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What people call transversal velocity is actually angular velocity
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Reaver Glitterstim
The Scope
Gallente Federation
#1 - 2013-07-16 20:55:59 UTC  |  Edited by: Reaver Glitterstim
Major edit: I mistakenly wrote the article saying radial velocity when I actually meant angular velocity. Thanks Mara Rinn for pointing out this error! Radial velocity is the speed at which the distance between you and your target is changing.

I don't understand why so many EVE vets make this rookie mistake. I don't believe they actually think that transversal velocity is what's important, even the most green pilots often know that you can get under a ship's guns. So why the blunder of nomenclature? I understand that many veteran EVE players are not math whizzes (though most of them probably are), and I also realize that the word 'transversal' sounds better than 'angular', but that doesn't change the fact that they are two distinctly different functions.

What are transversal and angular velocity, you ask? Well it's quite simple. Transversal velocity is the net velocity you are moving in comparison with another body. To use an example, you are driving down a highway at 200kph in your hot rod and passing up cars in either lane. The other cars are all traveling at about 80kph in relation to the highway surface. You are thus going 120kph faster than they are. You have 120kph of transversal velocity in relation to the cars going in the same direction as you, but 280kph of transversal velocity in relation to the cars in the other lane. This transversal number actually only applies while you are passing each car, however. While you are heading directly toward or away from a car, your transversal with them is zero. Cars going perpendicular to you at the intersection ahead actually have only 80kph of transversal on you while they're in the intersection because you're going straight toward them, but more before and after the intersection due to you going very fast in a direction semi-perpendicular to them. Transversal velocity is only affected by the velocity of you and your target, and is not dependent on the distance to the target.

Angular velocity takes into account the distance to the target. If you are sitting still in a hidden fox hole in enemy territory, stationed near two roads which are parallel to each other, the cars on the closer road (assuming they are moving at the same velocity) have a greater angular velocity in relation to you. Calculating the actual angular velocity is complicated and requires knowledge of basic trigonometry, and I don't feel like getting into the calculations--besides, I'm certain I would mess them up something horrible. But the net effect is very simple to measure. Angular velocity is the velocity that your target is moving across your field of view. If it takes 3 seconds to move 18 arc minutes across your field of view, then its angular velocity in relation to you is 6 arc minutes/second, or 1 degree/10 seconds.

Now you might be asking, why is it important to note the distinction between transversal velocity and angular velocity? Simple. Turret tracking works on angular velocity with the target versus the target's signature radius. If you orbit your enemy at the same velocity and half the distance, you double the angular velocity between you two. This means that turrets must track twice as fast to hit you. Calculating turret tracking speed is pretty easy. The turret tracking in EVE is measured in radians per second. One radian is a measure of circumference (such as an orbit) equal to the radius of said circumference, and there are 2*pi radians in a circumference or orbit. So if you are orbiting your target at 40km, then the distance around the orbit is 2*pi*40km, or about 251km. Every 40km you move, the turrets on your target must turn 1 radian to track you (assuming your signature radius is the same as the signature resolution of the turrets). If your target is an Abaddon firing tachyon beam lasers at you with a tracking speed of 0.02262 radians per second, and the signature radius of your Megathron is equal to their signature resolution (400m), then the guns need 1/0.02262 or 44.2 seconds to track you across the whole 40km, or 277.8 seconds to track you in one full orbit. Since the orbit is 251km, you could be orbiting at 251/277.8 or 0.9035 km/s (903.5m/s) in the orbit and be matching the guns' tracking. Now if you moved closer to your target, the guns would still need the same amount of time to track you in a full orbit, but you would have a smaller orbit to make, so it would be easier to defeat their tracking.

Another cool trick to learn is how to shoot a moving target: if you match your target's velocity, then you cancel out angular and transversal velocity alike (though angular is the only one that is important). The way to do this is to move in the same direction your target is moving. If you see a Rifter target moving along on afterburner at 1059m/s in a straight line, ignoring you, you could flip on your Megathron's microwarpdrive and raise your velocity to 979m/s and point your ship in the same direction as the Rifter--not toward the Rifter, but parallel to it, then you should see that little box around it start moving much more slowly on your screen. If you overheat your MWD, you can raise your max velocity to 1397m/s and then throttle down a tiny bit using your throttle pad in the HUD, and potentially match the Rifter's velocity almost exactly. Once you see it stop drifting across your screen, fire your railguns and blap the bastard!

FT Diomedes: "Reaver, sometimes I wonder what you are thinking when you sit down to post."

