ABSTRACT. The equipment needed to establish a readout receiving 

 station for the Data Collection System (DCS) is discussed in 

 general terms. The parameters and characteristics of the DCS 

 are described as they affect ground station equipment design. 



I. INTRODUCTION 



The SMS/ GOES ' family of meteorological satellites provides, along 

 with other capabilities, a DCS to relay in situ environmental data 

 obtained from a variety o^ sensors located in remote areas. 

 Typical sensors measure hydrologic, oceanographic, meteorological, 

 rnd other types of environmental parameters. 



The National Environmental Satellite Service (NESS) provides 

 ground facilities to receive the data transmitted to the satellite 

 from the user's ground-based sensors and makes these available to 

 users at the World Weather Building, Camp Springs, Maryland. DCS 

 users must supply the ground communication link between their own 

 facilities and Camp Springs. 



Under some circumstances, users may wish to provide their own 

 satellite ground receiving station facilities. 



The equipment needed to receive DCS data directly from the 

 satellite is both sophisticated and expensive; ordinarily this 

 expense cannot be justified except where the communications links 

 between the user and Camp Springs, Maryland, are long and expensive 

 or where the time required to establish these links can compromise 

 the usefulness of the data. Another consideration is that some 

 emergency situations, e.g., floods, that the platforms are designed 

 to monitor may destroy land line communication circuits from NESS 

 to the user's processing facility. Further complicating the 

 picture is the fact that a number of design tradeoffs are possible, 

 so that there is no single optimum choice of equipment. 



This report lists some of the parameters of the DCS system and 

 describes the manner in which they affect the components 

 of a satellite receiving system. It is assumed that the reader 

 has a basic knowledge of physics and some experience with satellite 

 receiving systems. 



For the purpose of this discussion, the description of the DCS will 

 will be divided into six parts. The first of these, Part II, is 

 a brief description of a typical station for receiving satellite 

 data. Part III discusses the signal level available on the Earth's 



^SMS stands for Synchronous Meteorological Satellite; GOES stands 

 for Geostationary Operational Environmental Satellite. The SMS 

 satellites are prototypes for the GOES satellites. 



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