Dopler wave o scope use
10-27-2008, 12:18 PM
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Dopler wave o scope use
I can load in a file and postion the green and red line but don't know what I'm doing. Not very good at german.
Where am I ment to put these two lines? It seems if they are further apart the speed is increased or not acurate.
Any advise please
Where am I ment to put these two lines? It seems if they are further apart the speed is increased or not acurate.
Any advise please
10-27-2008, 06:14 PM
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RE: Dopler wave o scope use
Find one line that is well defined on the left and right side and place your lines like on the picture below.
If you have Google tool bar just right click on the page and go to page info. You then can translate the page to English. If not try the site below.
http://babelfish.yahoo.com/translate_txt
If you have Google tool bar just right click on the page and go to page info. You then can translate the page to English. If not try the site below.
http://babelfish.yahoo.com/translate_txt
10-27-2008, 06:34 PM
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RE: Dopler wave o scope use
Ok thanks Mike,
Other than a well defined line, how do you know which line to choose. The lines are wider along the graph??
The additional instructions are in a pdf file so unsure how to convert that to english translation.
Other than a well defined line, how do you know which line to choose. The lines are wider along the graph??
The additional instructions are in a pdf file so unsure how to convert that to english translation.
10-27-2008, 06:56 PM
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RE: Dopler wave o scope use
Don't know if it's the latest version, but waveOscope has been translated into english.
Look here: [link=http://happykillmore.com/main_downloads.asp]Happy Killmore's translation[/link]
Look here: [link=http://happykillmore.com/main_downloads.asp]Happy Killmore's translation[/link]
.
10-27-2008, 07:28 PM
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RE: Dopler wave o scope use
Ok I think I got the hang of it. It appears that it doesn't matter which line you choose as long as its a good one. Even if you choose a line that is wider apart up the scale, as frequency increases so does same speed even if you had chosen a narrow line back down the scale.
10-27-2008, 07:37 PM
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RE: Dopler wave o scope use
ok thanks lee hop, i cant get the pdf file to open though.
I've just tried doing a jet and a 4 stroke without much luck. Are these two not possible to do?
I've just tried doing a jet and a 4 stroke without much luck. Are these two not possible to do?
10-27-2008, 08:07 PM
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RE: Dopler wave o scope use
Any plane that makes a constant noise can be dopplered. Electrics, glow, gas, 2st, 4st, even jets. The motor's noise is used almost like a clock pulse, giving a constant pitch noise that is shifted as the plane goes by.
You'll see several lines, all doing a big swooping dive as the plane goes by. The lines higher up the display seem to swoop more deeply. They all change by the same percentage, though, so they will all give the same speed. They are different octaves of the same motor noise. If you're also calculating for RPM, you then need to know which octave you're measuring from.
I don't use wave-o-scope, I use Spectrogram16 and an XL spreadsheet I found on the OTHER forum, that also returns RPM's. I didn't feel like messing with german translation on my speedy dial-up....
Just choose a single octave line, one that's clear and seems well defined. Measure the frequency just before and just after the plane passes (the top and bottom of the curve). Plug 'em into the spreadsheet, and out pops the speed.
Audio Doppler is very sensitive to how the pass is flown, too. If RPM's are falling thruought the pass, as in agressivly diving, pulling level and doing the pass, the speed output will be inflated, as the falling engine note on top of the doppler will exaggerate the effect. An engine that suffers a lean-stumble mid-pass will show the same effect. Passes flown closer to the microphone are easier to doppler, as the "slew" happens faster.
Google "model aircraft doppler speed analysis" First hit, jfinch's post, #8.
J
You'll see several lines, all doing a big swooping dive as the plane goes by. The lines higher up the display seem to swoop more deeply. They all change by the same percentage, though, so they will all give the same speed. They are different octaves of the same motor noise. If you're also calculating for RPM, you then need to know which octave you're measuring from.
I don't use wave-o-scope, I use Spectrogram16 and an XL spreadsheet I found on the OTHER forum, that also returns RPM's. I didn't feel like messing with german translation on my speedy dial-up....
Just choose a single octave line, one that's clear and seems well defined. Measure the frequency just before and just after the plane passes (the top and bottom of the curve). Plug 'em into the spreadsheet, and out pops the speed.
Audio Doppler is very sensitive to how the pass is flown, too. If RPM's are falling thruought the pass, as in agressivly diving, pulling level and doing the pass, the speed output will be inflated, as the falling engine note on top of the doppler will exaggerate the effect. An engine that suffers a lean-stumble mid-pass will show the same effect. Passes flown closer to the microphone are easier to doppler, as the "slew" happens faster.
Google "model aircraft doppler speed analysis" First hit, jfinch's post, #8.
