5 Examples of results

Although the focal instrumentation is still under development (see Sect. 6), the performances already meet the requirements of many scientific programs. We present some examples.

5.1 Fast chromospheric dopplergrams

Figure 3: H$_{\alpha }$ filament observed on 14 May 2000. Line center intensity (top) and Doppler velocity (bottom) computed at $\pm 24$ pm with the bisector method. The field of view is $150\hbox {$^{\prime \prime }$ }\times 123\hbox {$^{\prime \prime }$ }$( Courtesy S. Régnier).

1) During a ground-space campaign with SOHO, filaments were observed in H$_{\alpha }$ on May 14, 2000 with optics A. We present in Fig. 3 a line-center image and a dopplergram at $\pm 24$ pm. Detailed analysis, including power spectra of oscillations, are performed in comparison with CDS results (Régnier et al. 2001).

2) Penumbral waves and umbral flashes have been observed on Aug. 21, 2000 with optics C in CaII 8542 Å. Using a 23 mn time series, Tziotziou et al. (2002) investigate their spatial and temporal behaviour. The MSDP is well adapted to fast chromospheric events.

5.2 Stratification of magnetic fields

Figure 4: Longitudinal magnetic field deduced from MSDP observations in the NaD1 profile on May 9, 2000. Bisector method, at $\pm 16~\rm pm$. Polarization analysis with grid in the primary focus (Sect. 3.6). The field of view is $138\hbox {$^{\prime \prime }$ }\times 120\hbox {$^{\prime \prime }$ }$. ( Courtesy J.-M. Malherbe).

On May 9, 2000, an active region was observed in the NaD1 line, with polarization analysis and optics C. Figure 4 shows the line-of-sight magnetic field derived from the bisector method at $\pm 16$ pm. Figure 5 presents some I and V profiles along the line ab crossing two spots of opposite polarities. Magnetograms have been computed also for $\pm 8$ pm and $\pm 24$ pm. They provide the magnetic field at different levels of the photosphere and the low chromosphere. By using NLTE response functions, Eibe et al. (2002) compared the vertical gradients with the gradients deduced from force-free extrapolations of the field into the corona.

5.3 Ground-space observations

In addition to the observations mentioned in Sect. 5.1, several campaigns were coordinated with SOHO, TRACE and YOHKOH.

1) Arch Filament Systems were observed on Sep. 10, 1998 and analysed in terms of a cloud model (Mein P. et al. 2000). TRACE, VTT-MSDP and THEMIS-MSDP data were used to determine temperatures and densities (Mein N. et al. 2001).

2) A coordinated campaign with SOHO/CDS and SUMER was devoted to filament absorptions on May 5, 2000 (Schmieder B. et al. 2001). Results were obtained about the opacity of Lyman continuum compared to H$_{\alpha }$.