Development of a 22 GHz ground-based spectrometer for middle atmospheric water vapour monitoring

• Published in: European Journal of Remote Sensing
• Main Authors: Pietro Paolo Bertagnolio, Giovanni Muscari, James Baskaradas
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor & Francis Group 2012
• Subjects: Microwave remote sensing; water vapour; stratosphere; Antarctica; antenna measurements; Oceanography; GC1-1581; Geology; QE1-996.5; Antarc*
• Online Access: https://doaj.org/article/2d0ac339704f406e97bf0114965e3098

The water Vapour Emission SPectrometer for Antarctica at 22 GHz (VESPA-22) has been designed for long-term middle atmospheric climate change monitoring and satellite data validation. It observes the water vapour spectral line at 22.235 GHz using the balanced beam-switching technique. The receiver antenna has been characterized, showing an HPBW of 3.5° and a sidelobe level 40 dB below the main lobe. The receiver front-end has a total gain of 105 dB and a LNA noise temperature of 125 K. A FFT spectrometer (bandwidth 1 GHz, resolution 63 kHz) will be used as back-end, allowing the retrieval of H2O concentration profiles in the 20 to 80 km altitude range. The control I/O interface is based on reconfigurable hardware (USB-CPLD).