Document Type
Thesis
Date of Award
1-31-1989
Degree Name
Master of Science in Electrical Engineering - (M.S.)
Department
Electrical and Computer Engineering
First Advisor
John D. Carpinelli
Second Advisor
Anthony D. Robbi
Third Advisor
Mehmet Toy
Abstract
A three layer methodology is presented for designing spacecraft onboard computer systems. The system design is perceived as a sequence of three hierarchical layers: the Dedicated Processing Layer, the Application and Support Processing Layer, and the Communications Processing Layer. Each layer implements a distinct set of functions and offers services at different levels of abstraction. As opposed to the ISO/OSI Reference Model, where the prime objective is to implement peripheral interaction between two systems, the layered approach used here is to address the problems in system design itself. The problem is approached in a bottom-up fashion, starting with the description and design of the lowest layer (Dedicated Processing Layer), which has few requirements, to the description and design of higher layers (Application & Support Processing Layer and Communications Processing Layer), which have extensive requirements. Basic functions and the related services in each layer are specified to provide the infrastructure. It is shown that each layer can be implemented independently by a distinct set of resources. Also, the identification of these resources in the system becomes more manageable if it is dealt with under the requirements and constraints of each layer.
Implementation aspects of the functions in each layer are discussed in four different types of systems: Centralized System, Hierarchical Distributed System, Functional Distributed System, and Autonomous Decentralized System. Each system is analyzed for its modularity and supporting features for standardization of efforts.
Although the methodology applies to all types of architectures, its best application is seen in distributed computer systems where operational visibility into the system is an inherent problem. In the end a conclusion is given to reemphasize the need to develop the methodology and the goals achieved by it.
Recommended Citation
Ahmad, Mohammad Nadeem, "A methodology for designing spacecraft onboard processing systems" (1989). Theses. 2702.
https://digitalcommons.njit.edu/theses/2702
