SUMER observing details :

Various sequence parts are proposed to cover the behaviour of the selected spectral lines. The long-duration sequences of 1D measurements are chosen to measure behaviour of the spectral line intensities, velocities and widths. The fast changes of the most pronounced lines will be investigated by using of the short-duration sequences. The 100 duty cycle is planned for the measurements with the maximal exploitation of the available telemetry channel throughput.

SUMER 1 spectral lines set :

  
Table: The SUMER 1 spectral line set : wavelength interval : 1020.5 -- 1041.5 Å.

Spectral image positions : 6 spectral images, each 25pixels wide :

1/ 1025.4 Å : two 25pixels windows = 50pixels wide : H I Ly line core

2/ 1027.430 Å : one 25pixels window : O I line

3/ 1036.4-1038.6 Å : two 25pixels windows = 50pixels wide : C II, O VI lines

4/ 520.666 Å (1041.133 Å) : one 25pixels window : Si XII line, (2nd order)

SUMER 2 spectral lines set (SUMER CDS co-alignment) :

The most favourite common spectral line (He I 584 Å), observable with both SUMER and CDS instruments, was selected for the simultaneous measurements. The reason is to get the highest possible post-facto determination of the SUMER slit position within the CDS FOVs (the post-facto alignment).

  
Table: The SUMER 2 spectral line set : wavelength interval : 583.76 -- 584.89 Å.

Spectral image positions : 2 spectral images, each 25pixels wide :

1/ 2x584.33 Å : two 25pixel windows = 50pixels wide : He I line in the second order

SUMER RSC run (SUMER MDI and TRACE co-alignment) :

The special long-term SUMER rear slit camera (RSC) measurements carried out before the simultaneous SUMER/CDS/MDI/(EIT) and TRACE observations are proposed for the post-facto alignment of the SUMER slit position with the MDI and TRACE FOVs. The SUMER RSC photospheric intensity image, constructed from the RSC measurements taken without the solar rotation compensation, would be later co-aligned with the MDI and TRACE continuum images that will be taken at least few seconds after the end of SUMER RSC data acquisition. We expect to identify some pores which could help us to improve specification of the SUMER slit position better than expected intrinsic 5'' in the MDI and TRACE continuum images.

The matrix of at least 110x120 pixels (55 x120 ) with the real resolution of about 2 and the SNR of about 4000 should be constructed on the ground. The proposed minimal parameters of the RSC run are :

SUMER EIT co-alignment :

In principle, this alignment can be made in two ways. In both ways the described SUMER CDS alignment has to be used to specify the SUMER slit in the CDS 2D FOVs. Then only the CDS EIT co-alignment can be performed in order to obtain the required SUMER EIT alignment.

1. The first way is based on the comparison of the CDS He I 584 Å 2D movies and rasters (described below) and the simultaneously taken EIT He II 304 Å bandpass images. The correlation of intensities of these lines was reported to be high - r>0.9 (Andretta et al., 1997).
2. The second approach is to exploit the CDS 2D rasters taken during the CDS density-sensitive diagnostics part (see CDS sequence part 6) in which also in the He II 304 Å line is included. These CDS rasters should be acquired simultaneously with the EIT imaging in the same line.

Both types of measurements were included to the present JOP, namely 584 Å line was included to all CDS sequence parts and the 304 Å line is proposed to be used in the CDS sequence part 6, but together with the 584 Å line.

SUMER auxiliary measurements :

Flat-field frames taken before and after the JOP runs and the information on the temporal behaviour of the SUMER internal temperature are essential for the precise data reduction including the estimation of noise (Curdt et al., 1997a).

Summary of the SUMER observing run sequences :

The brief description of the proposed procedure of the SUMER sequence parts, together with the timing, are given below in the following tables :

 
Table 3: The brief description of the SUMER sequence parts.

 
Table 4: The timing and basic parameters of the SUMER sequence parts.