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uhoh
uhoh
11:58 PM
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Q: How can one know that Chang'e-4 was in "locked to the Queqiao" from this SDR spectrogram?

uhohDeep space SDR enthusiast and amateur radio operator Edgar Kaiser @df2mz's 28-Dec-2018 tweet says: Chang'e 4 in lunar orbit last night on 8479.77 MHz. The spacecraft seems to be locked to the Queqiao relay satellite at the moon-earth L2 point during most of the passes. Short unlocked interval...

radio-communication amateur-radio
also, is spectrogram the correct word for this kind of frequency vs time histogram, or is there a better term for it?
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Q: Understanding shape of DSN's 'kinky uplink protocol' keeping frequency in coherent transponder's optimum bandpass?

uhohThis tweet by deep space SDR enthusiast and amateur radio operator Edgar Kaiser @df2mz shows a squiggly tone from MRO. Mars Reconnaiscance Orbiter (MRO) X-band downlink. The signal shows this kinky behavior due to a specific uplink protocol keeping the uplink signal frequency within the opti...

orbital-mechanics radio-communication deep-space-network doppler-ranging delay-doppler
 

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