D a v i d A l e x a n d e r
Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto CA
A Week in Paris
Assisted by the jet lag I was able to get up early, something which is normally very difficult for me. I grabbed a couple of croissants from the bakery near the station and headed off on the train while the Sun was struggling to make its way through the overcast sky. I arrived at the Institute around 7 am to find all the doors locked. The French have a different sense of time than I had and since there was nothing I could do I head for a brasserie, ordered a hot chocolate and another croissant and sat down to write the first installment of this Journal. Orsay Ville is a nice little town with lots of the typical French houses I had expected. The walk through town was a pleasant way to start the morning despite the slight drizzle which seems to always be present on my visits to Paris. Unfortunately, the town does not boast a single hotel or Massy-Palaiseau would not feature again in these notes.
I returned to the Institute at 8 am to find the doors still locked but fortunately someone showed up within ten minutes and let me in. I had just enough time to check my e-mail before everyone else showed up. We continued where we left off the day before.
I wish I could report that we made great progress with some startling discoveries, but much of the day was spent in working out how to overlay the images from the different data sets. One of the main problems when working with data from different instruments on different spacecraft is that you need to know, very accurately, where the spacecraft is pointing. To do this you need a fixed reference point and an exact idea of where the center of your image is with respect to this reference point. Typically, we use the center of the solar disk as our reference point and work from there. The problem is made worse by the fact that the two instruments we were using had dramatically different resolution and are at very different locations in space. The TRACE telescope is in Earth orbit and sees scales of 350 km at the Sun whereas SOHO's Extreme ultraviolet Imaging Telescope (EIT) is located about 1 million miles away from the Earth towards the Sun and can't see to better than 1,830 km. This makes the overlay of the two very difficult to get right. So all in all it was much more a day of perspiration rather than inspiration.
The day ended well however as we had a group dinner up in Paris. I had the escargot (snails) and the coeur de filet (steak) which had me worried initially in case it was actually filet de coeur (filet of heart). I told you my French was lousy.