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

[Chaosrider]

The key to understanding metres/sec is to learn your drone's max speed from the specs.
eg For the Mavic 3:
5 m/s (C mode)
15 m/s (N mode)
19 m/s (S mode)

If you know your drone's max speed in Normal Mode is 15 m/s ... it's a simple matter to tell how much below (or above) max speed you are flying.

It's not about knowing the specs. It's about what naturally makes sense to me when I'm flying, and m/s doesn't.

YMMV

 

[Chaosrider]

m/s is used because is better when we use semi-short distances.
Example: If your max flight altitude is going to be 120m, it's easier to know that your climbing speed is 5m/s instead of 18Km/h.
The same reason we should use feet/s in Imperial System, Example: 400' Max Altitude, climb rate 16.4 fee/s instead than 11.8 miles/h.
It's easier and faster for our brains to comprehend/calculate how long is going to take to get that altitude if we use m/s and feet/s instead of larger units like Km/h or miles/h.

F/S is another alien measure for me. The OP got it right; 45 mph I intuitively understand from driving cars at that speed. F/S? M/S?

Alien!

 

[Faster]

F/S is another alien measure for me. The OP got it right; 45 mph I intuitively understand from driving cars at that speed. F/S? M/S?

Alien!

View attachment 148309

LOL, maybe is easier for me because of my other hobbies (hunting and Long Range shooting). When shooting we measure the projectile velocity in m/s or f/s, never in Km/h or miles/h.

 

[vindibona1]

m/s is used because is better when we use semi-short distances.
Example: If your max flight altitude is going to be 120m, it's easier to know that your climbing speed is 5m/s instead of 18Km/h.
The same reason we should use feet/s in Imperial System, Example: 400' Max Altitude, climb rate 16.4 fee/s instead than 11.8 miles/h.
It's easier and faster for our brains to comprehend/calculate how long is going to take to get that altitude if we use m/s and feet/s instead of larger units like Km/h or miles/h.

Yes, but if your settings are Imperial, and you've used Imperial all your life, M/S is relatively meaningless when one internalizes how fast the drone is going. M/S then becomes only relevant to those who know what percentage of max speed it's flying at; a useless figure when you can't relate it to your perception of speed.

I was curious about the Mini 2's max speed in m/s and googled "how fast can a dji mini 2 fly". I was really looking for m/s in the results menu, but what I came up was below. Mph and one Kph. Nowhere easily obtainable other than DJI's website or something referencing the actual Mini 2 specs could I find a m/s reference.

or
A joke, I'm sure. I didn't follow it. It's Ken Heron.

 

[vindibona1]

F/S is another alien measure for me. The OP got it right; 45 mph I intuitively understand from driving cars at that speed. F/S? M/S?

Alien!

F/S works when you're measuring bullet or projectile velocity as it usually is coupled with mass to determine energy. That measurement may or may not be converted to Mph, depending on what your unit reference is for sub or supersonic.

 

[whazzup]

It's just a frame of reference, and is similar to using a second language (most people translate into their native language even after being immersed for decades). Inasmuch as you can learn a second language, internal translation frames it for you.

Google tells me the conversion is:

Formula

multiply the speed value by 2.237

That makes it easy. If you have brain fog (or CRS* syndrome), just multiply x 2 and you are "close enough for government work".

For our incipient Mini 3's, the actual calculation of maximal speed is close enough to 2x method (at least for my purposes):

16 m/s (S Mode) -- 36 mph
10 m/s (N Mode) -- 22 mph
6 m/s (C Mode) -- 13 mph

Cheers!



* CRS = Can't Remember Squat syndrome

 

[Chaosrider]

LOL, maybe is easier for me because of my other hobbies (hunting and Long Range shooting). When shooting we measure the projectile velocity in m/s or f/s, never in Km/h or miles/h.

Ahhh, I had forgotten that, muzzle velocity is in f/s.

I guess that was a measurement just for shooting for me, and I never tried to relate it to anything else, so it was never an issue.

I hung up my "faster than a speeding bullet" cape a long time ago...

;-)

 

[EricJT]

Think what you want, but here in the US there was a push in the 60's to convert to the metric system. It was official... but didn't "take". Most folks still used Imperial measurements of feet, yards, miles, acres. As the global economy came over here we knew we'd have to be able to use (convert) to cm, mm, M and Km. But to many of us it was like having to translate to a different language rather than know the language. It seems that pretty much only the scientific community embraced the metric system fully. To the rest of us it was something to be "translated" into the familiar imperial measurements.

