ALMA Wideband Sensitivity Upgrade (WSU)
Based on the development principles of the ALMA development roadmap and the recommendations of the ALMA Science Advisory Committee (ASAC) described in the ALMA 2030 report, the highest priority for development of ALMA this decade should be a transformative increase of the instantaneous processed bandwidth.
With the objective of increasing the system bandwidth by a factor of 2 at least (and a goal of a factor 4), the ALMA Wideband Sensitivity Upgrade (WSU) is a partnership-wide initiative that will realize the recommended development through a series of major hardware upgrades of the array's components. The WSU also seeks to improve the sensitivity of most receivers, as well as the digital efficiency throughout the signal chain. To achieve these goals, the WSU will replace the entire analog and digital signal chain from the output of the receivers through the digital correlator, will replace or upgrade attendant software systems and physical infrastructure, and, on a phased basis, replace existing receivers with upgraded wide bandwidth versions.
We hope to complete the signal chain upgrade by the end of the decade, though some receiver bands will be upgraded later.
This page summarizes resources and information on the principles guiding the WSU project, its scientific promise and its current status.
- ALMA Memo 621 (arXiv:2211.00195), October 2022
- AAS special session, January 2023
- WSU presentation at NRAO Imaging workshop, June 2023
- WSU press release, February 2023: approval of the development of a second-generation correlator and digital transmission system (DTS).
- WSU press release, November 2023: NRAO and NAOJ partner to produce Band 2 and develop upgrade Band 6
- AAS special session, January 2024: ALMA as a high-z powerhouse: the impact of the Wideband Sensitivity Upgrade
