| L. Feng, B. Inhester, S.K. Solanki, T. Wiegelmann, B. Podlipnik,R.A. Howard |
| Stereoscopic Reconstructions of Coronal Loops and Plumes |
| L. Feng, B. Inhester, S.K. Solanki, T. Wiegelmann, B. Podlipnik et al. |
| We present the 3D reconstruction results of coronal loops and polar plumes from SECCHI/EUVI image pairs. |
| Study of the Propagation of CMEs in the Inner Heliosphere Using SMEI and SECCHI-HI Data |
| D. F. Webb, T. A. Howard, and J. S. Morrill |
| The geometric and kinematic characteristics of interplanetary coronal mass ejections (ICMEs) are investigated using data obtained by the LASCO coronagraphs, the Solar Mass Ejection Imager (SMEI) and the SECCHI imaging experiments on STEREO. The early evolution of CMEs can be tracked by the LASCO C2 and C3 and SECCHI COR1 and COR2 coronagraphs, while the HI and SMEI instruments can track them through the inner heliosphere. The HI fields-of-view (4-90 deg) lie within the SMEI field-of-view (>20 deg to all sky) and, thus, both instrument sets can observe the same ICME. We present preliminary results on observations and modeling of the geometry and kinematic evolution for several ICMEs observed by both SMEI and SECCHI over the last 1.5 years. Essential to the analysis procedure is an understanding of the effects of projection across large distances, which are not generally required for events observed closer to the Sun. |
| Getting the most out of the SECCHI images |
| Guillermo Stenborg - Angelos Vourlidas - Russ Howard |
| The standard image reduction routines developed to process the data products provided by the different SECCHI instruments perform well. However, further processing is often needed to reveal in more detail the structure and time evolution of dynamic events (e.g., running difference, base difference, unsharp masking, etc.). In this presentation I'll introduce several ideas I devised to work around the intrinsic issues the community normally have to deal with when trying to extract morphological information out of the SECCHI images. In particular, a new technique was recently introduced to clean and enhance the SOHO EIT images (Stenborg et al., ApJ, 674, 1201-1206, 2008). The technique has been now successfully adapted to work on EUVI images as well. Likewise, the original wavelet-based enhancement technique developed to reveal the inner structure of coronal structures in coronagraph data has been adapted to work on the SECCHI CORs instruments. As for the Heliospheric Imagers, an empirical approach to minimize the effect of the star field in running difference sequences is in effect. Examples will be shown to assert the effectiveness of the ideas |
| NRL SECCHI Movie Tools & Products |
| Nathan Rich |
| A report on MVI tools for SECCHI data. Examples of synoptic movies available on website. |
| SECCHI Data Status and Archive Plan |
| Nathan Rich |
| Data processing pipeline status; image archive statistics; data distribution status; calibration status; long term archive plans. |
| Measurements of the altitudes of solar filamentd |
| Artzner Guy |
| In addition to that we implemented a correlation program in order to calculate the same results as by visual examination. We measure altitudes within solar filaments located in the common field of view of STEREO-A and STEREO-B. We present static and dynamic measurements. |
| EUVI Event Catalog: An Introduction and Website Tutorial |
| Aschwanden, Wuelser, Lemen, & Nitta |
| We compiled a catalog of flares and CME events observed with EUVI during the first year of the mission (Dec 2006-Jan 2008). It contains a comprehensive list of 178 flare events, down to a threshold of GOES >C1-class or RHESSI >25 keV, annotated with LASCO and COR-1 observations. We give an introduction on the related material available on the website http://secchi.lmsal.com/EUVI/, containing: (1) full-disk contrast-enhanced movies, (2) analgyph weekly movies [before Aug 2007], (3) two-panel movies [after Sept 2007], (4) anaglyph movies of flares, (5) flare quicklook plots with GOES+EUVI light curves, and (6) EUVI event catalog. We give also updates on EUVI analysis (SSW) software available on the EUVI webpage. |
| Radiometric calibration of COR1 |
| William Thompson and Nelson Reginald |
| The co-alignment of the two COR1 telescopes is derived from the star Regulus for the Ahead spacecraft, and from an occultation of the Sun by the Moon for Behind. Observations of the planet Jupiter are used to establish absolute photometric calibrations for each telescope. The intercalibration of the two COR1 telescopes are compared using coronal mass ejection observations made early in the mission, when the spacecraft were close together. Comparisons are also made with the LASCO~C2 and Mauna Loa Solar Observatory Mk4 coronagraphs. |
