RCA-EO defines requirements in terms of what needs to be observed, rather than in technology terms. For example, users may state a requirement for land surface temperature, land surface topography, or vegetation condition with associated attributes such as where and when it’s needed and how accurate it must be. Requirements defined in these terms can be matched against a variety of current or expected spaceborne, aerial, or ground-based Earth observation capabilities. Requirements based on observation needs are typically long-term and can be flexibly re-mapped to new technologies as they evolve and emerge. This technology-agnostic approach is being developed to reduce the burden of redundant requirements collection efforts, which are often difficult to reuse or re-apply.
In the initial stages of the requirements development process, a "value tree" is constructed. In simple terms, a value tree is a hierarchical model that links an organization’s goals and objectives to applicable Earth observation data and systems. Using the value tree information as context, user requirements are developed by identifying what Earth observation is at the core of a program objective. For example, flood extent is largely a function of land surface topography, so a high level requirement for a flood mapping objective would be land topography and its attributes. RCA-EO employs experts trained to collect requirements from subject matter experts in the Federal science and user community.
- Develop, validate, and maintain a database of user requirements collected from USGS and other Federal agencies
- Use requirements and value tree data to prioritize product and service investments
- Use requirements to inform future Landsat and other mission characteristics