Central to the USIGS architecture is a robust data environment that facilitates the creation and management of accurate, precise, detailed, and timely data. The USIGS Conceptual Data Model (UCDM) consists of a set of data models, standardization procedures established by DoD, NIMA and the IGC, and the interfaces necessary to integrate the Conceptual Data Model with other architecture components. Through this structure, data is standardized horizontally at various levels throughout the enterprise, while maintaining vertical traceability.

Figure 5-1 Data Model Interrelationships Within the USIGS Architecture

Figure 5-1 depicts the hierarchy of data models within USIGS, and the three tiers at which they are related. The construction, alignment and maintenance of the different model types is an iterative process that reflects changes in the operational mission and scope. The USIGS Conceptual Data Model (UCDM) provides a semantically rigorous, functionally neutral, normalized definition of the data needed to satisfy the combined information requirements for the community. The model's entities and attributes are consistent with the standardized data contained in the DoD Data Dictionary System (DDDS). In addition, they are controlled and cited in the Technical Architecture. Development of the conceptual model is correlated with the USIGS Information Exchange Requirements Matrix (IERM), as well as the operational vision that defines the business rules and strategies that govern the enterprise.

Existing NIMA configuration control processes and the NIMA Configuration Control Board (NCCB) are the mechanisms to control and manage the UCDM, the Logical Data Models (LDMs) and the Physical Data Model (Internal Schema), and to keep them synchronized. The UCDM is maintained by NIMA/AR. LDMs and Physical Data Models (Internal Schema) are developed and maintained by program offices. LDMs extend the UCDM to the level of detail needed for specific functions and performance characteristics. LDMs must conform fully to the UCDM. The LDM is the basis for the Physical Data Model for specific applications.

Developers initially examine the UCDM and the associated data dictionary to determine whether UCDM data elements satisfy their requirements. If the UCDM does not contain all the required entities and attributes, the developer uses the applicable parts of the UCDM and proposes an extension to the UCDM via a Request for Change for those data elements which are publicly visible. For entities and attributes which are not yet publicly visible (i.e., used only by the specific application), the data requirements are documented in the LDM and the LDM is placed under NCCB control, but the UCDM is not extended. Developers of LDMs collaborate with NIMA/AR during LDM development to ensure conformity of LDMs to the UCDM.

From a user's perspective, the USIGS Conceptual Data Model supports the concepts of seamless information discovery and access across the enterprise, and provides for a virtual information service, thus increasing interoperability among data holdings. Data access should allow transactions across a spectrum of resources without the user's awareness; there should be no need to perform parsing, patching or joining at seams caused by either production handling, data content or storage limitations.

The USIGS Conceptual Data Model enhances production and exploitation processes by supporting co-production, facilitating value-added-updates, maximizing the ability to share data, and minimizing errors in data re-use. Data will meet certain conditions, particularly, uniqueness, consistency, integrity, error detection and correcting at both logical and semantic levels, to ensure that the right data is applied to the right activity. From a data management perspective, the maintenance of data in this environment is far more efficient, and cost effective than in a less structured schema. For example, the Conceptual Data Model provides the ability to analyze data across the enterprise. As a result, redundant data can be identified and, wherever appropriate, eliminated.

For the development community, a structured data environment reduces the cost, complexity, and overall level of resources expended on the development of software and computer system data components. This structure is necessary for the efficient exchange of data either as an exchange format or as information requirements of an application program interface (API) specification. Data models can guide development of systems that are capable of sharing data at the most elemental level, including access of the same physical store. This architecture encourages the definition of common operational 'concepts' over areas of shared data, migration of legacy and other data to a shared environment, while minimizing operations impact. A robust data environment must also promote rapid integration of emerging technology and standards. Standards, both national and international, will be incorporated to exploit the competitive development of off-the-shelf solutions.

In summary, data is common to all components of USIGS. The ever-increasing quantities of a multitude of data types pose significant obstacles for users, managers and developers. By adopting a Conceptual Data Model which combines an integrated data model implementation, a solid data standardization strategy, and architecture-wide integration of data elements, USIGS will have the structure and flexibility necessary to meet the challenges that lie ahead.

The C4ISR Framework describes a core set of architecture products and functionality, as a minimal set of rules concerning the arrangement, interaction, and interdependence of the parts or elements of a C4ISR system. Implied in these rules is a data environment which, from a data perspective, ties together the Operational, Technical, and Systems Architecture through a common information infrastructure. This set of rules serves to ensure that a conforming system will successfully satisfy its specified operational requirements. The USIGS Conceptual Data Model reflects:

The USIGS Conceptual Data Model (UCDM) describes the common information used by the business elements of USIGS. It contains three components: a fully attributed entity relationship diagram, a data dictionary, and a representation of business rules and relationships between data.

The entity relationship diagram and business rules are represented in standard IDEF1X graphic format (see Figure 5-2, 1^st view). The data dictionary defines and describes in detail all elements reflected in the graphics . The information is organized by entity, attribute, and acceptable domain value (see Figure 5-2, 2^nd view). Although the data model published reports are represented as graphic and dictionary excerpts, the two are integrated in the master database, and managed using the ERWIN modeling tool.

"The USIGS Conceptual Data Model is compliant with FIPS Publication 183, Integrated Definition for Information Modeling (IDEF1X )and DoD Manual 8320.1-M-1, Data Standardization Procedures as mandated by DOD Directive 8320.1, Data Administration. DISA provides a repository for the centralized management of the DoD data standards and related information. The Defense Data Dictionary System (DDDS) is the primary tool to support the DoD Data Administration Program in developing and managing standard data in accordance with Directive 8320.1. It provides a mechanism for defining metadata; cross-referencing and consistency checking; and supports the standardization of data element names, definitions, and relationships. The Personal Computer Access Tool (PCAT) is a PC version of the DDDS. The PCAT is easy to use and allows users the flexibility to design their own queries against the DDDS holdings. The USIGS Data Model and the definitions and associated metadata for the data elements derived from the model comply with the requirements of DoD 8320.1-M-1. Many of the data elements in the USIGS DM are in the DDDS either as approved DoD Data Standards or in developmental status. Extensions to the UCDM will continue to be consistent with 8320.1-M-1 and DDDS requirements. However, the focus of the Conceptual Data Model team is on expanding the model to meet USIGS requirements. As time and resources permit, additional data elements derived from the UCDM will be submitted to the DDDS and the DoD approval process.

The DDDS supports only unclassified processing. To provide repository services for classified or sensitive data elements, ASD/C3I developed the Secure Intelligence Data Repository (SIDR). The SIDR will include the unclassified data models and data elements from the DDDS and will add models and elements which are classified.

The USIGS Conceptual Data Model consists of appropriate extracts of both DDDS and SIDR necessary for coordination with the communities beyond the USIGS. Since the entire data requirements of NIMA and USIGS will go beyond the geospatial, imagery, and imagery intelligence domains, other data models and definitions are referenced beyond those that are NIMA responsibility.

The UCDM is described in a the USIGS Conceptual Data Model Report, as illustrated in Table 5-1.

Table 5-1 USIGS Conceptual Data Model Report Contents

Figure 5-3 USIGS Conceptual Data Model Product Linkages

A: The UOAD identifies the operational elements and information needs to the UCDM.

B: The technical architecture defines the standards for data modeling and data standardization.

C: The UCDM defines the combined information requirements for the community. LDMs must conform fully to the UCDM. LDMs may feed back new data requirements to the UCDM.

D: The UCDM defines the data elements for system architecture data stores.