Microwave Lunar Focus Group Meeting: AWS Geometry 2026-09-30

Attendees

Niutao Liu (Fudan U.) – Chair

Martin Burgdorf (U. Hamburg)

Tim Hewison (EUMETSAT)

Dezhang Li (Fudan U.)

Summary

The meeting focused on Niutao’s presentation of his research on AWS Lunar Observations and pointing beam performance assessment, which is currently under review for IEEE TGRS.

Niutao detailed his method for calculating pointing directions, along-track and cross-track FWHM, addressing antenna temperature differences between nearby frequency channels, and inter-channel performance assessment across different frequency bands. His presented findings showing consistent results across channels with some variation between different observation periods, and validated his FWHM measurements using antenna temperature simulations.

The analysis revealed an increasing trend in antenna temperature with frequency for lunar observations, particularly for AWS-1 and AWS-3 data, which Niutao attributed to small inter-channel FWHM differences caused by frequency variations. He presented detailed work on analyzing lunar observations to invert antenna beam widths (FWHM) and normalize antenna temperatures across different AWS channels. The analysis revealed differences in FWHM between channels, with AWS-4 showing the smallest differences and most consistent results.

Tim and Martin provided feedback on the work, discussing the importance of validating the results against the ATBD documentation and considering factors like sun-moon distance and beam rotation effects during space views.

The team also discussed plans for the upcoming Lunar Calibration Workshop in November.

Presentation

AWS Lunar Observations and Pointing, Beam, and Inter Channel Performance Assessment – Niutao Liu (Fudan U.)