Yards into approximate meters could get us a spitball estimate of distance. Kph into Mph was a little harder (and disconcerting when I lived in Mexico and had a car). [Also seemed like an easy way to bump the price of gas when measured in litres.} BUT NOW "METERS PER SECOND"???? You lost me here. I can calculate Mph from Kph... But reducing the distance and the time into a m/s equation has just left me in the dust.

So why m/s as opposed to Kph or Mph. . I know we can select the unit of measurement in our drones'

Having worked in Finance my whole career and thankfully retired....converting from mph to kph is either multiplying or dividing by a factor of 1.6....to go from kph to meters per second,
multiply by .278.....kph x 1,000 / 3,600.

Mind you my family thinks I am weird because I can do math in my head....pretty simple when there is not much else in there.

 

[Meta4]

That's all well and good. But many of us, speaking for myself, I want a sense of speed that I can relate to.

If metric units are too much for you, just set your app to display in imperial units and don't worry yourself with other units.

 

[offtheback]

LOL
When was the last time you measured a 2x4 stud? Seem we pay for the whole 2x4 but only get 1-1/2 x 7-1/4

I believe nominal is the term

 

[Lets Fly]

LOL
When was the last time you measured a 2x4 stud? Seem we pay for the whole 2x4 but only get 1-1/2 x 7-1/4

1 1/2" x 3 1/2 ".

 

[Cymru]

I wish the drones, being effectively aircraft, used standard aviation measures - ie knots and feet.

However m/s makes more sense than km/h on these drones as the distances are short enough. It also makes the maths easier.

If my display says im 1000m away and im doing 10m/sec then its easy for me to know how long it'll take to cover that distance.
Its not as easy seeing its 1000m away and working out how long it takes at 36km/h...

I'd be happier if the imperial readout gave feet per minute or feet per second instead of mph for the same reason.

 

[Meta4]

I have to ask your profession or former, we can take it offline as well.

I worked with a lot of engineers and PHD chemist.

No disrespect meant but from your posts I need to ask. Some people I don't think
know are both are on point and trying to help.

Sorry ... I can't make any sense of your post or see its relevance to anything.
Perhaps the advice I gave in post #29 would be helpful for you too?

 

[KennethH]

Think what you want, but here in the US there was a push in the 60's to convert to the metric system. It was official... but didn't "take". Most folks still used Imperial measurements of feet, yards, miles, acres. As the global economy came over here we knew we'd have to be able to use (convert) to cm, mm, M and Km. But to many of us it was like having to translate to a different language rather than know the language. It seems that pretty much only the scientific community embraced the metric system fully. To the rest of us it was something to be "translated" into the familiar imperial measurements.

Yards into approximate meters could get us a spitball estimate of distance. Kph into Mph was a little harder (and disconcerting when I lived in Mexico and had a car). [Also seemed like an easy way to bump the price of gas when measured in litres.} BUT NOW "METERS PER SECOND"???? You lost me here. I can calculate Mph from Kph... But reducing the distance and the time into a m/s equation has just left me in the dust.

So why m/s as opposed to Kph or Mph. . I know we can select the unit of measurement in our drones' preferences. But often when looking at demo vids and only m/s is provided as speed, I have to pause and go "Alexa....". Until I started droning I had never heard speed spoken of as m/s. Is there really a point to using m/s when the world uses either mph or kph? I know we can change it to meet our needs, but when used as the sole reference it just doesn't register with me as something I can grasp as actual speed. "Splain it to me, Lucia".

I'm just thankful I found where to choose Imperial over Metric in DJI Fly. I can't deal in Metric. It was bad enough when our new '77 Nissan 280Z had both on the speedometer.

 

[AnzacJack]

As we are talking aviation , Id actually like to see my speed in knots.

 

[vindibona1]

As we are talking aviation , Id actually like to see my speed in knots.

It's whatever you can relate to. If you're a pilot and have a feel how long it takes to get from from A to B knots, or in fixed wing techno, stall speed, then you're golden. Most of us who drive cars will have a feel for mph or kph because at 45mph we Americans innately know how fast fast is. I would be willing to bet that 90+ percent of us have no internal relationship to m/s other than the math, assuming we have a feel for static metric measurements. I suppose like anything else one might be able to learn. But why, when we have a perfectly good speed relationship in units that have stood the test of time, though not the easiest to work with mathematically.