| CME kinematics in the inner Heliosphere |
| Maloney, S. A., Gallagher, P. T., McAteer, R. T. J. |
| Interplanetary CMEs: A new perspective from HI |
| R. A. Harrison, C.J. Davis, C.J. Eyles, D. Bewsher, J.A. Davies, S. Crothers |
| The HI instruments offer a unique method for studies of CMEs in the heliosphere. Many aspects of so-called ICME topology and properties come from in-situ measurement but we now have the opportunity to test the conclusions of such studies and to extend them to provide a basic view of CMEs in the heliosphere. |
| Two eyes really are better than one: improved comet orbits from stereoscopic observations |
| Karl Battams and Brian Marsden |
| The multiple viewpoints offered by the STEREO and SOHO spacecraft allow us to determine significantly improved comet orbits. Here we will present and discuss our results in determining the improved orbital elements of Kreutz-group comets from the combinations of camera and spacecraft observations now available to us. |
| Building the SECCHI CME List |
| E. Robbrecht (GMU), A. Vourlidas (NRL), D. Berghmans (ROB), B. Nicula (ROB), R. Howard (NRL) |
| Manipulating 3D Density Cubes |
| Thernisien, A and Antunes, A. |
| We will briefly demo many of the renderers, widgets, visualizers, and model tools available for 3D manipulation within NRL's SolarSoft library. Using the tools, anyone can create fluxrope and other models, manipulate them as 3-D wireframes, render them from any position (including observed STEREO positions), overlay with actual data, create flyby movies, and save as FITS objects for sharing with others. We also provide a handout so you can use these at your own workplace. |
| CME tracking in the Heliospheric Imagers |
| J. A. Davies, A. Rouillard, C. J. Davis, R. A. Harrison, C. J. Eyles, D. Bewsher, S. R. Crothers |
| Rolling backgrounds for HI |
| Stephen Crothers |
| Looking at how to make minima based backgrounds allowing for the roll data from the spacecraft. |
| Pointing Calibrations of the HI Telescopes |
| D. Bewsher, D. Brown, C.J. Eyles, C.J. Davis, R.A. Harrison, S.R. Crothers, J.A. Davies |
| COR1 Faint Feature Measurements |
| Shaela I Jones, Joseph Davila |
| We present measurements of faint rising density enhancements seen in the COR1 coronagraph, and report on attempts to combine these observations with COR2 and EUVI. |
| The Kinematics of a globally propagating disturbance in the chromosphere and low corona |
| Long, David M.; Gallagher, Peter T.; McAteer, R.T. James; Bloomfield, D. Shaun |
| Terrestrial Relations Observatory (STEREO). We show for the first time that an impulsively generated propagating disturbance has similar morphology and kinematics through the chromosphere and low corona. The velocity and acceler- ation of the pulse were found to be nonlinear in all four EUVI passbands (304 ˚A, 171˚A, 195˚A and 284˚A). In the chromospheric 304 ˚A passband the disturbance −1 within 28 minutes of its launch, vary- ing in acceleration from 76 m s −2 to -102 m s −2 . Comparable values for velocity and acceleration were found in the coronal 195 ˚A passband (vmax ∼262 km s −1 ; -109≤a(t)≤93 m s −2 ), while lower values were found in the high temperature 284 ˚A passband (vmax ∼153 km s −1 ; -32≤a(t)≤23 m s −2 ). In the higher ca- dence 171 ˚A passband, the velocity was found to be highly nonlinear, peaking −1 within 20 minutes of launch, with a variation in acceleration from 816 m s −2 to -413 m s −2 2.5 minutes compared to 10 minutes for the similar temperature response 195 ˚A celeration of a pulse, increasing them by a factor of ∼2 and ∼10 respectively. This implies that previously measured values (e.g., using EIT) may have been underestimated. Our observations are consistent with an impulsively generated fast-mode magnetosonic wave or propagating MHD shock. |
| EUVI calibration and software tools update |
| J-P. Wuelser, J.R. Lemen, N. Nitta |
| Large-scale Coronal Magnetic Field Over Extended Longitudes by STEREO/EUVI |
| Nariaki Nitta |
| In the absence of magnetographs on STEREO, EUVI data with a growing separation angle between spacecraft A and B may at least allow us to locate major active regions and coronal holes in the area not seen from Earth. We compare the PFSS extrapolations and their input synoptic maps with EUVI data to measure how well the model fits the observations close to the Sun. We discuss these comparisons in terms of the predicted and observed solar wind speeds at 1 AU. |