IMINT 102 - Documentation

IDEX II IASS Prototyping

CIIWG Meeting 20 November 1996

1. On 20 November 1996, the Common Imagery Interoperability Working Group (CIIWG) held its seventh meeting at Logicon in Reston, VA. Ronald K. Burns, Information Technology Branch, National Imagery and Mapping Agency (NIMA), chaired the meeting. Vugraphs used at the meeting are referenced and can be found at the appropriate enclosure.

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4. At 0905, John Files, Lockheed Martin Corporation, presented IDEX II IAS Specification Prototyping (Enclosure 4). An IDEX program goal is to migrate to a more open architecture. This migration requires the replacement of custom hardware with commercial equipment and the addition of external interfaces to the image archive to provide access to raw, reformatted, and partially processed image data. A second IDEX program goal is to standardize external interfaces. Lockheed Martin Corporation has been actively supporting the IAS and Common Imagery Interoperability Profile (CIIP) for Imagery Access. Based on the systems developed at the Sunnyvale, Valley Forge, and Gaithersburg facilities, a prototype server implementation test bed and clients are being developed to support interface standardization.

Mr. Files described the 1990 IDEX II architecture and how it has evolved to the current architecture. As performance of commercial equipment has improved, IDEX has migrated away from custom implementations. The wideband network was replaced with the High-Performance Parallel Interface, and hardware compression and expansion has been replaced by software. The IDEX archive has opened up to allow access to image files through an Output Data Server, access to pixel arrays through a Display Broker, and database query and ordering through site-to-site transfer. Current access is through a mixture of custom and standard interfaces. Support of the IAS Specification will mean that standardized interfaces are provided.

The prototype implementation proposed by the IDEX contractor includes the development of a prototype server implementation to Image Access Services Specification (IASS) version 1.1, the use of a CORBA-compliant Object Request Broker (ORB) to implement the Application Program Interface (API), provision of a testbed at the IDEX factory for interface evaluation in April 1997, participation in the interface evaluation, and support of the update of IASS version 1.0 to version 2.0. The goal of the prototype facilities is to use existing technology. In answer to a question concerning potential reuse of the prototype software by other programs, Mr. Files responded that the back end of the API will be specific to IDEX and therefore would not be readily useful to other systems.

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7. At 1103, Norman Spencer, NIMA, presented Digital Production Systems (DPS) Interface Server (DPS-IS) (Enclosure 7). The purpose of his presentation was to provide visibility regarding a NIMA effort that addressses the migration of data delivery services based on 1980's vintage Open Systems Interconnection (OSI) communications software to a CORBA based implementation.

During the 1980s, DPS and IDEX II were developed in parallel. The DPS provides data delivery to MC&G exploitation workstations. The legacy DPS incorporates OSI based custom communication software and custom hardware. Imagery delivery to new systems connected to the DPS is supported by file transfer protocol over a fiber distributed data interface network.

The DPS-IS provides an interface between DPS systems and the new production environment. It provides an interim migration solution for evolution to a standard-based COTS architecture for MC&G systems. DPS-IS allows new clients using transmission control protocol/internet protocol to obtain or store data to the existing DPS. DPS-IS is an ORBIX based implementation, and its image access methods are not based on IAS. The next steps are to complete the initial comparison of image access methods, to identify an approach to integrate DPS-IS and IAS, and to develop an API approach for NIMA library data access services. Mr. Burns commented that there is a need to look at the long term gains versus the cost rather than short term costs alone. He noted that a "wrapper" could be used initially with eventual evolution to the full incorporation of the IAS. He emphasized the objective of creating accepted commercial standards and the need to take advantage of vendor support available through groups such as the OMG.

8. At 1123, Dave Lutz, MITRE Corporation, presented Proposed Changes to the Imagery Access Services Specification (Version 1.0) (Enclosure 8). The new version contains resolution of the profile and notification facility (PNF), elimination of the imagery dissemination facility (IDF), and minor changes to the CAF.

A proposed change to the CAF is to separate the query submission from the results retrieval. This will simplify client interaction because the query submission doesn't have to wait for the query to complete and the client has more control over which and how many results are returned. A question addressed the need to include a "sensitivity level" in the query model. Mr. Lutz responded that, in anticipation of secure ORBs, it was not desirable to mix security into these interfaces since it would have to be removed later. Proposed changes to the IDF include moving functions to PNF and removing the IDF as a separate facility. Changes to the PNF are the new query submission and retrieval methods inherited from the CAF, an added method to allow clients to request notification of new hits against a standing query, and an added method to allow clients to request delivery of new imagery (auto-push). A new client-side interface has been defined to handle incoming notices and imagery pushes. In answer to a question concerning the available levels of auto-push, Mr. Lutz responded that only whole imagery was provided for in the current design, but that other levels, such as chipped imagery, could be considered. Mr. Burns cautioned that it was better to avoid defining interfaces that could become overly complex.

Comments and recommendations from the 19 November 1996 IAS Test Coordination meeting include the need for the IAS and CIIP to include more details, new exceptions, syntax changes, multi-threading issues, ORB limitations, and fault tolerances. The question of when to issue changes was discussed. Mr. Burns noted that version 1.1 will get developers to the 90% level, and he recommended that they not delay development waiting for version 2.0 since this could put them significantly behind in the implementation of the standard. He estimated that version 2.0 could be final by June 1997.