author = "Ambrosio, Ana Maria and Barreto, Joaquim Pedro and Guimar{\~a}es, 
                         Daniele Constant",
          affiliation = "{National Institute for Space Research - INPE} and {National 
                         Institute for Space Research - INPE} and {T\&M Testes de 
                title = "Satellite simulator requirements specification based on 
                         standardized space services",
            booktitle = "Proceedings...",
                 year = "2007",
               editor = "Loureiro, Geilson and Curran, Ricky",
                pages = "171--179",
         organization = "ISPE International Conference on Concurrent Engineering, 14. (CE 
            publisher = "Springer",
              address = "S{\~a}o Jos{\'e} dos Campos",
             keywords = "satellite simulator, requirements analysis, space engineering.",
             abstract = "Operational satellite simulators are used in space missions to 
                         provide validation of Ground Systems and the Operational 
                         Procedures before and after launch of satellite. They may simulate 
                         the satellite, taking into account the space environment and the 
                         ground stations, providing an accurate and realistic modeling of 
                         their interfaces. The simulators must be sufficiently realistic to 
                         allow the operators to run flight procedures as if they were 
                         interfacing to the real satellite. Furthermore, they allow 
                         encountering unknown scenarios that cannot be tested before 
                         launch. The advantages of developing simulators include the 
                         ability to: (i) validate operational procedures, (ii) train 
                         operators before launch and (iii) validate the Satellite Control 
                         System (SCS) and the Telemetry and Telecommand database (Williams, 
                         2004). The high cost and the compression of the development 
                         timescale of a realistic satellite simulator motivated the 
                         definition of a set of functional requirements based on 
                         standardized space services, which is presented in this paper. In 
                         order to improve as much as possible reusability and consequently 
                         decrease cost in development, the use of standards were 
                         intensively adopted specially for the satellite independent 
                         functions, namely, data handling and communication among ground 
                         and on-board systems. Functions related to the on-board data 
                         handling computer and its communication with the ground systems 
                         were based on the ECSS-E-70-41A (2003) standard, which focusing on 
                         telemetry and telecommand packet utilization definition. The 
                         protocol supporting the ground and on-board system communication, 
                         at several layers, were based on the Consultative Committee for 
                         Space Data Systems (CCSDS) recommendations. This paper presents 
                         the results of modeling a set of generic satellite simulator 
                         functional requirements into the UML use case artifact. The 
                         satellite and ground station functions are as much general as 
                         possible, as they were based on practical publications of related 
                         works (Saraf, 2001) and in space service standard (ECSS, 2003). 
                         For a new mission definition, the satellite simulator use cases 
                         model provided a generic basis with which a specific simulator 
                         design could be instantiated. The breakdown and the functions 
                         choices allow its reuse for future micro-satellite and small 
                         satellite programs in different missions. The paper presents the 
                         most common functional requirements of a satellite simulator 
                         described in the use case notation of UML. The breakdown of the 
                         software into modules, the main functions and the advantages of 
                         using use cases to specify this kind of software and the way the 
                         use cases helped the development team in the future satellite 
                         simulators at INPE are also discussed. References: European 
                         Cooperation for Space Standardization (ECSS). ECSS-E-70-41A: Space 
                         engineering: ground systems and operations telemetry and 
                         telecommand packet utilization Netherlands, 2003. Saraf, S.; 
                         Adourian, C.; Melanson, P.; Tafazoli, M. Use of an operations 
                         simulator for small satellites. In: 15th Annual AIAA/USU 
                         Conference on Small Satellite., 2001, Utah, Canad{\'a}. 
                         Dispon{\'{\i}}vel na biblioteca digital URLib: 
                         <http://www.aria.cec.wustl.edu/SSC01/papers/8a-6.pdf>. Acesso em: 
                         17 fev. 2005. Williams, A.; Seymour, M.A. Radarsat-2 Software 
                         simulator: benefits of an early delivery. In: 8th International 
                         Conference on Space Operations, 2004, Montreal, Canad{\'a}. 
                         Proceedings... 1 CD-ROM.",
  conference-location = "S{\~a}o Jos{\'e} dos Campos",
      conference-year = "2007, July 16-20",
           copyholder = "SID/SCD",
                 isbn = "978-184628-975-0",
             language = "en",
         organisation = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 type = "Software Engineering and Simulation",
        urlaccessdate = "19 jan. 2021"