Frostys Virpio: "We have to give it to him that he does put more effort than the vast majority in his idea but damn does it sometime come out of nowhere."
Unsuccessful At Everything
The Troll Bridge
#2 - 2013-07-16 21:01:44 UTC
Im sure you posted this wall of text to win some arguement that youre having with someone, what is the TLDR for those of us who don't feel the need to read?

Since the cessation of their usefulness is imminent, may I appropriate your belongings?
Reaver Glitterstim
The Scope
Gallente Federation
#3 - 2013-07-16 21:04:38 UTC
That transversal =/= to radial, and that radial velocity matters in EVE and that transversal does not.

FT Diomedes: "Reaver, sometimes I wonder what you are thinking when you sit down to post."

Frostys Virpio: "We have to give it to him that he does put more effort than the vast majority in his idea but damn does it sometime come out of nowhere."
SirScarecrow
Pinky and the Brain.
#4 - 2013-07-16 21:07:54 UTC
Reaver Glitterstim wrote:
I don't understand why so many EVE vets make this rookie mistake. I don't believe they actually think that transversal velocity is what's important, even the most green pilots often know that you can get under a ship's guns. So why the blunder of nomenclature? I understand that many veteran EVE players are not math whizzes (though most of them probably are), and I also realize that the word 'transversal' sounds better than 'radial', but that doesn't change the fact that they are two distinctly different functions.

What are transversal and radial velocity, you ask? Well it's quite simple. Transversal velocity is the net velocity you are moving in comparison with another body. To use an example, you are driving down a highway at 200kph in your hot rod and passing up cars in either lane. The other cars are all traveling at about 80kph in relation to the highway surface. You are thus going 120kph faster than they are. You have 120kph of transversal velocity in relation to the cars going in the same direction as you, but 280kph of transversal velocity in relation to the cars in the other lane. This transversal number actually only applies while you are passing each car, however. While you are heading directly toward or away from a car, your transversal with them is zero. Cars going perpendicular to you at the intersection ahead actually have only 80kph of transversal on you while they're in the intersection because you're going straight toward them, but more before and after the intersection due to you going very fast in a direction semi-perpendicular to them. Transversal velocity is only affected by the velocity of you and your target, and is not dependent on the distance to the target.

Radial velocity takes into account the distance to the target. If you are sitting still in a hidden fox hole in enemy territory, stationed near two roads which are parallel to each other, the cars on the closer road (assuming they are moving at the same velocity) have a greater radial velocity in relation to you. Calculating the actual radial velocity is complicated and requires knowledge of basic trigonometry, and I don't feel like getting into the calculations--besides, I'm certain I would mess them up something horrible. But the net effect is very simple to measure. Radial velocity is the velocity that your target is moving across your field of view. If it takes 3 seconds to move 18 arc minutes across your field of view, then its radial velocity in relation to you is 6 arc minutes/second, or 1 degree/10 seconds.

Now you might be asking, why is it important to note the distinction between transversal velocity and radial velocity? Simple. Turret tracking works on radial velocity with the target versus the target's signature radius. If you orbit your enemy at the same velocity and half the distance, you double the radial velocity between you two. This means that turrets must track twice as fast to hit you. Calculating turret tracking speed is pretty easy. The turret tracking in EVE is measured in radians per second. One radian is a measure of circumference (such as an orbit) equal to the radius of said circumference, and there are 2*pi radians in a circumference or orbit. So if you are orbiting your target at 40km, then the distance around the orbit is 2*pi*40km, or about 251km. Every 40km you move, the turrets on your target must turn 1 radian to track you (assuming your signature radius is the same as the signature resolution of the turrets). If your target is an Abaddon firing tachyon beam lasers at you with a tracking speed of 0.02262 radians per second, and the signature radius of your Megathron is equal to their signature resolution (400m), then the guns need 1/0.02262 or 44.2 seconds to track you across the whole 40km, or 277.8 seconds to track you in one full orbit. Since the orbit is 251km, you could be orbiting at 251/277.8 or 0.9035 km/s (903.5m/s) in the orbit and be matching the guns' tracking. Now if you moved closer to your target, the guns would still need the same amount of time to track you in a full orbit, but you would have a smaller orbit to make, so it would be easier to defeat their tracking.

