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Data collection for FPV distance

lobstermash

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Mentor
#1
Many people proclaim, with a good deal of conviction, all kinds of statements and generalisations that just aren't even close to true. I'm guilty of doing this on plenty of occasions myself.

FPV is a topic that seems to bring this out in people. I'm keen to try and collect some real data from people's FPV experiences and produce some sort of decoder that gives people a realistic indicator of what sort of distance you can expect from different frequencies, transmission power and antenna setups, and the relative impacts of atmospheric conditions, topography and terrain. Something that won't be able to be measured is ambient interference, and this may be a large confounding factor. Also, the data collected is going to contain distances well within the max of the system used because people don't fly to the limit all the time.

Let me know if you want to participate and feel free to recruit non-FTers in too. To get any meaningful data I'll need as many data points as possible per setup combination (probably 30-100 per setup to even start to get a trend). I've done up a quick Open Office spreadsheet with a data dictionary on the first sheet and a data reporting sheet on the second tab. I know that not all the units I've got in the spreadsheet are necessarily people's native units. I'd prefer data to be in the units specified, but if you really can't be bothered making my analysis easier, I'll convert them before I stick them in a master sheet.

Also feel free to tell me if I'm getting over-excited/ambitious or if there's someone already doing this. I plan to pool the data into a master sheet and post it with the results in an article on the main site.

EDIT: I've added the spreadsheet to Google Docs, which anyone following the link should be able to edit: https://docs.google.com/spreadsheet/ccc?key=0ApqXMzvBbsbddHdkTGpWWFV6TFBwYmxVWkJpNVB3d1E

NOTE: the 'data dictionary' is on the front sheet, the 'data entry' sheet is the next tab down the bottom of the page.
 
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#3
Ok I will add my experiences with 1.2 GHz but I have not flown it to the max yet... I think I can tell you the distance in about 4 weeks.
 

lobstermash

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Mentor
#4
Wow, Lobster - this is ambitious. And a great idea.
Yeah, ambitious, but this is a real need area for people getting into FPV and I've got the modelling skills to do it. I'm quite unbiased at present, as I've done very little FPV yet and am not particularly... attached to a frequency yet. I also don't have any data to contribute myself yet because I don't have a way of measuring distance and altitude yet.

So guys, please PM me your email address if you want to be involved and I'll send you the spreadsheet template for you to fill in.
 

bmsweb

Site Moderator
#5
Ok I will add my experiences with 1.2 GHz but I have not flown it to the max yet... I think I can tell you the distance in about 4 weeks.
Would really be interested in how far you go with it and the quality you get. Are you going to capture the OSD footage? It would be good to see.

lobstermash I'll be doing a series of test soon with different antennas etc. Will post my results.
 

lobstermash

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Mentor
#6
Cool. It seems like nobody wants me to email them (fair enough) the spreadsheet template, so I'll try and get it on here in table format for you all to cut and paste in your own spreadsheet. That'll have to wait until I get home (in about 7-8 hours). I've got about 13 parameters I want people to record so I can do some statistical analysis on the relative impact of each parameter and hopefully drill down to some sort of series of curves that show what to expect from a given setup in particular conditions.
 

lobstermash

Propaganda machine
Mentor
#8
It's never too late to start, teach! I've found FPV really easy to jump into. I'm sure you'd find the same. It's great for keeping the rc passion boiling too. I haven't had such a thrill from rc flying for many months.
 

lobstermash

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Mentor
#9
OK. Here goes. Hopefully Google Docs will do the job. I created the file in Open Calc to hopefully cover the people not using Office.

BEFORE adding data, please read the data dictionary on the first tab. Also, please make sure you've got data for each field - missing data makes analysis a lot harder. If it helps, print out the spreadsheet and keep it with you when you go flying and fill in at the field.

Let me know if you have any issues editing the document. I've made it so anyone can edit the doc if they can access the link. I might add an additional parameter of 'country', but I'm keen to keep the data anonymous.

https://docs.google.com/spreadsheet/ccc?key=0ApqXMzvBbsbddHdkTGpWWFV6TFBwYmxVWkJpNVB3d1E
 
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bmsweb

Site Moderator
#10
Should be interesting to see the results. I'll let you know as soon as I do the next round of testing. Was going to happen on Saturday, but my Wingman (some would call me his wingman), will be going to a Birthday Party.
 

lobstermash

Propaganda machine
Mentor
#11
I'm interested too! I'm just going to let people keep adding to it until I get a good sample size for each configuration. I'll post regular updates and some exploratory data analysis as I go as well.
 
#12
I'm interested too! I'm just going to let people keep adding to it until I get a good sample size for each configuration. I'll post regular updates and some exploratory data analysis as I go as well.
I dont know how much results you want per set up but maybe it is an idea to post this aswell on rcgroups.
 

lobstermash

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Mentor
#14
Hook, line and sinker, mate! We expect it from LOSers too!

@noname, I've thought of posting it on RCG. I'm trying to balance getting enough data (based on my experience, usually about 20 or so per setup to start getting anything meaningful) and getting too much (like thousands of data points). I'll start with the FT community first and see how we go, and if I'm not getting enough I'll tap into the scary world of RCG... Feel free to pass the link on to any non-FT friends/acquaintances etc. though.
 
#15
Hook, line and sinker, mate! We expect it from LOSers too!

@noname, I've thought of posting it on RCG. I'm trying to balance getting enough data (based on my experience, usually about 20 or so per setup to start getting anything meaningful) and getting too much (like thousands of data points). I'll start with the FT community first and see how we go, and if I'm not getting enough I'll tap into the scary world of RCG... Feel free to pass the link on to any non-FT friends/acquaintances etc. though.
I will tell people on dutch forums.... I think that you will get allot of people with 5.8 GHz setup. Does antennas also matter and what about the fpv setup? lc filter etc etc?

Arman
 

bmsweb

Site Moderator
#16
what about the fpv setup? lc filter etc etc?
Good Point Arman!

I know LC Filters can make an insane amount of difference. I had difficulty accepting this simple fact because I thought my video was good without it . . until someone showed me the difference. Its just a Ferrite Ring and capacitor!
 
#17
Good Point Arman!

I know LC Filters can make an insane amount of difference. I had difficulty accepting this simple fact because I thought my video was good without it . . until someone showed me the difference. Its just a Ferrite Ring and capacitor!
I am going to make an video about the lc filter since most people dont know/under estimate the power of this thing. I am trying to get some more in depth information about the lc filter. One week ago I went to the locall hobby club and one of the guys there gave me a HUGE ferrite ring almost as big as the lead rings that come with the bixler. I dont know if bigger is better but that could be a very good lc filter if bigger is better.
 

lobstermash

Propaganda machine
Mentor
#18
Yeah, antennas matter. I've got them in the spreadsheet. Do you think that lc filters affect distance enough to add it to the sheet, or do they just improve video quality?
 
#19
Just leave it out. This is more for the quality of the video i did not had the time yet to see if it gives you more range. (I dont have the space/battery capacity yet to fly on the boundaries of my fpv gear) Maybe paul can tell you something more about range wise. IMO you will get to much into detail.
 

bmsweb

Site Moderator
#20
Yeah, antennas matter. I've got them in the spreadsheet. Do you think that lc filters affect distance enough to add it to the sheet, or do they just improve video quality?
Yes it will. As the signal strength gets weaker, more noise appears in the video. Now if the video is cleaner to begin with, that means far less noise. You could be looking at 2 exactly the same systems except one would look a lot better. So you could conclude that one is better than the other.