The preliminary design review for the new Data Transmission System (DTS) for the ALMA Telescope has been completed successfully, allowing the development project to proceed to the next phase of detailed design. This system is being developed as part of the Wideband Sensitivity Upgrade (WSU), which aims to significantly enhance ALMA’s observational capabilities. The WSU encompasses performance improvements for many components including receivers. The DTS plays a critical role in transferring the vast amounts of data generated by astronomical observations to the correlator and spectrometer at high speeds.

The development is led by the NAOJ in collaboration with the National Radio Astronomy Observatory (NRAO) in the United States. Additionally, Photonic Network Laboratory of the National Institute of Information and Communications Technology (NICT) in Japan has been providing technical support. The team aims to meet the requirement of a data rate of 1.2 Tb/s, approximately 10 times higher than the current maximum rate of 120 Gb/s. The team also has set a stretch goal of supporting a data rate of 1.6 Tb/s.

The preliminary design review is a crucial process to evaluate the technical feasibility and progress of the development. A review meeting, attended by reviewers, stakeholders, and members of the development team, was held on October 24, 2024, at the Mitaka Campus of NAOJ. During the meeting, the development team provided detailed reports on the system design, performance verification test results, and other key aspects. The participants engaged in active discussions, offering constructive feedback on the technical matters. Furthermore, at the NAOJ Advanced Technology Center on the same campus, a demonstration using the DTS components was presented. This provided stakeholders with a valuable opportunity to see and observe the WSU equipment in actual operation for the first time.

The review panel acknowledged the development team’s efforts in overcoming challenges during the design process to meet the demanding technical requirements. Having passed this important milestone, the team has now proceeded to the critical design phase, aiming to bring the WSU system closer to realization.

A group photo of the in-person participants of the review meeting, taken in front of Japan’s first millimeter-wave radio telescope (constructed in 1970) preserved at the Mitaka Campus of the NAOJ. The fifth person from the right is Dr. Shun Ishii, the project manager for the Data Transmission System development. (Credit: NAOJ)

Scenes from the demonstration at the Advanced Technology Center. Dr. Takeshi Kamazaki from NAOJ (left photo) and Christoph Jacques from NRAO (right photo) provided explanations to the participants during the demonstration. (Credit: NAOJ)

Core Members of the Development Team
Shun Ishii (NAOJ), Takeshi Kamazaki (NAOJ), Christoph Jacques (NRAO), Eiichi Ebihara (NAOJ), Miho Fujieda (NICT)

Related Link
Upgrade of ALMA Data Transmission System Led by Japan Starts