J
10-27-2008, 08:26 PM
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RE: Dopler wave o scope use
ORIGINAL: mk1spitfire
It appears that it doesn't matter which line you choose as long as its a good one. Even if you choose a line that is wider apart up the scale, as frequency increases so does same speed even if you had chosen a narrow line back down the scale.
It appears that it doesn't matter which line you choose as long as its a good one. Even if you choose a line that is wider apart up the scale, as frequency increases so does same speed even if you had chosen a narrow line back down the scale.
This program and my hardware works well with two stroke engines. Some people don't but I have trouble with 4 stroke, DF and Jets.
10-28-2008, 05:34 AM
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RE: Dopler wave o scope use
Ok, cheers
Is there a way of saving the graph to file on wavescope?
Running a video an panning the plane might not give you a true speed???
Is there a way of saving the graph to file on wavescope?
Running a video an panning the plane might not give you a true speed???
10-28-2008, 07:42 AM
#12
RE: Dopler wave o scope use
ORIGINAL: Jburry
Any plane that makes a constant noise can be dopplered. Electrics, glow, gas, 2st, 4st, even jets. The motor's noise is used almost like a clock pulse, giving a constant pitch noise that is shifted as the plane goes by.
You'll see several lines, all doing a big swooping dive as the plane goes by. The lines higher up the display seem to swoop more deeply. They all change by the same percentage, though, so they will all give the same speed. They are different octaves of the same motor noise. If you're also calculating for RPM, you then need to know which octave you're measuring from.
I don't use wave-o-scope, I use Spectrogram16 and an XL spreadsheet I found on the OTHER forum, that also returns RPM's. I didn't feel like messing with german translation on my speedy dial-up....
Just choose a single octave line, one that's clear and seems well defined. Measure the frequency just before and just after the plane passes (the top and bottom of the curve). Plug 'em into the spreadsheet, and out pops the speed.
Audio Doppler is very sensitive to how the pass is flown, too. If RPM's are falling thruought the pass, as in agressivly diving, pulling level and doing the pass, the speed output will be inflated, as the falling engine note on top of the doppler will exaggerate the effect. An engine that suffers a lean-stumble mid-pass will show the same effect. Passes flown closer to the microphone are easier to doppler, as the "slew" happens faster.
Google "model aircraft doppler speed analysis" First hit, jfinch's post, #8.
J
Any plane that makes a constant noise can be dopplered. Electrics, glow, gas, 2st, 4st, even jets. The motor's noise is used almost like a clock pulse, giving a constant pitch noise that is shifted as the plane goes by.
You'll see several lines, all doing a big swooping dive as the plane goes by. The lines higher up the display seem to swoop more deeply. They all change by the same percentage, though, so they will all give the same speed. They are different octaves of the same motor noise. If you're also calculating for RPM, you then need to know which octave you're measuring from.
I don't use wave-o-scope, I use Spectrogram16 and an XL spreadsheet I found on the OTHER forum, that also returns RPM's. I didn't feel like messing with german translation on my speedy dial-up....
Just choose a single octave line, one that's clear and seems well defined. Measure the frequency just before and just after the plane passes (the top and bottom of the curve). Plug 'em into the spreadsheet, and out pops the speed.
Audio Doppler is very sensitive to how the pass is flown, too. If RPM's are falling thruought the pass, as in agressivly diving, pulling level and doing the pass, the speed output will be inflated, as the falling engine note on top of the doppler will exaggerate the effect. An engine that suffers a lean-stumble mid-pass will show the same effect. Passes flown closer to the microphone are easier to doppler, as the "slew" happens faster.
Google "model aircraft doppler speed analysis" First hit, jfinch's post, #8.
J
Can you tell me where I can find the spread sheet? I had it saved but now can't find it. I also use a different spectrum player because it reads 4 strokes better that Wave o scope. It is a little more work to have to use a separate spread sheet but at least it can read the 4 strokes. I couldn't get wave o scope to do it.
Thanks, Terry
10-28-2008, 07:56 AM
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RE: Dopler wave o scope use
10-28-2008, 09:40 AM
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RE: Dopler wave o scope use
ORIGINAL: mk1spitfire
Ok, cheers
Is there a way of saving the graph to file on wavescope?
Running a video an panning the plane might not give you a true speed???
Ok, cheers
Is there a way of saving the graph to file on wavescope?
Running a video an panning the plane might not give you a true speed???
Panning with the camera is not a problem. The microphone is one place and the plane should fly in a straight line in front of the camera. Two to four seconds is all you need.
Edit - Change Print Shop Pro to Paint Shop Pro.
10-28-2008, 10:10 AM
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RE: Dopler wave o scope use
cool, didn't know that about print screen.
i ve tried spectrogram 16 too now but just get a fuzz off graphics and no lines when trying to caputure 4 stroke sound passing.
