Paper Plate Education Video Excerpts: Satellite Tracking BowlThe following pictures and narration are excerpted from the Paper Plate Astronomy video. With the Satellite Tracking Bowl you plot the predicted path of visible satellites on the inside dome of a bowl. Then you use the bowl as an alignment tool to face the direction and anticipate the path of the satellite crossing overhead. Conveniently, foam bowls such as Hefty brand have 36 decorative scallops around their perimeters, so each scallop represents 10 degrees. You can calibrate your horizon into 360 degrees of azimuth... Or you can label the cardinal points --North, South, East, and West-- and draw features of your local horizon similar to the Sunrise Sunset activity. Notice here we have on the near edge the zero degree mark for North and on the opposite side is South. One bowl you will cut in half to make a tool for plotting the satellites positions onto a second bowl, which is the end product. Envision yourself standing under this bowl or dome of stars overhead. You want to mark the angular amount from the horizon (or zero degrees) up to your zenith, overhead at 90 degrees... Hold a protractor against the edge of the halved bowl and mark zero-to 90 degrees near that edge... Then label those hash marks zero through 90 degrees. Obtain satellite data for your location from the Heavens Above website... It lists satellite name, when the satellite pass starts, maximum altitude, and when satellite visibility ends. Heres an example of how you will plot the satellite position. Place the half-bowl inside the whole one and rotate it so that the zero-degree mark is near the desired azimuth, or compass heading. Then go up to the desired altitude and mark that spot on the bottom bowl. From this evenings predictions we see the object named Meteor 1-29 Rocket, magnitude 2.5, is first seen at this time, 10 degrees of altitude in the south southeast. Heres the southeast ... so this is south southeast...place the bowl there...and make a mark at 10 degrees. Next, this satellite reaches a maximum altitude of 88 degrees toward the north northeast, which is essentially overhead. You can plot this...heres NNE..88 degrees. The satellite pass ends at 10 degrees in the north northwest...which you again plot. Notice how sometimes the full duration of the satellite pass can not be seen due to obstructions nearby. Draw a line connecting these points... and label the path with satellite name and starting time when the satellite first appears...When you are done you have an entire evenings worth of predicted passes represented visually on the bowl. To use it, you hold the bowl overhead, align yourself in the proper direction, and look near the predicted spot in the sky....
|
Copyright ©2012 Chuck Bueter. All rights reserved. |