SOHO/EIT CalRoc Intercomparisons

Jeff Newmark, Jean-Marc Defise (EIT)
Ken Dere (LASCO)
Craig DeForest (MDI)
Dominic Zarro (CDS)
Don Mcmullin (SEM)

Run on 16-Oct-97
Latest revision: 06-Oct-1997

Participating Instruments and Observatories:


Background and Scientific Justification

The objective is to improve the EIT flatfield and provide an absolute calibration.

The EIT space optics have been incorporated into a sounding rocket payload. This instrument has been calibrated with the full program which was planned for the SOHO EIT (but truncated by programmatics). Further calibration checks will be applied immediately before and after launch. This Intercal would be special observations during the approximately 2-3 hours around the time of the EIT CalRoc launch from White Sands.

Overview of Observing Campaign


The EIT Calroc is currently scheduled to launch at 18:10 on October 16. This program will run for a few hours before and after the launch, see the detailed instrument plans for specific timing. EIT requires telemetry submode 6 for this.

Instrument participation:

Participation is requested from, LASCO, EIT, SEM, MDI, and CDS.

EIT (Contact: Jeff Newmark, Jean-Marc Defise)
This is the main instrument for this ICAL. The rocket flight will provide an improved flat field and an absolute calibration. EIT - 17:00 synoptic set, 4 waves, full resolution, full field

17:30-19:00 4 waves, full field, 2x2 binned

19:00 normal synoptic set

LASCO (Contact: Ken Dere)
LASCO will provide information concerning the outer corona with a C1 FeX image at about 17:25.

MDI (Contact: Craig DeForest)
MDI will provide a good signal to noise full disk magnetogram. This will require a sequence of images to co-add:

MDI - sequence = full disk magnetograms.

CDS (Contact: Dominic Zarro)
CDS will take quiet sun raster covering approximately 24"x32" disk center field of view. Lines will include HeII, FeXII, FeXIV, MgIX and other lines within the 1-2 million degree temperature range. This will provide an excellent cross calibration.

CDS - 16:00-17:30 NIS 4'x4' context study (temperature, emission measure diagnostics) INCLUDE HeII 304 in second order

17:30-18:50 GIS study - 24"x32" (4"x4" slit)

18:50-20:10 GIS study - 24"x32" (4"x4" slit)

SEM (Contact: Don McMullin)
The SEM measures full disk 304 intensities and provides a good comparison with EIT. In addition to the SOHO SEM, there will also be an SEM piggyback aboard the EIT Calroc.This will provide a tool for atmospheric corrections. These observations provide an excelent cross-calibration of the two instruemtns and a fundamental point for the long term comparisons.

SOHO SEM - 15 second full resolution package.