Should the cursor be on the line or next to line?
i ve tried spectrogram 16 too now but just get a fuzz off graphics and no lines when trying to caputure 4 stroke sound passing.
Should the cursor be on the line or next to line?
10-28-2008, 10:20 AM
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RE: Dopler wave o scope use
Hmmm... It's possible that there's alot of background noise hiding the plane's sound.... I've never had a problem, so no help here...
I centre the cursor in the line, both coming and going. What's important is that you are consistant.
J
I centre the cursor in the line, both coming and going. What's important is that you are consistant.
J
10-28-2008, 10:40 AM
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RE: Dopler wave o scope use
umm, the sound is good. Just goblede gook on screen for this particular 4 stroke pass.
Also, working out rpm on spectrogram 16 spreadsheet. Is no 6 box allways the rpm?
Also, working out rpm on spectrogram 16 spreadsheet. Is no 6 box allways the rpm?
10-29-2008, 04:00 PM
#19
RE: Dopler wave o scope use
Can you attach the wave file here so I could try my Spectrum player and see if I can get a good reading?
I use this freeware
[link=http://www.visualizationsoftware.com/gram.html]Spectrogram Version 16[/link]
By Visualization Software LLC
It will play MP3 or Wave and I can see 4stroke files well enough to get the frequencies.
If you can attach the wave file I will see if I can dopler it for you.
Blessings, Terry
I use this freeware
[link=http://www.visualizationsoftware.com/gram.html]Spectrogram Version 16[/link]
By Visualization Software LLC
It will play MP3 or Wave and I can see 4stroke files well enough to get the frequencies.
If you can attach the wave file I will see if I can dopler it for you.
Blessings, Terry
10-30-2008, 07:10 AM
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RE: Dopler wave o scope use
I have tried the file with spectrogram 16 and that doesn't produce a readable wave.
Rc universe won't let me attatch a wav file. Seems jpegs,gif,txt only.
Rc universe won't let me attatch a wav file. Seems jpegs,gif,txt only.
10-30-2008, 09:52 AM
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RE: Dopler wave o scope use
ok, with help of jburry i have dismissed the higher frequencies using spectrogram 16 and succeeded in achieving this 4 stroke wave files speed.
10-30-2008, 02:54 PM
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RE: Dopler wave o scope use
Fun it was, too.
Looks to me like a 4st doubles the number of octaves shown, likely from the every-second-revolution exhaust note. The display was more cluttered and busy than I'm used to with 4 strokes, but clear lines were there when the frequencies were restricted on the vertical scale.
The model has a 14x8 prop and is said to tack in the 9K range on the ground. No accurate ground tach available, but it's a clue...
We were able to plug the resulting Spectrogram frequencies into the speed calc xls sheet, which gave us something on the order of 98mph and 11,500 RPM. These numbers jive fairly well with either a slippery ship (she is exceeding geometric pitch speed by somewhere near 10%, which we know can and does happen), or the speed could be somewhat inflated by an improperly flown pass.
I dislike automated software, prefer to measure and plug in values myself. That's why I choose spectrogram/spreadsheet over wave-o-scope. Ask software to make a decision for you, and 7 times outta 10, it'll choose what you didn't want....
It was fun dopplerin' that, Spitz.
J
Looks to me like a 4st doubles the number of octaves shown, likely from the every-second-revolution exhaust note. The display was more cluttered and busy than I'm used to with 4 strokes, but clear lines were there when the frequencies were restricted on the vertical scale.
The model has a 14x8 prop and is said to tack in the 9K range on the ground. No accurate ground tach available, but it's a clue...
We were able to plug the resulting Spectrogram frequencies into the speed calc xls sheet, which gave us something on the order of 98mph and 11,500 RPM. These numbers jive fairly well with either a slippery ship (she is exceeding geometric pitch speed by somewhere near 10%, which we know can and does happen), or the speed could be somewhat inflated by an improperly flown pass.
I dislike automated software, prefer to measure and plug in values myself. That's why I choose spectrogram/spreadsheet over wave-o-scope. Ask software to make a decision for you, and 7 times outta 10, it'll choose what you didn't want....
It was fun dopplerin' that, Spitz.
J
10-30-2008, 03:09 PM
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RE: Dopler wave o scope use
So when you type in your values the RPM is given at octave 6? Or better yet could you give a summery of how to get your values with the spreadsheet....Gofastz
10-31-2008, 09:59 PM
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RE: Dopler wave o scope use
In Mk1spitfire's post above, #13, there's a link to the spreadsheet file. The thread on that forum that links to the spreadsheet (link's at the upper left of the page) gives a complete explanation, by the guy that made the spreadsheet. I can't do better!
J
J
