Welcome to Laser Pointer Forums! If you are looking for a laser you may want to check out the database of laser pointer companies. The link will open in a new window for your convenience.

 Laser Pointer Forums - Discuss Laser Pointers Laser beam of 30km? Laser Pointer Company Database     Laser Top Sites List     Lasers by Type     Green Lasers

03-09-2011, 09:12 AM #1
 Junior Member Join Date: Mar 2011 Posts: 16 Rep Power: 0
andreicramp
Junior Member

Join Date: Mar 2011
Posts: 16
Rep Power: 0
Laser beam of 30km?

Hello,
I just created my account here. I work at a TV&Radio company and I install antennas. I want a gree/red/blue laser, doesn't really matter that can "connect" two antennas. The range of the beam should be seen for about 30km(19miles). Does something like this exist?

Thank you.
also, before you reply, I searched the entire forums and did not find anything that answers my question, so please stick to the topic.thanks

03-09-2011, 09:18 AM #2
 Junior Member Join Date: Mar 2011 Posts: 16 Rep Power: 0
andreicramp
Junior Member

Join Date: Mar 2011
Posts: 16
Rep Power: 0
Re: Laser beam of 30km?

here's a image describing what am i looking for.
Attached Thumbnails

Last edited by andreicramp; 03-09-2011 at 09:20 AM.

03-09-2011, 10:14 AM #3
 Class 3R Laser Join Date: Nov 2010 Location: Portugal Posts: 2,472 Rep Power: 62
anselm
Class 3R Laser

Join Date: Nov 2010
Location: Portugal
Posts: 2,472
Rep Power: 62
Re: Laser beam of 30km?

Hello and welcome to the forum!

First of all:
laser beams diverge, meaning they "grow" over distance.
How much depends on the optics used to shape the beam.
There's an inverse relationship between beam diameter and divergence.
You need a very low divergence, so you'd need a relatively large beam diameter to begin with.

gausian beam rev 2.0.xls
Laser Pointer Divergence Calculator

Typically, laser pointers have a divergence of 0.5~2mrad.

As you can see, getting a "spot" that is not the size of a football field after 30 000 meters

Second:
I imagine it to be very hard to accurately hit a target 30 000 meters away, and the wind
swaying the antenna would throw the laser off target all the time....
__________________
I'm away from home and lasers until late July!
Kryton Groove switch workaround
Get your warning label stickers 0.90\$ or less, depending on qty
The INDEX to the LPF
Beware! Scams a-plenty, don't be a sucker!
___________________________
ATTENTION
This forum is fullfilled mit special electronische equippment. Fingergrabbing and pressing the cnoeppkes from the lasers is
allowed for die experts only! So all the “lefthanders” stay away and do not disturben the brainstorming von here working
intelligencies. Otherwise you will be out thrown and kicked anderswhere! Also: please keep still and only watchen astaunished the blinkenlights.

03-09-2011, 11:08 AM #4
 Class 2M Laser Join Date: Jun 2010 Location: Sydney, AU Posts: 895 Rep Power: 96
goninanbl00d
Class 2M Laser

Join Date: Jun 2010
Location: Sydney, AU
Posts: 895
Rep Power: 96
Re: Laser beam of 30km?

A beam expander can help reduce this divergence; Laserglow markets their Hercules series of green portables for this purpose.

Laserglow Technologies - Handheld Lasers, Alignment Lasers and Lab / OEM Lasers

Even then, over 30km, the beam will have diverged massive amounts, even with a beam expander. You may want to talk to the engineers at Laserglow, they may be able to come up with something for you.

Here's the links to their products:

Laserglow Technologies - Handheld Lasers, Alignment Lasers and Lab / OEM Lasers

Laserglow Technologies - Handheld Lasers, Alignment Lasers and Lab / OEM Lasers

03-09-2011, 02:50 PM #5
 Class 2M Laser Join Date: May 2010 Location: ohio Posts: 530 Rep Power: 23
Class 2M Laser

Join Date: May 2010
Location: ohio
Posts: 530
Rep Power: 23
Re: Laser beam of 30km?

