International Network of Global Fiducial Stations Science and Implementation Issues (1991) / Chapter Skim
Currently Skimming:
4. A Proposed Plan
4. A Proposed Plan
Pages 89-105
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 89... ...
Although collocation of observing systems is a highly desirable feature of the network, stations that operate a limited number of systems will also provide useful information. Hence, many of the core stations considered necessary for the success of FLINN can be considered to exist, although for various scientific and operational reasons some of them will have to be upgraded.
|
From page 90... ...
Because of the anticipated quantity of data to be generated and the burden that it would place on a single center, it will probably be necessary to establish regional processing service centers in each region. It will then be necessary to develop data links among these centers, thereby ensuring a truly international and global system.
|
From page 91... ...
By building on existing structures, adding to the existing networks, and adapting the existing infrastructure to the expanded needs associated with the FLINN concept, we can achieve a gradual and flexible implementation and learn along the way what the best strategy should be. The maps of existing global networks shown in the previous chapter, including in particular the rapidly growing GPS network, show clearly that the ingredients for establishing the GPS core network are nearly all in place.
|
From page 92... ...
Using existing and planned CIGNET and DSN stations, supplemented with a handful of stations that might be collocated with DORIS and PRARE sites, would allow us to meet the GPS core network requirements in the very near future. In fact, enough infrastructure is already in place internationally to begin testing GPS core network operations (orbits, Earth orientation, data flow)
|
From page 93... ...
To address all the postglacial rebound issues with a space-geodetic network, we suggest a long-term goal of approximately 100 sites distributed as described below. Of course, many of these sites will also serve other scientific goals, so the number of sites earmarked specifically for postglacial rebound studies would be smaller.
|
From page 94... ...
1 1 1. ~ · Far-field sites to constrain the rate of tilting of continental margins caused by loading from the oceans: 20 sites deployed in 5 networks of 4 sites each at ~ 400-km spacing in geologically stable environments far from regions where ice melted or is melting.
|
From page 95... ...
To monitor rigid relative motions of the major plates, we require a minimum of three global network sites per plate. Taken at face value, this requirement translates into a globally distributed network of approximately 40 sites, which could include the GPS core network discussed above.
|
From page 96... ...
96 o Ul |
From page 97... ...
of a small number of plates of particular geological interest may be warranted. At high latitudes, especially in North America and Europe, this can be done at least in part by taking advantage of sites distributed for postglacial rebound studies.
|
From page 98... ...
The GPS core network is derived from existing CIGNET and DSN sites, with a few additions in locations where interested parties have stated their intention to operate a permanent GPS station (e.g., Tahiti, where the French intend to collocate GPS and DORIS sites)
|
From page 100... ...
involving a global distribution of seismic stations and extensive near-real-time data exchange exercises among 27 participating countries. These tests involve an elaborate network of National Data Centers and three International Data Centers connected by high-bandwidth digital data links.
|
From page 101... ...
It calls for real-time data acquisition from state-of-the-art instruments and therefore presents a challenging communications problem, to be solved initially by using geostationary satellites with multiple downlink points in various regions of the globe. The data collected by such a network will be of immense value to both the solid Earth and space physics scientific communities.
|
From page 102... ...
102 o WE ~ ~° to o to to o We —°w R _ , ~ ~ ' to | ~| D (/ ~ ~ F w .
|
From page 103... ...
103 in OX OX o ° ID CO O co 111 or ID or a)
|
From page 104... ...
In this respect we must recognize that the scientific objectives of the global network will not be achieved through a single national program, even if such a program intrinsically has a global perspective. Nor will these goals be achieved completely under the umbrella of a single disciplinary international association such as the IAG and its affiliated bodies (e.g., IERS)
|
From page 105... ...
Nevertheless, it serves to illustrate an important point, namely that the path to a more effective network of laboratories used to study the Earth is through international participation. It is also the path for fixture growth of the global network of fiducial sites, especially as the scientific community focuses its attention on very demanding and difficult environments, such as the bottom of the oceans.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.