In 1975 Congress passed the Metric Conversion Act pretty much mandating that the official units of measurement would be metric. I can't explain it, but it never took. We still pretty much use inches, feet, yards, miles, degrees in Fahrenheit and are still, 47 years later are ensconced in the imperial system. Of course many of us have metric tools as much of the goods we receive are from outside the US. When I lived in Mexico, if my car's speedometer didn't register in Kph, I'd be so confused how fast I was driving... or should I say slow. No clue how hot it was based on degrees Celsius and still can't do a conversion in my head (this is the hardest).

However, relating to the speed of a projectile is a whole 'nother thing. IMO DJI should ditch ms/ and change to Mph/Kph and be done with it. so that you don't have to be a nuclear physicist to know how fast fast is.

 

[AnzacJack]

Smoots per hour?

 

[EsaT]

I wonder how whacked the 2x4 would seem if you tried to measure it in cm?

Metric equivalent is 5x10 cm.
But that makes bigger numbers, so even here in Finland 2x4 is used at least unofficially.
2x5, 2x6 and 5x8 are certainly nicer than equivalent in centimeters.

Though who ever is in "output" end would no doubt prefer same number but inch replaced by centimeter.
Two of the last were in the menu when spending four hours in sawmill today.
While now being in "input" end (what's the name for one helping to roll log on table and attach rear end?) I've spend hundred+ hours picking up ready lumber.

LOL
When was the last time you measured a 2x4 stud? Seem we pay for the whole 2x4 but only get 1-1/2 x 7-1/4

Well, isn't that just goal in capitalism?
Buyer paying full price for less/having to pay extra to get full thing.

 

[EsaT]

So why m/s as opposed to Kph or Mph.

Scale of the units is certainly far better fit for drone flying:
Neither kilometer or mile are good fit for measuring distance in VFR/VLOS flying.
And batteries don't exactly give flight time measured in hours either.
Minute would be far closer to time scale of typical flight for taking few pictures.

M/S is an entirely alien unit to me. I can do most of the basic conversions in my head, kg-->lbs, km-->miles, cm-->inches, maybe a couple of others. But M/S just seems WRONG somehow.

Divide km/h (or kph) by 3.6 and you'll get m/s.
1 m/s = 3.6 km/h
10 m/s = 36 km/h

Also 1 m/s is very accurately equal to 2 knots.
Proper aviation doesn't use any weird mph, but knots.

 

[LoudThunder]

Most folks still used Imperial measurements of feet, yards, miles,

I will give you my personal reason why I will never convert to the metric system.. I am 5' 8" and my size 10 shoe is almost exactly 12" (one foot -- no pun intended…) and due to my smaller stature, when I pace off a distance, I can very comfortably pace in one-yard steps… If I try to pace off one-meter, it's very uncomfortable and I look like I'm trying to take "Giant Steps" and it looks foolish…

Now, for a more esoterica reason, I live in Hampton Roads, Virginia, just a few miles from NASA/Langley Research Center. And from my back yard I can see the Gantry that Neil Armstrong and other astronauts practiced moon landings and test aircraft crashes to drop tests for the Orion Spacecraft…



My previous next-door neighbor is an Astrophysics who worked on many NASA Space Projects and one project that he worked on was the Mars Climate Orbiter in 1999 and it missed the planet and is probably stuck orbiting the sun…

One team at NASA used the metric system of millimeters and meters in its calculations, while the contractor (Lockheed Martin) used the Imperial system of inches, feet, and pounds.

Due to the difference in the systems, the orbiter actually entered the atmosphere when it performed it's orbital burn and that overheated the engine, causing the engine to shut down early and the orbiter then missed the planet and wound up in a solar orbit; out where no "metric-man" has gone before…

He also worked the Genesis Comet Probe that crashed into the Nevada Desert after the parachute failed to deploy because some technician did not know the difference between up and down. The technician held the assembly illustrations upside down and inserted the Explosive bolts that would deploy the parachute upside down. When the bolts exploded, only the nut end blows off. Since the bolt head with the long shaft was in the wrong way, the cover for the parachute would not fall off. Not a metric mistake, but just as stupid a mistake.

Neither problem or mistake was my neighbor, but as I teased him, he's guilty by association… He now works for one of the NASA Space Contractors…