It looks to me like you are trying to send and recieve information. Like the fellow above said, even if you overcome the problems of wind and divergence, you will need a laser that can be modulated. That would require a labstyle laser.
__________________
635nm 800mw in a Cree C3 w/mosquito thanks RHD
635nm 300mw labby

600mw JetL PL-C 880mw Peak Thanks Hak and Gray
445nm 1550mw Wolf800 Thanks Flaminpyro
405nm 600mw in a Cree C3 Thanks Daguin
Plus a handful of miscellaneous cheapy handhelds

03-09-2011, 08:40 PM #6
 Class 4 Laser Join Date: Sep 2007 Location: Wisconsin Posts: 8,854 Rep Power: 1363
Cyparagon
Class 4 Laser

Join Date: Sep 2007
Location: Wisconsin
Posts: 8,854
Rep Power: 1363
Re: Laser beam of 30km?

Forgive me if this is a dumb question, mister cramp, but:

Why?
__________________
A problem well stated is a problem half solved.

03-09-2011, 08:48 PM #7
 Junior Member Join Date: Mar 2011 Posts: 16 Rep Power: 0
andreicramp
Junior Member

Join Date: Mar 2011
Posts: 16
Rep Power: 0
Re: Laser beam of 30km?

Thank you all for taking the time to reply.

@Cyparagon ;I need to show my clients that there are no obstacles(trees buildings etc ) between the 2 antennas.

03-09-2011, 09:08 PM #8
 Class 3R Laser Join Date: Nov 2010 Location: Portugal Posts: 2,472 Rep Power: 62
anselm
Class 3R Laser

Join Date: Nov 2010
Location: Portugal
Posts: 2,472
Rep Power: 62
Re: Laser beam of 30km?

just get some binoculars instead then.
__________________
I'm away from home and lasers until late July!
Kryton Groove switch workaround
Get your warning label stickers 0.90\$ or less, depending on qty
The INDEX to the LPF
Beware! Scams a-plenty, don't be a sucker!
___________________________
ATTENTION
This forum is fullfilled mit special electronische equippment. Fingergrabbing and pressing the cnoeppkes from the lasers is
allowed for die experts only! So all the “lefthanders” stay away and do not disturben the brainstorming von here working
intelligencies. Otherwise you will be out thrown and kicked anderswhere! Also: please keep still and only watchen astaunished the blinkenlights.

03-10-2011, 12:45 AM #9
 Class 4 Laser Join Date: Sep 2007 Location: Wisconsin Posts: 8,854 Rep Power: 1363
Cyparagon
Class 4 Laser

Join Date: Sep 2007
Location: Wisconsin
Posts: 8,854
Rep Power: 1363
Re: Laser beam of 30km?

Take a picture of one antenna from the top of the other. If there is a clear line of sight, then there are no obstacles. No complicated laser equipment needed.
__________________
A problem well stated is a problem half solved.

03-11-2011, 01:51 AM #10
 Class 1M Laser Join Date: Oct 2010 Location: Austin, TX Posts: 151 Rep Power: 18
sampson
Class 1M Laser

Join Date: Oct 2010
Location: Austin, TX
Posts: 151
Rep Power: 18
Re: Laser beam of 30km?

Quote:
 Originally Posted by andreicramp I need to show my clients that there are no obstacles(trees buildings etc ) between the 2 antennas.
This is not practical.
__________________
5x ~50mw 405nm Violet Pointers (ItemQuickShip)
1x <1000mw 445nm Blue Arctic S3
2x >50mw 532nm Green Super Beast 006 (ItemQuickShip)
1x >50mw 532nm Green Super Beast 005 (ItemQuickShip)
1x >50mw 532nm Green Pen (ItemQuickShip)
1x <150mw 532nm Green 2009 WL E2
1x ~10mw 633nm HeNe NEC Head
1x ~10mw 633nm HeNe Xerox Head
1x >100mw 650nm Red Lab Unit
1x >200mw 650nm Red Lab Unit
1x <80mw 780nm NIR Handheld

04-12-2011, 11:01 PM #11
 Class 1 Laser Join Date: Nov 2010 Location: Rolla, Mo Posts: 85 Rep Power: 10
rvrh3
Class 1 Laser

Join Date: Nov 2010
Location: Rolla, Mo
Posts: 85
Rep Power: 10
Re: Laser beam of 30km?

...and at 30 meters high, the horizon is only 19.55 miles away from the tower.
__________________
<200mW 532nm Wicked Lasers E3 worth the wait

04-12-2011, 11:48 PM #12
 Class 1M Laser Join Date: Apr 2011 Posts: 107 Rep Power: 6
2100
Class 1M Laser

Join Date: Apr 2011
Posts: 107
Rep Power: 6
Re: Laser beam of 30km?

