GCDIS/userDIS  Background & Issues
Mark Elkington
GCDIS/userDIS Study
Presentation
	Background and Approach
	Key Characteristics
	ECS as Source of Components
	Current Position
Study Motivation
	NRC:  "Provision of common GCDIS (and UserDIS) software, database structures, and technical 
infrastructure for an interoperable network"

	Study Expectation: There are components of GCDIS/userDIS which ECS could provide 
without leaving its mission envelope and without a lot of additional cost, by carefully 
choosing the appropriate architectural direction.
Boundaries
	Cannot Compromise EOS Primary Mission Objectives
-	Must Preserve EOS Data (An Extremely Valuable National Resource)
-	Cannot Endanger The High-Volume Data Ingest and Production Operation
-	Cannot Degrade Critical Capabilities of EOS Researchers
	ECS Role Must Fit ECS Budget Constraints
	GCDIS/UserDIS Architecture Model Should Identify Components That Are Achievable 
Within The Time Frame Of Current ECS Contract
Approach
Analyze Differences, Formulate New ECS Requirements, Assess Cost
Key Characteristics of 
GCDIS/userDIS
As starting point for architectural analysis, characterized the differences between EOSDIS, 
GCDIS and UserDIS:

User Model Concept
Information Model Concept
System Distribution Concept
System Management Concept
System Capacity Concept
System Quality Concepts
ECS As GCDIS / UserDIS Supplier
	ability to advertise the availability of data and services
	uniform way of referencing data and services in a network
	a broker to resolve the matching of what the user needs with what is offered
	extensible user interface framework - enabling competitive development of components or complete 
service interfaces
	data access services for EOSDIS data with polymorphism characteristics (i.e., allows extension to  
GCDIS/userDIS data sets)
Impact on ECS Components
	separable so that they can be re-used in different configurations
	portable across system and network environments
	support variable capacity
	functions of component can be re-configured outside of ECS environment
	tolerant  of  interface characteristics which differ from those specified for ECS (e.g., 
Reliability, Capacity, Response Time)
Current Position
There are many things which ECS could provide without leaving its mission envelope for 
GCDIS/userDIS, by carefully choosing the appropriate architectural direction