Software Defined Radar Altimeter
Andrew Barton
We need to find a cheap option for the landing radar otherwise the big
aerospace primes and the space agencies will try to exploit this
weakness in our team.
On that note, I would like to share another crazy idea with you...
Is it possible to make such electronics out of the same board/s that
would be used for a software defined radio? Our Partner at the Wroclaw
University in Poland has a lab for testing radio systems, and he's got
experience making space-qualified antennas so all we need is the
electroincs.
Are you interested in making the electronics for a radar altimeter?
I'm thinking of something of similar specs to what was done for the
Moon Impact Probe (MIP) which the indians recently crashed into the
Moon.
The 'Files' page includes a basic technical description of the
Indian's altimeter design. You'll see that it has a range of about
5km, which is enough for the terminal altimetry of our lander. Lateral
velocity can be measured using a camera with optical flow algorithms,
of course correcting for rotation rates using the lander's attitude
control sensors.
Cheers
AB
Marco Ostini
I'd like to explore options of what we can assist with regarding a
landing radar. Certainly we'd like to jump in and assist where ever we
can.
The Build team are due a brainstorming session so I'll do some
homework and see where we arrive at.
> On that note, I would like to share another crazy idea with you...
I love crazy ideas, that's how so much innovation comes about.
Cheers,
Marco
MarcoOstini
> We need to find a cheap option for the landing radar otherwise the big
> aerospace primes and the space agencies will try to exploit this
> weakness in our team.
frequency modulated) radar and considers it "*very* doable". We're
investigating this further, and we'll be in contact when we have
specifics.
> Our Partner at the Wroclaw
> University in Poland has a lab for testing radio systems, and he's got
> experience making space-qualified antennas so all we need is the
> electroincs.
Cheers,
Marco
Andrew Barton
> frequency modulated) radar and considers it "*very* doable". We're
> investigating this further, and we'll be in contact when we have
> specifics.
AB
Andrew Barton
AOES has just hired a new intern who will spend the next 2.5 months
working on lunar mission technologies under my supervision. I
discussed with her today the idea of a CWFM SDR for the altimeter
function and she is very interested to get involved, first starting
with some literature research, and then perhaps later with hardware
specification and/or analysis.
Her name is Pooja Mahapatra. I have placed a copy of her CV on the
Files page.
This is her email address:
pooj....@gmail.com
Could you please send her any information or thoughts you have so
far?
Marco, would it be appropriate to add her to this mailing list?
Cheers
AB
Lee Begg
I have started some documentation on the wiki about the SDRA. It is here:
http://www.lunarnumbat.org/cgi-bin/twiki/view/LunarNumbat/LNTaskRadarAltimeter
I will upload a couple of diagrams shortly, to help illustrate how it works.
There are a few webpages that document how CWFM radar works on the web, but
for a highly technical reference, I briefly borrowed "Design of
Multi-frequency CW Radars" by Mohinder Jankirama from my Uni library, and
found it was a good reference, but it quickly descended into math I didn't
have time to figure out.
In general terms, CWFM radar is very clever and simple. Send out linear up and
down frequency sweeps, mix it with the return signal, low pass the result,
sample the result, feed each sweep (one set for up, one for down) into FFT.
Then average the results of two FFTs to get the range, difference the results
to get the speed.
Hope this help. Feel free to contact me for more, and keep an eye on the wiki
page as I update it.
Regards
Lee Begg
Marco Ostini
Your work on the Radar Altimeter is very valuable and important.
Please do continue to document your work on the LN wiki.
Cheers,
Marco
2009/7/23 Lee Begg <ll...@paradise.net.nz>:
Andrew Barton
free on one of these balloon flights by the Austrian Space Forum. I
have asked if they could fly it, I'll let you know the answer soon.
http://www.polares.org/cms/aid=721.phtml
After the balloon bursts (at ~32km) the descent phase is breaked by a
drogue parachute, and it looks like a perfect test of a descent
towards the lunar surface!
On Jul 23, 3:09 pm, Marco Ostini <marco.ost...@gmail.com> wrote:
> Thanks Lee,
>
> Your work on the Radar Altimeter is very valuable and important.
> Please do continue to document your work on the LN wiki.
>
> Cheers,
> Marco
>
>
>
> > Sorry about the delay in replying, I have been very busy lately.
>
> > I have started some documentation on the wiki about the SDRA. It is here:
Lee Begg
> If we manage to make a radar altimeter, we might be able to fly it for
> free on one of these balloon flights by the Austrian Space Forum. I
> have asked if they could fly it, I'll let you know the answer soon.
>
> http://www.polares.org/cms/aid=721.phtml
>
> After the balloon bursts (at ~32km) the descent phase is breaked by a
> drogue parachute, and it looks like a perfect test of a descent
> towards the lunar surface!
Sounds like an ideal way to test it easily. The video is impressive.
Regards
Lee Begg