A team of researchers from the Xi'an Institute of Optics and Precision Mechanics (XIOPM) of the Chinese Academy of Sciences developed a Doppler heterodyne Wind Imager (DWI), marking China's first vector wind field detection payload for the middle and upper atmosphere. The DWI was launched aboard the "Tianlu-1" satellite and has already acquired its first in-orbit interferograms.

In application practice, the near-space atmospheric wind field significantly affects spacecraft launch and return, the design and application of hypersonic vehicles, as well as the operational support for radio communication and satellite navigation. In terms of scientific research, wind field data in the region are of great help in understanding major scientific issues such as weather and climate change, energy balance in the Sun-Earth system, which are of great interest in current geoscientific research.

The atmospheric wind field is a crucial parameter for understanding the dynamics of the middle and upper atmosphere, directly influencing the transportation of atmospheric matter and energy as well as structural evolution.

In practical applications, the near-space atmospheric wind field significantly impacts spacecraft launches and returns, the design and operation of hypersonic vehicles, and provides operational support for radio communication and satellite navigation. Additionally, wind field data are essential for addressing major scientific issues such as weather patterns, climate change, and energy balance in the Sun-Earth system, all of which are of great interest in contemporary geoscientific research.

On January 17, 2025, at 12:07 PM, the remote sensing satellite "Tianlu-1" was successfully launched and entered its designated orbit. The DWI, one of three payloads aboard "Tianlu-1," is notable for being the world's first Doppler asymmetric spatial heterodyne interferometric system equipped with a dual-field-of-view coupled interferometer.

Utilizing a limb viewing mode, the DWI detects the atmospheric oxygen atom airglow spectral line (557.7 nm green line), enabling it to obtain continuous profile information of the horizontal wind field within an altitude range of 80-150 km. The innovative three-time imaging scheme employed by the payload effectively reduces its volume and weight while allowing for simultaneous calibration of divided fields of view, thereby enhancing the accuracy of wind field detection.

Recently, the DWI has conducted in-orbit testing and observation missions. The initial batch of acquired interferogram data includes Level 0 (L0) raw interferogram data and Level 1 (L1) preprocessed interferogram data. Key indicators such as signal-to-noise ratio, modulation degree, and residual distortion have all met expectations, confirming the stability and reliability of the DWI payload during its in-orbit operations.

The successful in-orbit application of the DWI payload will provide essential data for research in areas such as the dynamics of the middle and upper atmosphere, thermosphere-ionosphere coupling, and atmospheric numerical simulation. Furthermore, it will support the design and operation of near-space vehicles, space radio communication and navigation, as well as spacecraft launch and return operations.

Fig1. DWI body part. (Image by XIOPM)

Fig2. DWI in-orbit interferograms with dual-field-of-view coupling and simultaneous calibration. (Image by XIOPM)