WSU Program

Status

The WSU is now well underway with key subsystems under development, including new receivers, digitizers, data transmission system, and correlator. In parallel, the observatory is advancing the detailed planning towards implementation through a careful project management and systems engineering approach based on an integrated Conceptual System Design, which outlines the upgrade's hardware, computing, and science operations aspects. The substantial gains in the observing efficiency enabled by the WSU will further enhance ALMA as the world-leading facility for millimeter/submillimeter astronomy.

Next Steps

Efforts in Q1 and Q2 2024 have focused on preparing a Conceptual System Design Description (CoSDD), the Initial Program Plan, and the update of System Technical Requirements (STR) and different ALMA standards. The next detailed steps at system level in the planning are as follows:

  • Assembly, Integration, Verification, and Commissioning (AIVC): The current deployment concept will evolve into a more detailed AIVC plan, clarifying the scope of work, organization, timelines, and resources. This plan will cover the initial planning, AIV of the first hardware components on site, retrofitting plans for the signal chain in the 66 ALMA antennas, and the commissioning of arrays of increasing numbers of antennas.
  • Transition to WSU operations: once the AIVC phase is completed, the WSU system will be available for scientific observations. In the coming months, a plan to transition from the current operations model to an operations model suitable for the WSU will be developed.
  • Computing and Science Operations: The upgrade of these subsystems to support the WSU will be better defined, and detailed implementation plans, as well as the organization and resources needed, will be established. Initial development work to prepare the software and computing infrastructure necessary to support AIVC will start.

Timeline

In terms of the detailed timeline of the planning phase, the program definition moved towards the delta-SRR (System Requirement Review) / Initial Project Plan Review in July 2024 and the Preliminary Design Reviews (PDR) of most of the WSU Signal Chain development projects that are being held between June and November 2024. At that time, the design will move into a more mature planning phase in which the Conceptual System Design will evolve into a System Design through the down-selection of design alternatives at the system level, increasing the definition of design choices, and adding additional information on the commissioning of the new system and the transition to operations. The Initial Program Plan will also evolve towards a Program Plan including costs and effort estimates, with a detailed timeline after defining the Work Breakdown Structure of the different WSU deliverables. The main milestone of that phase at the system level will be the System / Program Plan Review, planned for March 2025. In this phase, the Development Projects will hold Critical Design Reviews (CDR), when designs will be fixed and detailed implementation plans reviewed. Once this phase is complete, the WSU will have mature designs for the different subsystems, a system-level design, and a reviewed program plan. At that stage, all will be ready for the program's execution through different projects.

Lifecycle of the WSU Program from Initiation to Closure. Closure of the program will be achieved through the closure of individual projects. NOTE: Bands 6 and 8 receiver upgrades have been approved to develop prototypes or first units. It is expected that those proposals will be followed up by full construction proposals to deliver receivers for all ALMA 66 antennas plus spares.