Solar Images and Spectra from the Yohkoh SpacecraftEntry ID: Yohkoh-01
Abstract: This data set consists of data from all four instruments on board the
Yohkoh spacecraft (formerly called Solar-A). Data are held as
proprietary for two years after collection (although more recent data
may be analyzed in approved collaborations with science team members)
and then released, so the public data set will grow periodically.
Anyone interested in collaboration is invited to contact
... Prof. Y. Uchida, Yohkoh Science Committee Chairman.
A data users' guide is available at:
The objective of Yohkoh (Japanese for sunbeam) is to study the
high-energy radiations from solar flares (hard and soft X-rays and
energetic neutrons) as well as quiet structures and pre-flare
conditions. The mission is a successor to Hinotori, a previous
Japanese spacecraft flown at the previous solar activity maximum in
1981. Yohkoh is a three-axis stabilized observatory-type satellite in
a nearly-circular Earth orbit, carrying four instruments: two imagers
and two spectrometers. The imaging instruments have almost full-Sun
fields of view, to avoid missing any flares on the visible disk of the
Sun. The Hard X-ray Telescope (HXT) is a multi-grid synthesis type
with a spatial resolution of 7 arcsec, operating in the 20 - 80 keV
range. The SXT uses grazing-incidence optics and achieves 4 arcsec
spatial resolution, operating in the 0.1 - 4 keV range and using 1024
x 1024-pixel CCDs. US solar physicists at Lockheed Palo Alto Research
Lab. are collaborating in the Soft X-ray Telescope (SXT) production
and data analysis. There is also a continuum Wide-Band Spectrometer
(WBS) for X-rays and gamma-rays from 3 keV to 20 MeV (also sensitive
to neutrons) and a Bragg Crystal Spectrometer (BCS) for the X-ray
lines Fe XXV, Fe XXVI, Ca XIX, and S XV. Approximately 50 Mbytes of
data are accumulated per day, and stored on an on-board tape recorder
with 10.5 Mbyte capacity. The Yohkoh mission is a cooperative mission
of Japan, the US, and England.
Data tape cartridges (8-mm) contain data from all four instruments in
a format such that all data may be conveniently intercompared. A
software package YODAT, written in IDL (Interactive Data Language, a
product of RSI Systems), is distributed with the data to facilitate
use. Users are encouraged to get the latest version of the software
via computer network connection, however; to do this, send a request
to the Internet address firstname.lastname@example.org.
Responsibility for data from the four instruments is not centralized;
rather there is a contact person for each instrument. The contacts
for the four instruments are: BCS - R. Bentley (email@example.com);
HXT - T. Kosugi (firstname.lastname@example.org..jp); SXT - J. Lemen
(email@example.com); WBS - M. Yoshimori
(firstname.lastname@example.org). There is a comprehensive "Yohkoh
Analysis Guide" to using the data and YODAT software package, written
Access to Yohkoh is through the Solar Data Analysis Center
including access to Yohkoh SXT data and movies.
Data Set Citation
Dataset Originator/Creator: NASA/GSFC/SDAC
Dataset Title: Solar Images and Spectra from the Yohkoh SpacecraftOnline Resource: http://umbra.gsfc.nasa.gov/yohkoh_archive.html
Start Date: 1991-09-01Stop Date: 1993-03-06
SUN-EARTH INTERACTIONS > SOLAR ACTIVITY > CORONA HOLES
SUN-EARTH INTERACTIONS > SOLAR ACTIVITY > SOLAR ACTIVE REGIONS
SUN-EARTH INTERACTIONS > SOLAR ACTIVITY > SOLAR FLARES
SUN-EARTH INTERACTIONS > SOLAR ACTIVITY > SOLAR IMAGERY
SUN-EARTH INTERACTIONS > SOLAR ACTIVITY > SOLAR X-RAY EMISSIONS
SUN-EARTH INTERACTIONS > SOLAR ACTIVITY > SUNSPOTS
ISO Topic Category
Role: DIF AUTHOR
Email: David.A.Batchelor at nasa.gov
NASA Goddard Space Flight Center Code 561.0
Province or State: MD
Postal Code: 20771
Role: TECHNICAL CONTACT
Email: lemen at sag.lmsal.com
Email: uchida at dept.astron.u-tokyo.ac.jp
University of Tokyo Institute of Astronomy Faculty of Science
Province or State: Mitaka
Postal Code: 181
Culhane, J. L., et al., "The Bragg Crystal Spectrometer for Solar-A,"
Solar Phys., v. 136, 89 (1991).
Kosugi, T., et al., "The Hard X-ray Telescope for Solar-A," Solar Phys.,
v. 136, 17 (1991).
Morrison, M. D., "Yohkoh Analysis Guide Ver. 2.00," LPARL document
LMSC-P098510, Jan. 26, 1994.
Tsuneta, S., et al., "The Soft X-ray Telescope for the Solar-A Mission,"
Solar Phys., v. 136, 37-67 (1991).
Yoshimori, M., et al., "The Wide Band Spectrometer for the Solar-A Mission,"
Solar Phys., v. 136, 69-88 (1991).
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Creation and Review Dates
Last DIF Revision Date: 2005-08-01