Another cool trick to learn is how to shoot a moving target: if you match your target's velocity, then you cancel out radial and transversal velocity alike (though radial is the only one that is important). The way to do this is to move in the same direction your target is moving. If you see a Rifter target moving along on afterburner at 1059m/s in a straight line, ignoring you, you could flip on your Megathron's microwarpdrive and raise your velocity to 979m/s and point your ship in the same direction as the Rifter--not toward the Rifter, but parallel to it, then you should see that little box around it start moving much more slowly on your screen. If you overheat your MWD, you can raise your max velocity to 1397m/s and then throttle down a tiny bit using your throttle pad in the HUD, and potentially match the Rifter's velocity almost exactly. Once you see it stop drifting across your screen, fire your railguns and blap the bastard!


oh wow, you are now officially a rocket scientist. Tell me something, after you posted all this non-essential garble, do you have more friends now?
Ajion
Duelism
#5 - 2013-07-16 21:11:54 UTC
I for one, approve of his block of text.
E-2C Hawkeye
HOW to PEG SAFETY
#6 - 2013-07-16 21:13:15 UTC
Unsuccessful At Everything wrote:
Im sure you posted this wall of text to win some arguement that youre having with someone, what is the TLDR for those of us who don't feel the need to read?

He is saying we are using the wrong terminology. He is correct. When you or (your computer) calculates a firing solution this information is processed but we in eve call it traverse velocity. Main reason is because we have a column for it in our UI Big smile
Joepopo
Worthless Carebears
The Initiative.
#7 - 2013-07-16 21:13:47 UTC
SirScarecrow wrote:


oh wow, you are now officially a rocket scientist.


Being a rocket scientist myself, I must say that I am amazed SirScarecrow math.

.
Reaver Glitterstim
The Scope
Gallente Federation
#8 - 2013-07-16 21:19:51 UTC
E-2C Hawkeye wrote:
Unsuccessful At Everything wrote:
Im sure you posted this wall of text to win some arguement that youre having with someone, what is the TLDR for those of us who don't feel the need to read?

He is saying we are using the wrong terminology. He is correct. When you or (your computer) calculates a firing solution this information is processed but we in eve call it traverse velocity. Main reason is because we have a column for it in our UI Big smile

Actually the UI column labeled transversal velocity does represent actual transversal velocity, and is thus only a partial readout to use for determining the radial velocity between you and your target. Using the term transversal when you mean radial will confuse people into trusting the transversal readout on the UI and failing because of it.

FT Diomedes: "Reaver, sometimes I wonder what you are thinking when you sit down to post."

Frostys Virpio: "We have to give it to him that he does put more effort than the vast majority in his idea but damn does it sometime come out of nowhere."
Nalha Saldana
Aliastra
Gallente Federation
#9 - 2013-07-16 22:47:11 UTC
Finally someone else who realized this, I've been telling people to put radial velocity on overview for years now.
Mara Rinn
Cosmic Goo Convertor
#10 - 2013-07-16 23:32:00 UTC
$op =~ s/radial/angular/ig

If you're going to correct people, at least be right about it. Radial velocity is the radial component of the target's velocity vector, from the observer's point of view. A radial is a line from the centre of the circle to the edge. Since the component of velocity you are actually concerned about is the one changing the position of the target in your subjective sky, you want the angular velocity which is the rate at which the angle between you and the target is changing.

Radians per second is an angular measure, since radians are a way of measuring angles (360° in a circle, 2π radians in a circle). Thus a measure of radians per second is the rate over time at which the angle is changing.

So please go back through that screed and replace radial with angular, and everyone can come away from this experience a little better educated.

Day 0 Advice for New Players
Reaver Glitterstim
The Scope
Gallente Federation
#11 - 2013-07-16 23:37:24 UTC
@ Mara Rinn: You're right, I don't know how I've missed this all these years.

@ Nalha Saldana: I've been telling people this for over a year now, too.

FT Diomedes: "Reaver, sometimes I wonder what you are thinking when you sit down to post."

Frostys Virpio: "We have to give it to him that he does put more effort than the vast majority in his idea but damn does it sometime come out of nowhere."
Tippia
Sunshine and Lollipops
#12 - 2013-07-16 23:47:13 UTC  |  Edited by: Tippia
Reaver Glitterstim wrote:
That transversal =/= to radial, and that radial velocity matters in EVE and that transversal does not.
This is incorrect. Radial velocity doesn't matter at all (other than to provide speed that helps mitigate missile damage), whereas angular velocity matters against turrets, since it's the velocity against which their tracking is compared.

Transversal is simply angular velocity expressed in m/s rather than rad/s, (where angular v = transversal / distance). Transversal is important — it just isn't the complete measure, since it lacks that important distance factor that turns it into angular v, which is why the same transversal speed creates vastly different hit chances at 10km than it does at 100km.

