HDPWS

SOHO Coronal Diagnostic Spectrometer Data

(1996). SOHO Coronal Diagnostic Spectrometer Data. [Data set]. SOHO Science Archive at the European Space Astronomy Centre.

ResourceID
spase://ESA/NumericalData/SOHO/CDS/SSA_SDAC

Description
The CDS (Coronal Diagnostic Spectrometer) is designed to probe the solar atmosphere through the analysis of spectral emission lines in the extreme ultraviolet wavelength range 15.0-80.0 nm. Observations of the absolute and relative intensities of selected lines, and line profiles, allows the derivation of temperature, density, flow and abundance information for the plasmas in the solar atmosphere. The CDS will provide simultaneous coverage of large wavelength bands combined with temporal resolution down to 1 s. The spatial resolution is 2 arcsec over a field of view of 4 arcmin, which can be pointed anywhere on the sun and the low corona. Wavelength ranges for normal incidence are 31.0-38.0 nm and 51.7-63.3 nm. For grazing incidence, the wavelength ranges are 15.5-22.4, 26.1-34.6, 39.5-49.6, and 66.2-78.7 nm. Slit choices are 2x2, 4x4, 2x240, 4x240, 8x50, and 90x240 arcsec. Spectral resolving power is 3,500 to 12,000 depending on wavelength. The instrument generates far more data than can be transmitted in the telemetry available. Therefore, data are compressed and selected; only the portions of the spectrum desired by the current program are returned. The instrument consists of a Wolter 2 telescope, a flat scan mirror, a slit assembly, and two spectrometers; one for normal incidence and one for grazing incidence. For normal incidence a wavelength-dispersed image is produced at a two-dimensional detector. With a rotation of the scan mirror, two-dimensional images in all of the observed lines can be built up very quickly. For wavelengths less than approximately 30.0 nm, a grazing incidence system is used. The spectrum is dispersed onto four detectors placed along the Rowland circle. Such a system has no imaging capability, so for imaging a pin-hole slit is used, with the mirror performing a raster scan in one dimension. In the other dimension the slit itself is scanned. This information is from the paper ``The Coronal Diagnostic Spectrometer for the Solar and Heliospheric Observatory'' by R. A. Harrison and E. C. Sawyer (Proceedings of the First SOHO Workshop, ESA SP-348, pp. 17-19, November 1992).

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Version:2.6.0

NumericalData

ResourceID
spase://ESA/NumericalData/SOHO/CDS/SSA_SDAC
ResourceHeader
ResourceName
SOHO Coronal Diagnostic Spectrometer Data
AlternateName
SOHO CDS Data
ReleaseDate
1996-04-30 00:00:00
RevisionHistory
RevisionEvent
ReleaseDate
2024-05-22 00:08:46
Note
Updated PublicationInfo
RevisionEvent
ReleaseDate
2024-06-02 00:08:46
Note
Changed NamingAuthority from NASA to ESA; Updated Contact; Updated PublicationInfo (PublicationDate is the date when the first CDS fits was created.)
Description
The CDS (Coronal Diagnostic Spectrometer) is designed to probe the solar atmosphere through the analysis of spectral emission lines in the extreme ultraviolet wavelength range 15.0-80.0 nm. Observations of the absolute and relative intensities of selected lines, and line profiles, allows the derivation of temperature, density, flow and abundance information for the plasmas in the solar atmosphere. The CDS will provide simultaneous coverage of large wavelength bands combined with temporal resolution down to 1 s. The spatial resolution is 2 arcsec over a field of view of 4 arcmin, which can be pointed anywhere on the sun and the low corona. Wavelength ranges for normal incidence are 31.0-38.0 nm and 51.7-63.3 nm. For grazing incidence, the wavelength ranges are 15.5-22.4, 26.1-34.6, 39.5-49.6, and 66.2-78.7 nm. Slit choices are 2x2, 4x4, 2x240, 4x240, 8x50, and 90x240 arcsec. Spectral resolving power is 3,500 to 12,000 depending on wavelength. The instrument generates far more data than can be transmitted in the telemetry available. Therefore, data are compressed and selected; only the portions of the spectrum desired by the current program are returned. The instrument consists of a Wolter 2 telescope, a flat scan mirror, a slit assembly, and two spectrometers; one for normal incidence and one for grazing incidence. For normal incidence a wavelength-dispersed image is produced at a two-dimensional detector. With a rotation of the scan mirror, two-dimensional images in all of the observed lines can be built up very quickly. For wavelengths less than approximately 30.0 nm, a grazing incidence system is used. The spectrum is dispersed onto four detectors placed along the Rowland circle. Such a system has no imaging capability, so for imaging a pin-hole slit is used, with the mirror performing a raster scan in one dimension. In the other dimension the slit itself is scanned. This information is from the paper ``The Coronal Diagnostic Spectrometer for the Solar and Heliospheric Observatory'' by R. A. Harrison and E. C. Sawyer (Proceedings of the First SOHO Workshop, ESA SP-348, pp. 17-19, November 1992).
PublicationInfo
Authors
The CDS Consortium: Rutherford Appleton Laboratory (UK); Mullard Space Science Laboratory (UK); University of Oslo (Norway); NASA Goddard Space Flight Center (USA); Max Planck Institutes (Germany); Physikalisch-Technische Bundesanstalt (Germany); University of California, Berkeley (USA)
PublicationDate
1996-04-30 00:00:00
PublishedBy
SOHO Science Archive at the European Space Astronomy Centre
Contacts
Role Person StartDate StopDate Note
1. PrincipalInvestigator spase://SMWG/Person/Andrzej.Fludra
2. FormerPI spase://SMWG/Person/Richard.A.Harrison
3. HostContact spase://SMWG/Person/Jack.Ireland
4. MetadataContact spase://SMWG/Person/Seiji.Yashiro

InformationURL
Name
The CDS Instrument paper
URL
Description
The CDS Instrument paper ``The Coronal Diagnostic Spectrometer for the solar and heliospheric observatory'' by Harrison et al. 1995.
PriorIDs
spase://NASA/NumericalData/SOHO/CDS/VSO_SDAC
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
SOHO Science Archive at European Space Astronomy Centre
URL
Style
Search
Format
FITS
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
NASA Solar Data Analysis Center via Virtual Solar Observatory
URL
Style
Search
Format
FITS
ProviderProcessingLevel
CALIBRATED
InstrumentIDs
MeasurementType
Spectrum
TemporalDescription
TimeSpan
StartDate
1996-01-19 20:15:57
StopDate
2014-09-05 10:06:48
ObservedRegion
Sun
ObservedRegion
Sun.Corona