Wednesday, 10 May 2006

Lacrosses and IGS 1B, and veil clouds

Summer has arrived: it is very sunny the past week, and I finally can leave my jacket at home and walk about in shorts and shirt, even observe in a T-shirt.

Nevertheless, sky conditions are not optimal. There is a thin veil in the skies, which in an urban environment like Leiden (and with moonlight now entering as well) is deadly to photographic observations. This was shown again last night: sat passes that were visible with the naked eye, drowned in the background fog on the photographic image. So I have seen Lacrosse 2, Lacrosse 3 and IGS 1B, but can only present positions for Lacrosse 3 as the other images did not yield measurable trails. The result on Lacrosse 3 was obtained in strong twilight before the thin veil clouds arrived. The image too is fogged, by twilight, but did yield a measurable trail and enough stars so I measured it and reported it.

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