What is the Problem we are Trying to Solve – Radar Next Approach to Requirements

The current NOAA/NWS weather surveillance Doppler radar system has revolutionized the ability of weather forecasters to understand the severe storm environment and issue timely and accurate warnings During the past quarter century, the NEXRAD program has executed a continuous program of modifications, retrofits, technology refreshments, and pre-planned product improvement upgrades with the aim to avoid obsolescence, improve data quality, meet new mission requirements, improve system maintainability and reliability, and control operations and maintenance (O&M) costs. Because of the challenges posed by obsolescence in the current system and the advancement of new technologies, plans are underway to replace the NEXRAD network in the next decade.

The Radar Next team is using a multi-faceted approach to identifying user needs that will inform both observation objective statements and ultimately Radar Next system requirements. Sources of information that will be used to inform this effort include the NOAA Consolidated User Observational Requirements List (COURL), NEXRAD requirements documentation, validated NOAA radar functional requirements, and other historical requirements documents. In addition to this existing documentation the Radar Next team is engaging directly with NEXRAD system users to understand and document their current experience with the NEXRAD system to inform needs (e.g., what to keep, what to change) for its replacement.

The team has convened a Radar Next Working Group (RNWG), composed of representatives of multiple NOAA Line Offices (LO) and external users, to develop a comprehensive and consolidated set of user observational objectives that Radar Next will support. The observation objectives developed through this process are intended to reflect the broad scope of user needs and will provide:

• Top-level user-centric performance requirements for Radar Next
• A basis for the generation of functional requirements and associated documentation for the Radar Next network
• Foundation for ongoing evaluations of the role of NOAA/NWS radar and radar network capability improvements to satisfy user needs and meet strategic performance goals
• Full scope of validated, technically realizable, Doppler weather radar network user needs without regard to budget

The authors will discuss the current state of Radar Next requirements process. They will describe the process being used to collect user needs, parse the needs into mission service areas, evaluate threshold and objective levels of performance, and write observation objective statements. The authors will also discuss how these objectives will be used to evaluate various implementation alternatives and set the stage for the development of the future radar network, associated radar products, and operational concepts.