An astronomical object is Ascending when it is moving north in latitude with respect to the celestial sphere or "up" with respect to the usual ground map. Descending means moving south or "down" with respect to the map.
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The best way to remember this is to think of a map. Normally maps are held with north on top, so going "down" on the map is going from north to south.
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The definition of the word period
in this case is a round of time marked by the recurrence of some phenomenon or occupied by some recurring process or action.
So, the "orbital period" is a round of time marked by the recurrence of the orbit of an earth satellite -- in other words, it's the time it takes for a satellite to complete one revolution around the Earth.
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Historically OSCAR uplink (transmit to) and downlink (receive from) frequencies were designated using single letter codes.
Mode A: 2 m uplink / 10 m downlink
Mode B: 70 cm uplink / 2 m downlink
Mode J: 2 m uplink / 70 cm downlink
New uplink and downlink designations use sets of paired letters following the structure X/Y where X is the uplink band and Y is the downlink band.
Reference: http://en.wikipedia.org/wiki/OSCAR#Mode_designators
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Historically OSCAR uplink (transmit to) and downlink (receive from) frequencies were designated using single letter codes.
New uplink and downlink designations use sets of paired letters following the structure X/Y where X is the uplink band and Y is the downlink band.
Reference: http://en.wikipedia.org/wiki/OSCAR#Mode_designators
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The paired letters U/V indicate the uplink (receive) and downlink (transmit) bands that the satellite uses, where:
See Wikipedia's page on amateur radio satellite a complete list of mode designators.
The order is uplink/downlink, which from the perspective of the satellite is receive/transmit.
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Satellite transponders are power-sharing. If one signal received at the satellite is stronger than the others, all other retransmitted signals will get a smaller portion of the available power.
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Transponder link designators:
Frequency | Designator |
---|---|
21Mhz | H |
29Mhz | T |
145Mhz | V |
435Mhz | U |
1.2Ghz | L |
2.4Ghz | S |
5.7Ghz | C |
10.5Ghz | X |
24Ghz | K |
-w3mit
Study Hint: Think "(L)ittle and (S)mall" for 23 and 13 cm. “LS” looks like 23 and "ls" looks like 13.
See the mode designator chart
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Faraday rotation is the change in radio wave polarization due to the presence of a magnetic field, while spin modulation is also a polarization change, but due to the rotation of the signal source or of an object that reflects the radio wave, such as a satellite. Both effects can result in rotating radio waves, which can be minimized by a circularly polarized antenna.
Memory trick: “spin” in a ”circular” motion.
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By calculations using the Keplerian elements for the specified satellite.
Keplerian elements are the inputs to a standard mathematical model of spacecraft orbits. Most often the calculations needed would include the Keplerian elements, an accurate time clock and your current location.
AMSAT Info on Keplerian elements
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A geosynchronous satellite is actually moving along its orbit just like any other satellite. It is at a height and position such that this orbital rotation matches the earth’s rotation and so it appears to be stationary.
LEO means "Low Earth Orbit" and HEO means "Highly Elliptical Orbit" and both are not relevant to this question. A geomagnetic orbit is not a thing, I think.
Hint: It’s the only question with stationary in it.
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