- #1
Samson4
- 245
- 15
Couldnt we put lcd type filters into orbit and modulate sun/moon light to produce high definition radio/tv? Obviously it would need to be large but it seems like it wpuld be much more efficient.
Samson4 said:Couldnt we put lcd type filters into orbit and modulate sun/moon light to produce high definition radio/tv?
Drakkith said:What is an LCD-type filter and what does it have to do with television or radio when placed in orbit?
Okay, after re-reading your thread title and your posts a few times, I think I understand what you are asking. Whew!Samson4 said:Liquid crystal modulation, the type on lcd tvs. Modulating sunlight and using photodetectors to convert it into a digital signal.
Im assuming it takes less energy to twist the liquid crystal molecules than the electromagnetic energy it could modulate.
Samson4 said:Liquid crystal modulation, the type on lcd tvs.
Samson4 said:Modulating sunlight and using photodetectors to convert it into a digital signal.
Samson4 said:Im talking about replacing a radio transmitter with these sunlight modulators. Shouldnt the amount of solar energy be high enough that detectors don't have to be outside?
How would you use reflection?TurtleMeister said:I know what he's talking about. I think reflection would be better than filtering. But I don't see how it could be better than what we already have.
Two problems that come to mind right off are:
1. Would only work when there is no cloud cover.
2. Switching speed of LCDs would need to be improved by many orders of magnitude.
The up-link signal would still need to transmitted using conventional methods. No savings there. And our current satellites are not that inefficient. They use sunlight for power.
Good point. Most radio programs are produced by aliens in orbit, versus TV shows who are produced by aliens on the Earth.Samson4 said:I said radio specifically because you don't need an uplink signal. I'm not sure about T.V though.
My search for "bandwidth" in that patent does not yield any hits...Samson4 said:Looks like someone already tried.
https://www.google.com/patents/US4573214
Samson4 said:Looks like someone already tried.
https://www.google.com/patents/US4573214
berkeman said:Good point. Most radio programs are produced by aliens in orbit, versus TV shows who are produced by aliens on the Earth.
http://nerdreactor.com/wp-content/uploads/2015/09/MEN-IN-BLACK.jpg
View attachment 206026
Glad you liked the humorous response.Samson4 said:Hahaha I read uplink and I thought upload, like with a wifi system in your house. Yeah the uplink would have to be conventional; but, it wouldn't have to be as powerful as conventional methods.
Samson4 said:Hahaha I read uplink and I thought upload, like with a wifi system in your house. Yeah the uplink would have to be conventional; but, it wouldn't have to be as powerful as conventional methods.
Drakkith said:Ah, now I understand what you're trying to do. Instead of sending out a microwave signal from a satellite that carries the information, you're re-directing sunlight and using a liquid crystal panel (or some other device) to switch the outgoing light on or off to modulate it with the information. Receiving stations would be "looking" at the satellite and receiving the modulated sunlight.
It's already amplified on current satellites when it is received prior to processing/re-transmitting.Samson4 said:The uplink could be amplified on the panel. It would be amplified again while modulating solar energy.
berkeman said:
Samson4 said:Is bandwidth a concern for something like radio?
berkeman said:If you read the link I posted, communication satellites have huge BW. That's the only way to make them cost effective.
You might be able to do an amateur satellite project to do a limited number of audio channels (maybe 10?), but commercially you need many TB of BW to make the 100 million dollar launch fee justifiable.
Samson4 said:I only wonder if you could take it close enough to the sun that the signal could be picked up by 50% of the Earth at all times.
You are clearly assuming Amplitude Modulation here. An amplitude modulator requires an input modulating power which is only a bit less than the carrier power. Where would this come from. except by sacrificing some of the sunlight that the satellite would be modulating. An LCD modulator would need to cover the whole area of the satellite collector / reflectorSamson4 said:The uplink could be amplified on the panel. It would be amplified again while modulating solar energy.
Yes, orbiting LCDs (liquid crystal displays) have the potential to replace radio towers for communication purposes. These displays can transmit information using light waves, similar to radio waves used by traditional towers.
Orbiting LCDs use photovoltaic cells to convert light signals into electrical signals. These signals are then transmitted to receivers on the ground, allowing for communication between the orbiting LCD and the receiver.
Yes, there are several potential benefits to using orbiting LCDs for communication. These include increased bandwidth, faster data transfer speeds, and less interference compared to traditional radio towers.
One limitation is the need for a clear line of sight between the orbiting LCD and the receiver on the ground. Additionally, orbiting LCDs may be more costly to implement and maintain compared to radio towers.
While there have been successful demonstrations of using orbiting LCDs for communication, it is not yet widely used. Further research and development is needed to make this technology a viable alternative to radio towers.