Hand-held radar

[sarabande]

Right, you super techies !

Why can't we have a radar "gun" which is analagous to a powerful torch ? Point or sweep the gun in the direction where you think some vessel or headland is creeping up on you, and a return is plotted on the screen showing distance off, etc.

I appreciate there may be issues with emissions, but as a cheap alternative to a frantically rotating scanner, a hand held gun, even with a range of -say - 4 or 5 miles would be a useful device.

 

[fireball]

Directional Stability ....

 

[kingfisher]

AH, but doesn't that negate the whole purpose of radar: you will only use the gun if you already know/suspect that something is out there. If you know/suspect that something is out there, the only info that is missing is its speed and course.

 

[Bergman]

You would need some big muscles to support the batteries.

 

[Guest]

You mean use this sort of technology:

http://www.roke.co.uk/mra/

Stabilization is not too hard since my satellite dish holds the patch antenna in line with a geostationary satellite to an accuracy less than my radars beam width.

 

[sarabande]

I was thinking of something about the size of a loud hailer. I take the point of only using it when you think that something is there, but as an example, when you can hear a big vessel approaching in fog, but can't see it, a gun would give range and direction.

 

[bendyone]

Police speed gun??

 

[fireball]

Will it automatically issue speeding tickets?

 

[Dyflin]

[ QUOTE ]
Will it automatically issue speeding tickets?

[/ QUOTE ]

More importantly, where can I buy into the franchise?! /forums/images/graemlins/tongue.gif

 

[Guest]

Post deleted by danfoley

 

[Danny]

[ QUOTE ]
Not exactly handheld but that seems to me to be what the well established but not very popular CARD system does?

[/ QUOTE ]Except it won't give the range - only the bearing.

 

[dulcibella]

Good idea - you can also threaten your crew with a dose of microwaves in the nuts if they get mutinous.

 

[Bergman]

Not sure that I would have the nerve to wait until I hear the super tankerbefore looking for it on radar - especially if I am sitting in the wheel house.

Don't know what such a device would be likely to cost, but since you can buy a conventional low power radio for about £6/700 which gives a substantially greater level of protection I guess you would have to be looking at around £2/300 to make it financially viable, probably less, and I'm not sure you can do it for that much.

As an after thought - what about a directional microphone with a high gain low noise amplifier scanning a low band of frequencies listening for the sounds of a diesel engine. Much lower power consumption. Won't give range but will find a constant bearing to show collision risk.

 

[Danny]

[ QUOTE ]
what about a directional microphone with a high gain low noise amplifier scanning a low band of frequencies listening for the sounds of a diesel engine.

[/ QUOTE ]How about sonar? Listen for the prop noise.

"Dive, dive, dive. Ready tubes one and two..."

 

[roly_voya]

The simple answer is in 'I appreciate there are issues with emmissions' Normal small ship radars have an output of 2-4KW in the microwave band hence it is recomended the a permenantly installed such that no person will be directly exposed to the beam. I believe (but not sure) that the safe distance is about 6ft. So either it will be highly dangerouse or so low power it will be useless in poor conditions such as fog... Nice try though

 

[DaveS]

[ QUOTE ]
what about a directional microphone with a high gain low noise amplifier scanning a low band of frequencies listening for the sounds of a diesel engine. Much lower power consumption. Won't give range but will find a constant bearing to show collision risk.

[/ QUOTE ]

You've just reinvented an 80 year old technology! Look up "sound mirrors" for some really interesting stuff. (It was superseded in the 1940s by RADAR...)

 

[Guest]

There is no real need for kW outputs from radar anymore. The problem is finding your pulse return out of all the other noise. Once you start using intelligent pulses from solid state oscillators then the power comes right down as the detection can be made much much better.

How about just infrared:
http://www.austinfrared.com.au/documents.asp?ID=23&PID=7

Try this sales film targeted at your boating needs. Unknown price!

http://www.flir.com/imaging/nmc/media/streaming/08a8b040-ae4c-405c-88c1-eb66c9e30b9a.asx


There is also a lot of research on parasitic/passive radars. That is using the pulses transmitted from other peoples radar and "see" the bounces off your targets. The maths looks hard!

There are also a lot of LIDAR work going on with high power lasers (Now good lasers are solid state) and detecting the return. Very like laser guided bomb technology.

http://www.lasermap.com/laserM/en/products.htm