Quote:
 Originally Posted by rvrh3 ...and at 30 meters high, the horizon is only 19.55 miles away from the tower.
Hi,

VHF/UHF Line of Sight Calculator

Total radio horizon is 28 miles, or 46km.

To the original poster. It'd be mighty difficult to aim. I'd suggest just get on top of of 30m for both places, get one of those 5W UHF transceivers. If its really line of sight you should be able to get reception to each other. And a mobile phone as comms of course. To further confirm I think a high powered greenie or a 1.5W 445nm custom job with focusable lens at Buy Sell & trade here should work.

You can just rely on pure sight, but since you mentioned clients you may wisht to record it down on a videocam, nowadays an affordable 2nd hand D90 with a 50 or 85mm f1.8 lens would be able to see slightly better than a human eye. The green/blue flash from the laser should be enough proof.

You'd need the divergence. I have targets which ranges from 21km all the way to the visual horizon (51km away) here. It is not easy to aim with wind and tripod movement factored in. Handheld would mean there is a chance of the other side seeing flashes of the laser, better for "confirmation".

9km
YouTube - 1 watt Blue Laser at 9 Kilometres Range

The video looks very dark. A normal dSLR with cheap 50 f1.8 or 85mm f1.8 lens would make it look much brighter than the eyes can see.

YouTube - Canon 550D + Sigma 30 mm f1.4 @ Night

Hope my idea helps.

04-13-2011, 01:00 AM #13
 Class 4 Laser Join Date: May 2009 Location: West central Oregon Posts: 5,448 Rep Power: 748
Flaminpyro
Class 4 Laser

Join Date: May 2009
Location: West central Oregon
Posts: 5,448
Rep Power: 748
Re: Laser beam of 30km?

I would have to agree with Cyparagon what you need is a video camera
and take pictures of one antenna while your on top of the other one
that should prove to your client there are no trees growing 90' high in the way.
And then come back here and show us the video

Welcome to the forum
__________________
White Fusion Time Machine 445
473nm LRS-0473-KFM-00150-10 158.5mW Lab style
laser used in the making of the latest TRON movie

CNI PGL-III-C-589 125mW
520 in a SH-032
Viasho 532nm 500mW
CNI pen 532nm 84mW
The Violet Pip Squeek 45mW

_____________________________________
LOOKING FOR A HOST WITH PERFECT HEAT SINKING
order your C-88 Cu kit today !

Last edited by Flaminpyro; 04-13-2011 at 01:03 AM.

04-13-2011, 01:04 AM #14
 Class 2M Laser Join Date: Apr 2011 Location: Clearwater, Florida Posts: 917 Rep Power: 48
Haloid95
Class 2M Laser

Join Date: Apr 2011
Location: Clearwater, Florida
Posts: 917
Rep Power: 48
Re: Laser beam of 30km?

A 50mw-80mw laser (green) should do the trick, and welcome to the forum.

04-13-2011, 05:16 AM #15
 Class 1 Laser Join Date: Nov 2010 Location: Rolla, Mo Posts: 85 Rep Power: 10
rvrh3
Class 1 Laser

Join Date: Nov 2010
Location: Rolla, Mo
Posts: 85
Rep Power: 10
Re: Laser beam of 30km?

Quote:
 Originally Posted by 2100 Hi, VHF/UHF Line of Sight Calculator Total radio horizon is 28 miles, or 46km.
I stand corrected. Thank you.
__________________
<200mW 532nm Wicked Lasers E3 worth the wait

04-13-2011, 06:57 AM #16
 Class 1M Laser Join Date: Apr 2011 Posts: 107 Rep Power: 6
2100
Class 1M Laser

Join Date: Apr 2011
Posts: 107
Rep Power: 6
Re: Laser beam of 30km?

Quote:
 Originally Posted by Flaminpyro I would have to agree with Cyparagon what you need is a video camera and take pictures of one antenna while your on top of the other one that should prove to your client there are no trees growing 90' high in the way.
I can see a couple of antennas of my neighbouring country (Indonesia). Even at 21-25km it is very difficult to see a big 200m tall type of steel mast (self supporting pyramid type - no guy wire). I can see the red warning lights reasonably clear at night against a black sky background.

Last edited by 2100; 04-13-2011 at 07:03 AM.

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

All times are GMT. The time now is 08:31 AM.

 -- DarkShadows V5 -- Responsive LPF -2562016 -- Default Style Contact Us - Laser Pointer Forums - Archive - Top