Distributed Arrays of Small Instruments for Solar-Terrestrial Research Report of a Workshop (2006) / Chapter Skim
Currently Skimming:
3 Instruments
3 Instruments
Pages 26-37
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 26... ...
However, significant progress in space physics research requires better geographic distribution of the instruments and enhanced coordination of their data products, which in turn will facilitate focused research and assimilation of the data into advanced computer models. Workshop participants discussed the major ground-based remote sensing instruments, summarizing their capabilities and requirements.
|
From page 27... ...
The measurements permit reliable estimation of plasma density, temperature, drifts, and major ion composition, and with additional physics, it is possible to estimate electric fields and conductivities. Interconnection of the ISRs in real time through high-speed data distribution networks will enable coordinated high-resolution observations of interrelated regions of Earth's atmospheric system.
|
From page 28... ...
It employs nearly identical, largely automated HF radars to observe scattering of plasma irregularities in the E and F regions of the ionosphere. Currently, the network covers most of the northern and southern polar caps, with many of the stations reporting in real time.
|
From page 29... ...
FIGURE 3.2 Artist's concept of the portable Advanced Modular Incoherent Scatter Radar deployed at a highlatitude site to study the response of the upper atmosphere to auroral activity. SOURCE: Courtesy of J
|
From page 30... ...
. For DASI deployment, spaced arrays designed to provide overlapping coverage can be established to monitor the occurrence of strong irregularities due to enhancements of the electric field over wide areas, and thereby provide an inexpensive global electric field monitor.
|
From page 31... ...
Distributed Arrays of Low-Frequency Antennas The pace of advancements in computational power and network capacity will soon usher in a new era for radio astronomy in the form of next-generation, low-frequency, digital aperture synthesis radio interferometers. In a digital array, the signals from each antenna are digitized and sent to a central 31
|
From page 32... ...
By using tomographic restoration techniques, it will be possible to construct a precise three-dimensional view of ionospheric electron content on spatial scales and time scales far beyond anything currently available. Study of the plasma structure and variation on many size scales from tens of meters to hundreds of kilometers can advance understanding of the ionospheric response to solar-terrestrial disturbances and space weather events and will provide important input to ionospheric modeling.
|
From page 33... ...
FIGURE 3.5 Installation of a prototype low-power magnetometer at the South Pole. The system is being designed to operate unattended for up to 3 years on the Antarctic plateau.
|
From page 34... ...
Figure 3.6 shows the complement of passive optical instruments deployed at a research site near Stockholm, Sweden. Active Optical Instruments It is also possible to probe the upper atmosphere with optical radars, called lidars.
|
From page 35... ...
Workshop participants noted two particular advantages that would be derived from deploying arrays of ground-based instruments across Earth: · Spatial distributionIn certain types of observations, the terrestrial location of the detection encodes information. For such observations, a widely distributed array of detectors is necessary to provide a broad field of view or to provide a wide range of energy sensitivity.
|
From page 36... ...
FIGURE 3.7 Data assimilation: a snapshot reconstruction of ionospheric total electron content for the geomagnetic storm in November 2003 shows (top) the output from a physics-based ionosphere forecast model with no data assimilation, (bottom)
|
From page 37... ...
Distributed arrays dramatically increase the continuity of temporal coverage by maximizing observing time and minimizing the loss of observations due to weather conditions. DATA-ASSIMILATING COMPUTER MODELS Although not instruments per se, computational models linked to observational data are a key requirement for major advances in upper atmosphere research and in space weather "nowcasting" and forecasting.
|
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.