Objective  Spaceborne wind interferometer uses the limb observation mode to measure the Doppler shift of atmospheric airglow lines to realize atmospheric wind field detection. The effective coverage of interferometer will be limited by the source and satellite mode. It is of great significance for the application of wind field data to analyze the observation data at the front end of satellite mission planning to determine whether it meets the scientific objectives.

  Methods  According to the satellite orbit parameters and the instrument boresight parameters, the geometric model of limb observation is established (Fig.1), and the distribution of limb tangent points of instruments during satellite operation is simulated. Then, the main factors affecting the effective observation of the instrument are discussed, and the relationship between the solar incidence angle and the effective spatio-temporal coverage of the interferometer at different time periods is analyzed by taking the detection of dayglow as an example (Fig.5). Finally, the method of variable separation is applied to study the influence of satellite orbit parameters on the effective coverage of the wind interferometer, and the coverage percentage of the interferometer under different orbit parameters on the Eurasian is evaluated.

  Results and Discussions  1) The main factors affecting the effective observation of the instrument are the zenith angle and the scattering angle of the sun. The solar incidence angle affects both the latitude coverage and the local time of the tangent point. (Fig.6-8). 2) The coverage efficiency of the instrument is affected by both orbital inclination and orbital altitude. Moreover, orbital inclination is the main orbital parameter affecting the coverage percentage of Eurasia continent. When the orbital inclination is between 60° and 80°, the coverage percentage can reach 100% (Fig.12).

  Conclusions  This paper provides an observational geometric framework for the subsequent design and performance evaluation of the spaceborne interferometer, and realizes the quantitative analysis of the coverage efficiency of payload observation. The model has the ability to be widely used in the analysis of observation models of other types of atmospheric optical remote sensing payloads.