Scope Diagram Astrocamera.Net - Astrophotography by Dave Kodama

Geostationary Satellites 2


This is a followup time-lapse animation of geosynchronous satellites which covers a longer 9-hour span (~ 19:30 - 04:30 PDT, starting on the evening of October 1st. Geostationary satellites are marked with vertical arrows to make them easier to see on the video, which should be viewed at the highest resolution allowed by your link (1080 recommended). Satellites which have orbits off the equatorial plane can also be seen passing through the frames, with the more obvious ones marked with arrows near the points where they can first be seen.



(Click on photo to see Geosat video)
 

The earlier start time and higher elevation in the sky (about 45° elevation) shows the satellites being eclipsed by the shadow of the earth soon after the video sequence starts. If you watch carefully, you can see the shadow first darkening the left (easternmost) group of satellites and progressing westward, followed by reappearance in the same order. Later in the video, most of the satellites completely disappear as the sun illumination angle becomes unfavorable for lighting up the satellites. Prior to this, some satellites can be seen to "flare" for a few frames as the sun glints off a polished flat surface.

 

Late in the video, the Orion Nebula, M42 can be seen passing through the field of view. A plane also zips through the field of view.

 

Technical Information

 

The movie was created by using a Nikon D700 DSLR on a stationary tripod and a zoom lens set at 135mm focal length, f/4.5. The camera was set for ISO 6400. Frames were taken 75 seconds apart using the camera's built-in intervalometer, with 30 seconds used for the actual exposure, and 30 more for an in-camera dark-frame subtraction. This eliminated the "hot" pixels which might have been mistaken for stationary satellites. The frames were taken with the camera level to the equatorial plane.

 


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