The high density and coverage of the commercial microwave links, especially in populated areas, are very beneficial for high-resolution reconstruction of rain fields. But what about other advantages of implementing such technology for opportunistic rain monitoring? In a recent publication, researchers fromHohaiUniversity in China and TelAviv Universityin Israel shed some light on such advantages.

“Unlike rain gauges which represent the rain in a specific location, the data monitored by commercial microwave links actually incorporate the rainfall information for the entire path of the link, which can be as long as hundreds of meters and even a few kilometers. While the final retrieval results do not reflect the specific spatial variability of the rainalongthe link path, we wanted to knowwhether this hidden information can help us to reconstruct the rainfall field.”says Xin Zheng, a Ph.D. candidate currently studying at Tel Aviv.The researchers created a set of simulations with pre-determined rain profiles, and examined how different mixture of rain gauges and links cope with monitoring these rain profiles. These mixture of monitoring networks have the same number of sensors andthe only difference between them is theproportion of links vs. rain gauges.

“The results of our study showed that as the number of links increases (and so the number of rain gauges used decreases), we can achievemore accurate rainfall estimates, at least in some scenarios. Also, by “splitting” each link and treating it as a set of multiple virtual rain gauges instead of one line of sight also leads to better monitoring results, but this improvement does not seem to be as good as expected.”, explains Xin.

 “Although this study did not take into considerationsome errorswhich can sometimes affect links’ data, it shows that we can get reliable, and sometimes even better, rain field reconstruction results by using path-integrated data. In fact, we basically did not implement any complex pre-processing stages on the raw links data, which could have potentially further improved the outcome. With better models, we can definitely geteven better results, and we as well as our colleagues are currently working on it.”, adds Xin.

Check the publication here:

Zheng, X., Messer, H., Wang, Q., Xu, T., Qin, Y., & Yang, T. (2022). On the potential of commercial microwave link networks for high spatial resolution rainfall monitoring in urban areas.

Atmospheric Research, 106289.
https://doi.org/10.1016/j.atmosres.2022.106289