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Optical_DX · Australian Optical DX Group
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Group Information

  • Members: 85
  • Category: Hobbies
  • Founded: Nov 7, 2005
  • Language: English
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Activity within 7 days:

6 New Messages - New Questions

Description

This group is for those interested in long distance optical communication.

In July 2005, at the GippsTech conference, Chris Long gave a presentation on long distance optical communications and his efforts in setting a new world record for voice communication using non-coherent light. This presentation was repeated to a number of groups and has stirred up a lot of interest in optical communications.

As a result, this group has been set up to enable discussion of optics, electronics, construction and operation of long distance optical systems.

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Re: Re : [Optical_DX] Green laser for laser range finder. Spread spe
Hi. OK I understand what you mean when I see the graph. The near IR reflectance for dense grass is approx 5 times higher than for the visual range. That
Posted - Mon Jul 13, 2009 9:52 pm
 lb3hc
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Re : [Optical_DX] Green laser for laser range finder. Spread spectru
Have a look on the grass spectrum and compare the green reflectance with the near IR one... http://www.aai.ee/bgf/ger2600/d_grass.png 73 Yves F1AVY
Posted - Mon Jul 13, 2009 10:31 am
 Garnier Yves
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Green laser for laser range finder. Spread spectrum modulation
To continue on the range finder discussion: What about using a green laser pointer? It will give better reflection from the clorofyl of the green vegetation.
Posted - Mon Jul 13, 2009 9:30 am
 lb3hc
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BTW
FYI: http://www.guardian.co.uk/technology/2009/jun/21/mcdonald-observatory-space-laser-funding Tom
Posted - Fri Jul 10, 2009 5:45 pm
 Tom Becker
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Re: Re : [Optical_DX] Laser range finder. 25 Mhz modulation, sensiti
... No, I haven't needed to get into really low-light detection yet. Gated single-photon ranging is beyond my goals for now. My targets yield relatively
Posted - Wed Jul 8, 2009 4:14 pm
 Tom Becker
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Message History

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2009 5 3 1 22
2008 3 16 2 1 3 1 9 44 42
2007 20 6 22 13 10 12 11 10 4 20 4
2006 31 17 10 28 9 4 2 3 2 3 5
2005 10 9
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