NASA sends Mona Lisa into space by LASER NASA has fired a greyscale image of the Mona Lisa to its Lunar Reconnaissance Orbiter, as part of an experiment using optics instead of radio for deep-space communications. Any space-watcher knows the frustration at the delays imposed by skinny radio channels in anything involving a deep-space mission. NASA is intensely …
This post has been deleted by its author
Depends who you ask. Wikipedia (yes, I know) for example defines Radio as "...the wireless transmission of signals through free space by electromagnetic radiation..." - which would include lasers - but then adds "...of a frequency significantly below that of visible light, in the radio frequency range, from about 30 kHz to 300 GHz." - which takes lasers out of the context.
And just to confuse things further, here's another extract from Wikipedia: "The prefix radio- in the sense of wireless transmission, was first recorded in the word radioconductor, a description provided by the French physicist Édouard Branly in 1897. It is based on the verb to radiate (in Latin "radius" means "spoke of a wheel, beam of light, ray")."
Personally, I think laser transmission is a radio transmission under the technical definitions. Under the *popular* definition (i.e., to people who listen(ed) to radios), it isn't. <sigh>
This post has been deleted by its author
This post has been deleted by its author
"Reed-Solomon coding was used to overcome interference caused by atmospheric turbulence."
Of the total errors, what proportion were caused by atmospheric turbulence? I'm wondering how well this method would perform if the laser communication was through the 'vacuum' of space over the entire path. Also, I assume that modifying a ranging laser is not the most effective way to give high speed data transmission.
In the future, I can imagine a high orbit laser being used for the 'space' part of the link with a broadband radio downlink to earth. The narrow beam spread of a laser would give much better energy density on the target but would make steering and pointing more difficult.
"The narrow beam spread of a laser would give much better energy density on the target but would make steering and pointing more difficult."
It's a subject JPL have given much thought to.
I think the phrase "nanorad pointing" will give some idea of their work.
You're right a lot of the errors are likely to be in the last 100km or so as all that air turbulence leads to the beam "wobbling" about. Adaptive optics or serious post reception processing are probably involved.
After 'Rick Rolling' are we going to get
La Gioconda Giffing.
Z$$77$777IIIIIII??7O8ZI??++++++++=====++
$$$$77IIIIIII?I?MODNNMMDM+++=+=========+
7777IIII??II?+ODI++I8NMNNMZ=~====~~=~===
$77IIIII???++?Z+~~~=?$DNMMM+==~~:~~::~==
77$I??+??+?+ID7+===+?I$8NMMNI??===~~:~=+
8ZO$777?+===ONI++=+7?I$8MMNMO$?I++=~:,=+
888OOO8ZZ=??DM87O=O+OZ?ZNMMMZZ$$$7+::~+?
D8OD8D8DD8OZNM?=+=I==+$8MMMN$7I7I7I+++?I
NDNN88888DDMNMZ?I7O=?7ONMMMMDDOOZZZ$77$O
NNNNDNDDDDNNMNNIZ$OO?78NMMMMNOOOZO$$77OO
MNNNNNDDDDDDMMMMI+?7Z8DNMMMMNOOZ$OZZZZZZ
MNMDDNNND8O$NMMMMDDDDNNNMMMMN88OZO8OOOZ$
MMNNNN88OZZZNMMMMM7ONDOODNMNMDOZOZOZZ$Z8
NNND8NDNZOOONMMMMMZI7$7I$NNNMMNDDZD$II7Z
NNNDDNDDNMNMMMMM$?+?+++?IDDDNNNDZI?I$$Z8
NNNDD8DDNNNMMM8?+==+=~=+78DNMNDDNOZ$7Z$$
MNMD$ZZDDNMMMZ7========+78DO$$$8NNM8O$$$
NDNNDD8O8MMMDI====~~~~=+$O$7DNNMMMMM8DD8
DDDOOZODMMMM88OI?~~~~=+$OMNNMMMMMMMNNOZ8
DD8888MMMMMNDNDDOOO8888NNMMNDNMMMMMMNNDD
MNDDD8MMMMMMMNMD88NNDDMMMMNNNDODDNMMNNZO
MD888NMMMMMMMMMNMMMMMMMMMMMMN88DNMMMNMND
D8OOONMMMMMMMMMMMMMMMMMMMMMNNDNMMMMMNNM8
MMNMMMMMMMMMMMMMMMMMMMMMMMMNNMMMMMMMNNNN
MMMMMMMNNMMMMMMMMNMMMMMMMMMMMMMMMMMMMMNN
MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMNMMMMMMN
MMMMNDMN8MMMMMMMMMMMMMMMMMMMMMMMMNMNNNNN
MMMMNDMDD8N$7$DMMMMMMMMMMMMMMMMMMMMNNNNM
MMMMNMNNN8$7777$$$NMMMMMMMMMMMMMMMMNNMNN
NMMMMMMMMN8OZ$77777$ODMMMNNDNMMNMMMNNNMN
NMMMMMMMMMNM8ZZ$Z$ZD$$DDOD8D8NNNMMMNNNNN
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2024
