Chinese scientists develop Doppler Heterodyne Wind Imager that acquires first in-orbit interferograms

DWI body part. (Image by XIOPM)

​Researchers at the Xi'an Institute of Optics and Precision Mechanics (XIOPM) of the Chinese Academy of Sciences have developed the Doppler heterodyne Wind Imager (DWI), China's inaugural payload for detecting vector wind fields in the middle and upper atmosphere. Launched aboard the "Tianlu-1" satellite, the DWI has successfully captured its initial in-orbit interferograms.

The near-space atmospheric wind field plays a pivotal role in various applications, including spacecraft launches and returns, the design and operation of hypersonic vehicles, and support for radio communication and satellite navigation. Scientifically, data on wind fields in this region are instrumental in addressing significant topics such as weather and climate change, and understanding the energy balance within the Sun-Earth system. ​

Understanding the atmospheric wind field is essential for comprehending the dynamics of the middle and upper atmosphere, as it directly affects the transport of atmospheric matter and energy, as well as structural evolution.

​The near-space atmospheric wind field plays a crucial role in practical applications, significantly influencing spacecraft launches and returns, the design and operation of hypersonic vehicles, and providing essential support for radio communication and satellite navigation. Moreover, wind field data are vital for addressing key scientific issues such as weather patterns, climate change, and the energy balance within the Sun-Earth system, all of which are of significant interest in contemporary geoscientific research.​

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

The remote sensing satellite "Tianlu-1" was successfully launched into its designated orbit. Among its three payloads, the Doppler heterodyne Wind Imager (DWI) stands out as the world's first Doppler asymmetric spatial heterodyne interferometric system equipped with a dual-field-of-view coupled interferometer.​

Operating in limb viewing mode, the DWI detects the atmospheric oxygen atom airglow spectral line (557.7 nm green line), allowing it to continuously profile the horizontal wind field at altitudes ranging from 80 to 150 km. Its innovative three-time imaging scheme effectively reduces both volume and weight while enabling simultaneous calibration of divided fields of view, thereby enhancing the accuracy of wind field detection.

The Doppler heterodyne Wind Imager (DWI) has recently completed in-orbit testing and observation missions, capturing initial interferogram data, including Level 0 (L0) raw data and Level 1 (L1) preprocessed data. Key performance metrics such as signal-to-noise ratio, modulation degree, and residual distortion have met expectations, confirming the DWI payload's stability and reliability during in-orbit operations. ​

The successful deployment of the DWI payload is expected to provide essential data for research into the dynamics of the middle and upper atmosphere, thermosphere-ionosphere coupling, and atmospheric numerical simulation. Additionally, it will support the design and operation of near-space vehicles, space radio communication and navigation, as well as spacecraft launch and return operations.