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When did we start using M/S vs MPH or KPH???... and why?

There is a lot to be said for culture, and spacial familiarity. I can work mathematically with metric, but from the standpoint of internalizing distance and speed, there is not a chance that I can relate. When I lived in Mexico, the speed limits were Kph and the gasoline was litres. I always felt like car was going too slow for what the speedo read and always felt like I was getting ripped off when liters cost the same as $ in the US. I think it's too easy to cheat volume with litres. Sure a decimal is easier to calculate than fractions, but the ease comes with its downside as well, especially for those indoctrinated in imperial measurements. I was just a young boy when it was deemed that metric was the norm of the land... But metric still didn't take. You've think that after all these years when you look for dimensional specs on cars they'd be in metric. But no. Exclusively in inches/feet, even with the imports.
 
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As an FAA certificated ATP and CFI for many, many years (former airline pilot and still current flight instructor) I am well accustomed to aircraft (from light single-engine to transport category jets) flight speed measured in knots, vertical speed measured in feet/minute and and altitude measured in feet. The only aviation regulatory agencies in the world that don’t officially measure altitude in feet are China and Russia. They measure altitude in meters (not a precise enough measurement of altitude for aircraft in flight).

Our drones are indeed aircraft and as such, for me anyway, are best measured in mph, and feet for altitude or height above ground level. For vertical speed I would prefer ft/minute but will settle for mph. Meters per second is more of a scientific measurement but not one that is used in actual aircraft flying.
 
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If it wanted to adhere to aviation norm then knots and not mph would be far more beneficial.

Then again DJI is Chinese where aviation uses metres and metres/second. To them, if looking inward, the system is already correct.
 
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If it wanted to adhere to aviation norm then knots and not mph would be far more beneficial.

Then again DJI is Chinese where aviation uses metres and metres/second. To them, if looking inward, the system is already correct.
It is obvious to anyone who deals with Chinese products or companies that the Chinese have a different way of thinking and approaching things... and what they reveal in their personal and business practices.
 
Just found this thread, because of today’s post.
Surprised no one has mentioned the Hubble Space Telescope !
That was a rather expensive metric/imperial bugaboo !
 
That was a rather expensive metric/imperial bugaboo !
I thought the Hubble spherical aberration was caused by the manufacturer (Perkin-Elmer Corp) not taking Gravity into consideration when the mirror was ground and that the outer edge of the mirror "drooped" down "just a bit" by like 1/50 the thickness or a human hair, thus causing the light from the edge and the inner part of the mirror to not focus into the same spot…

As a side note, I always thought that the mirror's manufacturer, Perkin-Elmer, would be more appropriately named if they were a "Dairy" bottling milk and making butter…
 
The main thing I don 't care for with m/s is that none of the forecast apps I've come across is going to tell me estimated wind speeds at m/s , it's usually mph, kph, or kt as options.
Yeah... That too.
 
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I thought the Hubble spherical aberration was caused by the manufacturer (Perkin-Elmer Corp) not taking Gravity into consideration when the mirror was ground and that the outer edge of the mirror "drooped" down "just a bit" by like 1/50 the thickness or a human hair, thus causing the light from the edge and the inner part of the mirror to not focus into the same spot…

As a side note, I always thought that the mirror's manufacturer, Perkin-Elmer, would be more appropriately named if they were a "Dairy" bottling milk and making butter…
The version I have read was also metric vs imperial, maybe both whoopsies are applicable lol.

But Elmer would have me thinking of Mr Fudd, eeeek.
 
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Not that hubble was a conversion error at all (think Mars probes not HST) but its not really relevant.

Aviation does not use SI (engineering solutions should always use SI!).

DJI doesnt support the main worldwide standard for aviation measurements (feet, nautical miles, knots) although it does comply for the tiny areas of the world using metric such as China, Russia and so on.
 
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. . . but its not really relevant.

Sorry, gotta add one more thing . . .

Thought I remembered imperial vs metric from way back. Probably just premature speculation back then. Searching the story now turns up very little - just that there was some kind of error - like “they” want to hide it? Or it’s too complicated for us. Oh well. And you’re right about the relevance. 👍
 
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Km/h is a too high value for the distances we fly with our drone.

Remaining battery is shown in minutes and seconds, distance is shown in meters and if you set the speed to m/s you can easily do the math.

For example if you have the drone at 500m, you know that flying at 10m/s you'll be back home in 50 seconds.

And at long range, if you have the drone at 3000m and 10 minutes of battery left, you know that flying back at 10m/s you move 600m per minute, so you'll be home in 5 minutes, so no need to panic yet.

That being said, I fly in Km/h because I'm used to it, but m/s is definitely better; I know 40Km/h is around 11m/s so easy math calculations can still be done on the fly. Drones usually fly longer at a cruise speeds around 40Km/h.

On the other hand and although vastly used in aviation and sea, imperial units don't have any sense and just overcomplicate measurements and unit conversions, while metric is all about easy and exact unit conversions by just moving the point around.
 
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Km/h is a too high value for the distances we fly with our drone.

Remaining battery is shown in minutes and seconds, distance is shown in meters and if you set the speed to m/s you can easily do the math.

For example if you have the drone at 500m, you know that flying at 10m/s you'll be back home in 50 seconds.

And at long range, if you have the drone at 3000m and 10 minutes of battery left, you know that flying back at 10m/s you move 600m per minute, so you'll be home in 5 minutes, so no need to panic yet.

That being said, I fly in Km/h because I'm used to it, but m/s is definitely better; I know 40Km/h is around 11m/s so easy math calculations can still be done on the fly. Drones usually fly longer at a cruise speeds around 40Km/h.

On the other hand and although vastly used in aviation and sea, imperial units don't have any sense and just overcomplicate measurements and unit conversions, while metric is all about easy and exact unit conversions by just moving the point around.
That is until the pilot forgets to factor in the wind...
 
That is until the pilot forgets to factor in the wind...

That's why you always fly towards the wind at distances of more than 1Km, that way it pushes you on the way back.

Another good practice when long ranging is to start to return to home on green, don't wait to orange, that way you have plenty of battery to return even if the wind changes.
 
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The version I have read was also metric vs imperial, maybe both whoopsies are applicable lol.

But Elmer would have me thinking of Mr Fudd, eeeek.
It had nothing to do with either gravity or metric/imperial - it was caused by the incorrect insertion of a measuring rod in the calibration system, and then disregarding a secondary measurement that detected the error. Poor QC.
 
Km/h is a too high value for the distances we fly with our drone.
Anything per hour or per minute isn't really useful for drone flying as its too long a timescale.

Things "per second" are a lot easier for the timeframes and mental mathmatics used in drone flying.

Aviation wise i instinctively understand knots and feet per minute but they aren't useful real time indicators for me drone flying.
I want to know how far i can go in 30 seconds or how high it'll climb in 10 seconds and so on.

Thats why mine is currently set for metres / metres per second. The units themselves dont mean a lot to me but it allows useful on-the-fly calculations throughout the flight.
 
The main thing I don 't care for with m/s is that none of the forecast apps I've come across is going to tell me estimated wind speeds at m/s , it's usually mph, kph, or kt as options.
None?
It's in most I see.
This is from the one most referred to in the forum.
i-xjPJbcN-L.jpg
 
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That's completely unrelated to the measurement units used.
Maybe it does not have anything to do with measurement units used. But it has everything to do with the premise that the OP taking the remaining battery life (minutes and seconds…) and calculating how long it will take to return home based on meters per second and making it sound like science…
wind sock.png
 

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