proposed differential absorption laser occultation method is independent of the hydrostatic equilibrium hypothesis for data inversion, it can eliminate errors associated with prior data at reference altitudes. It is believed that our method has provided a promising approach to laser satellite constellation for atmospheric observation.

中文翻译：

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一种星间激光掩星方法，可描绘从对流层到低层中间层的大气温度和压力


我们提出了一种激光掩星方法来同时分析大气温度和压力。可以在两颗低轨道卫星之间的光学链路上进行测量，其中频率步进激光脉冲从一颗卫星传输到另一颗卫星。这些脉冲覆盖了波长域中的几条氧吸收线，以数十兆赫的光谱分辨率测量沿传输路径的拓宽的大气吸收光学深度。这样，通过分析检索到的谱线的形状和强度，就可以得到大气的温度和压力。随着两颗卫星的运动，星间光链路穿透不同高度的不同大气层，实现从对流层到低热层的大气热力学参数垂直结构的测量。本文提出了所提出方法的端到端仿真，包括激光掩星光束追踪、辐射传输和数据反演的模型。仿真结果表明，该方法可以在最小的卫星有效载荷资源下，在5 km至90 km高度范围内以100 m垂直分辨率精确测量温度和压力，精度分别为±1.5 K和5 %。由于所提出的差分吸收激光掩星方法独立于数据反演的流体静力平衡假设，因此它可以消除与参考高度处的先前数据相关的误差。据信，我们的方法为激光卫星星座大气观测提供了一种有前景的方法。