China
Africa
Explore chapters and articles related to this topic
Satellite Services and Earth Station Equipment
Published in A.F. Inglis, A.C. Luther, Satellite Technology: An Introduction, 1997
As the result of deregulation, space segment service can be purchased as well as leased. A full transponder or a part of a transponder, for example, for an SCPC circuit, can be purchased. Title to the purchased facilities passes to the customer, who has the right to use them full time, subject only to the technical rules of the FCC and the satellite carrier. The satellite carrier continues to operate the satellite bus for a lump-sum payment or an annual fee. The satellite carrier may also provide backup transponders that would be available for use in the event of failure of the primary transponders.
The Space System
Published in Ron Burch, Resilient Space Systems Design: An Introduction, 2019
Satellite operations encompasses all of the ground activities required to operate and maintain a satellite system. In most cases these activities are performed in the SOC, which is the source of satellite commands and the destination for satellite telemetry data. In certain unique systems, the satellite bus and payload are controlled by separate facilities, but this is much less common.
Instrument Control and Onboard Data Handling
Published in Shen-En Qian, Hyperspectral Satellites and System Design, 2020
Figure 10.3 shows the architecture of the PFCU. The PFCU provides control and monitoring of the hyperspectral payload, acting as an agent to the satellite bus, controlling the MMU, command, and telemetry subsystem. It generally performs the following five tasks:
Metro system disruption management and substitute bus service: a systematic review and future directions
Published in Transport Reviews, 2021
Shuyang Zhang, Hong K. Lo, Ka Fai Ng, Guojun Chen
Yang, Jin, Wu, and Jiang (2017) addressed the issue of congestion and developed a compound strategy to integrate passenger flow control and bus-bridging service for a metro line in Shanghai. Specifically, they proposed a two-stage modelling procedure, in which stage 1 determined the stations and time periods for exercising the passenger flow control strategy and stage 2 identified the optimal bus-bridging services. Zhang, Saadat, Zhang, Ayyub, and Huang (2018) proposed a link-weighted network model considering the physical interval lengths between neighbouring metro stations as weights and applied the model to the Shanghai metro network under different failure scenarios. Itani, Aboudina, Diab, Srikukenthiran, and Shalaby (2019) provided a robust analysis of four factors affecting bus bridging policies: (1) initial dispatch direction of shuttle buses, (2) dispatch time (i.e. the response time for requesting shuttle buses), (3) uncertainty in predicting the incident duration, and (4) reduction of metro passengers demand because of disruption. The model was validated and applied to disruption scenarios in Toronto. Moreover, locating the SB depots is ineluctable. Pender, Currie, Delbosc, and Shiwakoti (2014b) described a method for assessing satellite bus reserve locations by optimising the locations in relation to the time, disruption likelihood and commuters affected, and applied it to the metropolitan rail service in Melbourne.