ResourceName
SOHO/VIRGO/LOI Data
DOI
https://doi.org/10.48322/bss7-df92
ReleaseDate
2024-05-29 00:08:46
RevisionHistory
RevisionEvent
ReleaseDate
2024-05-29 00:08:46
Note
Metadata created by SY
RevisionEvent
ReleaseDate
2024-06-04 00:08:46
Note
Updated the PublicationInfo and Contact; The PublicationDate is the date when the first data was created.
RevisionEvent
ReleaseDate
2024-06-13 00:08:46
Note
Added DOI by SY
Description
The SOHO/VIRGO/LOI Level 1 data. The Luminosity Oscillations Imager (LOI) is a part of the Variability of Solar Irradiance and Gravity Oscillations (VIRGO) aboard the Solar and Heliospheric Observatory (SOHO).
The instrument consists of a Ritchey-Chrétien type telescope making an image of the Sun onto a silicon detector. The telescope has a focal length of 1300 mm and is imaging the Sun through a 5 nm wide bandpass interference filter at 500 nm. The detector resolves the solar disk into 12 spatial elements allowing the detection of solar modes of degree lower than 7. The detector consists of a photodiode array custom built to specification. It has 12 scientific pixels and 4 guiding pixels. The shape of the scientific pixels is optimized to detect low degree modes of l < 7. The guiding pixels are 4 quadrants of an annulus with an equivalent inner and outer radius of 0.95 and 1.05 solar radii, respectively. The error signals are fed back to two piezoelectric actuators that move the secondary mirror around its vertex. The actuators provide both coarse and fine pointing. The total range is ± 7.5 arc min. The -3dB bandwidth of the servo control loop is 10 Hz. The guiding keeps the Sun centered on the detector with an accuracy better than 0.1". The photocurrent of each pixel diode is processed by I/V converters in zero-bias configuration. It is then digitized by separate Voltage-To-Frequency converters for each channel. The sampling interval and integration time is 60s, the resolution is 20 bit. The guiding pixels are sequentially read out by the common VIRGO data acquisition system, with 16 bit precision.
This information from the ESA website (https://sci.esa.int/web/sci-fmi/-/35985-soho-virgo-loi).
PublicationInfo
Authors
The VIRGO Team: Physikalisch-Meteorologisches Observatorium Davos/World Radiation Centre (Switzerland); Norwegian Space Centre (Norway); ESA European Space Research and Technology Centre (Netherlands); Observatoire de Nice (France); Institut Royal Météorologique de Belgique (Belgium); Instituto de Astrofísica de Canarias (Spain)
PublicationDate
1997-11-03 00:00:00
PublishedBy
SOHO Science Archive at the European Space Astronomy Centre
Contacts
InformationURL
Name
VIRGO: Experiment for helioseismology and solar irradiance monitoring
URL
Description
The VIRGO Instrument paper
InformationURL
URL
Description
The VIRGO/LOI Instrument
InformationURL
URL
Description
The VIRGO/LOI Instrument