CrashPro

My Feedback: (1)

Could one of you Doppler wizards please see if you can get a speed reading on this P40 flying by?......there is engine noise in the background from a control line plane on the ground a couple hundred feet behind me (as the P40 aproaches me)...hope it doesn't interfere with a good reading.

Thanks to anyone that can get a reading on this. http://www.cvrcclubvideos.us/P40Flyby.wmv


George

still4given

You don't list the temperature but I got 119mph at 70 deg F.

CrashPro

My Feedback: (1)

Wow...is it really that fast?...
hmmm...that video was taken between 9 and 10am yesterday..... and today's weather forecast is the same as yesterdays.....about 61 degrees at 9am....71 degrees by 10am.....so your reading should be pretty darn close.

Dang....I know that thing really looks fast flying by.....but I would have 'guessed' it about 90-100mph.

Thankyou very much still4given

Mike Connor

My Feedback: (5)

My lines were not real clean but two recording attempts gave me speeds just over 100 mph to 103 mph. We are usually a lot closer then that.

still4given

Here is what I see.

Mike Connor

My Feedback: (5)

I am using WaveOScope and keep coming up with the same thing. Could you try my sound file in your software?
http://www.mikesrc.us/p40.wav

still4given

Hi Mike,

With your file I get between 97MPH and 101MPH. Your file is shorter than mine. I think the extra duration shows a higher and lower line. Try recording the entire file.

Blessings

CrashPro

My Feedback: (1)

Hi guys

Next time Serge flies the plane, (probably Sunday)...I will get several passes on video.

I downloaded that program one time,..but it was in German,...and I couldn't figure out how to use it.
Do you have a link to an English version?.....and....does it have instructions how to use it?

Thanks

George

Mike Connor

My Feedback: (5)

Using the entire file I did come up with #'s similar to yours. I intentionally left the dive off mine for level flight speed only.
WaveOScope web site. I can right click on the page and go to "page info" to translate the page to english.
http://www.sprut.de/electronic/soft/scope.htm
If that does not work, this site should be able to translate it for you.
http://babelfish.yahoo.com/translate_txt

CrashPro

My Feedback: (1)

Thanks Mike......I'll see if I can figure it out.

still4given

When I listen to the video, I really can't hear the engine much during the dive so I didn't give it much weight. I'm sure the speed of the plane was affected by starting with a dive but don't we all do that?

Crash, if you can't get waveosscope to work for you let me know and I will try to talk you through the system I use.

Blessings, Terry

CrashPro

My Feedback: (1)

Thanks Terry......I'm sure you'll be hearing from me.....

CrashPro

My Feedback: (1)

Haven't had time to try to figure out how to use that waveoscope program....here is [link=http://www.cvrcclubvideos.us/FlyBys.wmv]2 more passes[/link]

Temperature was about 60 degrees F at the time.

Mike Connor

My Feedback: (5)

I got about 112 mph on the first pass. I will let you do the second pass.

CrashPro

My Feedback: (1)

Cool....112mph........thanks Mike

still4given

Hmmm, I get 119.3mph on the first pass and 129mph on the second pass.


In WaveOsOscope I get 196 km/h on the first pass and 214 km/h in the second pass.

Blessings, Terry

Mike Connor

My Feedback: (5)

I re-checked my #'s and came up with the same thing for both passes, a little over 110 mph. My recordings are short and only include the level flight part of the passes. Was there any wind?

CrashPro

My Feedback: (1)

As I recall Mike,...there was just a slight cross wind at the time....2-3mph... Thanks for doing this guys......very interesting,..

George

still4given

I'm not sure how you know when the level flight begins. When I look at the wave file, I look for a flat spot on each end to do my measurement. I'm sure that the mic being off to the side of the flight path takes away from the accuracy as well. Ideally, the plane would fly directly at the mic and directly away. That way the curve in the center would be very short instead of a long slide.

Mike Connor

My Feedback: (5)

I use Window's sound recorder to record a new file while I watch the video. I like a second or two coming towards the mic and a second or tow leaving the mic. I make sure there are no turns or dives while I record.

still4given

That is basically how I do it but because of the distance out to the plane, sometimes 2 seconds is not enough. The closer the plane gets to center. the lower the frequency. It is not like when the plane flies right over the mic. Then you would have a stark difference. I agree, any turns throw it off as well.

Blessings, Terry