Here's a requirement for the manned "rocketship".
Any good practical solutions that properly fit he spec.
Read right through before replying - he already know about cheaper doppler
radars.
Adequate solutions need to be both cost effective and effective.


regards



      Russell McMahon
_____________________________


----- Original Message -----
Subject: [AR] rader/laser altimeters


> I am about to dump a pretty significant amount of money on a rangefinder
so
> that we can get our vehicles auto-hovering and auto-landing.  If anyone
can
> offer me any better directions, I would appreciate it.
>
> The best solution I have found so far is this, quoted at $7500:
>
> www.armadilloaerospace.com/misc/oconner_altimeter.jpg
>
> The next best is this at $6500 (plus filing for an export license from
> England):
>
> www.armadilloaerspace.com/misc/roke_altimeter.jpg
>
> This laser unit is cheaper at $3500, but I'm not sure if the communication
> rate is good enough to average enough samples for deriving accurate
> velocity, and it may not work well over fields:
>
> http://www.laseroptronix.com/flyg/altm400.html
>
>
> The criteria I have is:
>
> High update rate.  10hz is bare minimum.  Ideally rs232, but analog is ok.
>
> Accurate enough to derive vertical velocity at those rates without
> excessive noise.
>
> At a minimum, accurate range from 5' to 100' or so.
>
> No interference with 2.4ghz communication equipment.
>
> Small and low power are a plus.
>
>
> A high update rate GPS solution would probably work, but the 20hz gps
> systems were $15k+ last time I checked.
>
> I could probably make our intertial system accurate enough for our 15
> second parking lot flights, but we are looking towards higher altitude
> flights with long coast periods, and inertial systems good enough for that
> are real expensive.  I really like direct measurement where possible,
> rather than integrating continuously, anyway.
>
> There are a lot of relatively cheap ($1500 or so) doppler radar speed
> sensors available, but they only give the absolute value of speed, and
also
> pick up horizontal motion, so they won't work for hovering and landing.
>

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