Nalha Saldana wrote:
Finally someone else who realized this, I've been telling people to put radial velocity on overview for years now.
You should stop, and instead tell them to put angular velocity on the overview. Radial has its uses — it tells you the closing speed of the target (negative = you're closing in, positive = he's getting farther away), but it is of absolutely no use in terms of determining how easy a target is to hit.


edit: Oh well, that's what I get for queuing up a number of answers and being late to the answering-party. P
Klandi
Consortium of stella Technologies
#13 - 2013-07-17 00:02:09 UTC
Reaver, an interesting read that accomplished what exactly?

What was the motive for writing this - what outcome did you want to achieve and do you think you reached your objective.

I am aware of my own ignorance and have checked my emotional quotient - thanks for asking
Reaver Glitterstim
The Scope
Gallente Federation
#14 - 2013-07-17 00:06:25 UTC
I'm just trying to raise awareness that transversal velocity is not what people treat it as. I'd say I succeeded there.Cool

FT Diomedes: "Reaver, sometimes I wonder what you are thinking when you sit down to post."

Frostys Virpio: "We have to give it to him that he does put more effort than the vast majority in his idea but damn does it sometime come out of nowhere."
Infinity Ziona
Sebiestor Tribe
Minmatar Republic
#15 - 2013-07-17 01:49:36 UTC
This doesnt matter because EvE ignores realistic math / physics. Its just as difficult to hit a ship at zero velocity while orbiting as it is to hit an object orbiting at speed while you are stationary.

CCP Fozzie “We can see how much money people are making in nullsec and it is, a gigantic amount, a shit-ton… in null sec anomalies. “*

Kaalrus pwned..... :)
Mara Rinn
Cosmic Goo Convertor
#16 - 2013-07-17 01:54:33 UTC
Infinity Ziona wrote:
This doesnt matter because EvE ignores realistic math / physics. Its just as difficult to hit a ship at zero velocity while orbiting as it is to hit an object orbiting at speed while you are stationary.


Thus the aim is to get angular velocity high enough for them to miss you, but low enough for you to hit them. At the same time balance your optimal & falloff so they will miss you more than you miss them. Which leads to the concept of a "skilled pilot" who builds a ship for certain optimal range, forward speed, agility, tracking and DPS, to kill the types of targets they are hunting.

Day 0 Advice for New Players
Tippia
Sunshine and Lollipops
#17 - 2013-07-17 01:57:25 UTC
Infinity Ziona wrote:
Its just as difficult to hit a ship at zero velocity while orbiting as it is to hit an object orbiting at speed while you are stationary.

Of course, since the relative motion is the same. Also, this.
Mara Rinn
Cosmic Goo Convertor
#18 - 2013-07-17 01:59:21 UTC  |  Edited by: Mara Rinn
Transverse velocity is also useful: it helps you know if you will be capable of matching vectors with the target. If your ship has a maximum speed of 1,500m/s and the target is transversing at 2000m/s there is no chance of matching, and you will have to contend with 500m/s of transverse velocity in the best case. At this point you learn the utility of long range webs.

Edit: in a thread calling out someone else for confusing two technical terms, it is unforgivable to confuse transverse velocity with traversal. Transverse is an adjective meaning "lying across" while traverse is a verb meaning "to cross".

http://www.englishforums.com/English/WhatMajorDifferenceBetween-DefinitionsTraverse/vvkwv/post.htm

“A skier will traverse a steep slope by following a transverse route across the mountain face.”

Day 0 Advice for New Players
Mara Rinn
Cosmic Goo Convertor
#19 - 2013-07-17 02:05:30 UTC  |  Edited by: Mara Rinn
Tippia wrote:
Infinity Ziona wrote:
Its just as difficult to hit a ship at zero velocity while orbiting as it is to hit an object orbiting at speed while you are stationary.

Of course, since the relative motion is the same. Also, this.


Labels, Tippia! The purple and red straight arrows are transverse velocity, the blue and green curved ones are angular velocity. Is that diagram part of a blog post?

Also useful reference: http://www.daviddarling.info/encyclopedia/T/transversevel.html

Day 0 Advice for New Players
Tiberius Mal
Pator Tech School
Minmatar Republic
#20 - 2013-07-17 02:08:09 UTC
i also feel vindicated as I had to sort this out all by myself earlier in my eve career. I knew the required overview changes and the reason why the numbers needed to be this or that, but I could not have provided the math to explain why that was the case.

long read, but interesting read. thanks for playing, now go out and kill something with this knowledge.
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