SOHO Intercalibration Joint Observing Program
Updated: 26 November 2003
SOHO/CALSO-6 Cross Calibration & Co-Measurements
The SOHO CELIAS/SEM has operated continuously since its activation
December, 1995. The next underflight calibration of the CELIAS/SEM
instrument is scheduled December 5, 2003.
Calibration underflights for SOHO and Solar Atmosphere Investigations
(CALSO-6) is a multi-year program to provide the absolute solar
irradiance in the extreme ultraviolet (EUV) wavelength region. The data
obtained will provide verification of the Solar Heliospheric Observatory
(SOHO) Solar EUV Monitor (CELIAS/SEM) calibration.
To supplement the SEM data, and the SOHO inter-calibration, the spectral
emissions from key solar EUV lines and continuum will be measured on the
CALSO rocket by an Optics Free Spectrometer (OFS). All instruments on the
CALSO-VI rocket payload make full disk observations and include the
following instruments in addition to the ROCKET/SEM.
1. Rare gas ionization cell used to obtain a direct measurement of the
absolute integral flux shortward of the ionization limit of the rare gas
of interest (neon < 57.5 nm).
2. Double ionization cell used to obtain a direct measurement of the
photoionization rate of in-flowing interstellar helium (< 50.4 nm).
3. Silicon photodiodes with aluminum and titanium filters used to
continuously monitor and characterize the solar EUV flux as a function of
Launch is currently scheduled for December 5, 2003, at 19:30 UT.
This is a dual-launch coordinated with the launch of the EIT CalRoc II
ICAL Instrument teams will have access to launch day activities real-time
via live web cast of the mission.
CELIAS/SEM will provide continuous measurements at full resolution (15s)
through the complete mission. There are no mission specific requirements
for the CELIAS/SEM.
EIT - EIT synoptic sets (full-resolution, full-field of view images in
all four wavelengths) before, during, and after the rocket flight will be
scheduled (3 synoptic sets requested, two minimum). NRT commanding will
be necessary to allow for a launch slip in the rocket program.
CDS - Program operation USUN_6 is requested to be run during the planned
coordinated observations. USUN_6 will begin at T-6 hours to be centered
around the planned launch of the dual sounding rocket mission. The
observation will run for 13 hours. No real-time commanding is required
during the sequence. There are no plans to change the CDS observation
schedule in the case of minor delays of the rocket launch.
- TBA -