Understanding the Velocity Indicator

xCav8r · Post by **xCav8r** » Sun Aug 30, 2009 2:16 pm

I'm a total n00b just checking out the demo. When I turn IDS off, rotate, and strafe vertically, I get readings on my velocity indicator that I don't understand. Minor changes in heading and pitch, for example, make for readings that jump from -4000 to 4000. One of my friends suggested that it's indicating velocity relative to the orientation of the ship at the moment IDS was disengaged. If I'm not strafing, that does seem to be the case. For example, moving along at 1020 (what's this calibrated in? m/s?) and yawing 180 degrees makes for a reading of -1020. Still, the readings I get with a little bit of strafing and rotating seem incongruous with the "relative velocity indicator". What am I missing here?

MMaggio · Post by **MMaggio** » Sun Aug 30, 2009 2:44 pm

Turning IDS off allows the ship to coast at the last speed and direction set.
Rotating the ship on any axis does not affect actual ship heading or speed, but the speed indicator will show minus if you are facing backwards, even thos you are still travelling in the last direction & speed when IDS set.
Speed is in Km per hour.
Hope that helps.

xCav8r · Post by **xCav8r** » Sun Aug 30, 2009 3:04 pm

What you're saying confirms what my buddy thought about the indicator with IDS off, but it doesn't help me understand the readings I'm seeing that vary so drastically from -4000 to 4000 with just minor rotations (and strafing). I'm still puzzled.

Wow, I was way off thinking kilometers per second. (I meant to write "km/s" instead of "m/s".) I would never have guessed KPH. Now is the speed academic? It seems to me that in the training where I land on the planet that I'm traveling a much greater distance than KPH would indicate. Seems like I'm missing something again.

[Edited on 8-30-2009 by xCav8r]

49rTbird · Post by **49rTbird** » Sun Aug 30, 2009 3:09 pm

Hello xCav8r, welcome to the forum and the Sim. C U in MP sometime. Enjoy!:)

MMaggio · Post by **MMaggio** » Sun Aug 30, 2009 4:07 pm

I may have "mis-spoke" , as politicians often do about the speed.
As for the speed indicator only showing + or - for the speed even if you are only turned slightly, I believe it is merely an indication of wether you are past 90* left or right. Since the speed and direction are always the same, rotating the axis beyond 90* will show a minus. Just as rotating the axis only a few degrees will still show a plus.
Maybe Vice can make it clearer.

Post by **Marvin** » Sun Aug 30, 2009 5:22 pm

On inertial, if you rotate you ship by 180 degrees, you're effectively flying backward. Ergo, you will have a negative velocity equal (but opposite) to your forward velocity. Either way, the "speed-o-meter" shouldn't exceed that forward velocity.

You will see some high numbers, though. But those are indications of attitude diviation* in the horizontal and vertical ... the readouts being located at the top of the radar screen.

* Edit: That would be your ship's attitude diviation (where you're pointed) from your flight path (where you're going).

[Edited on 8-30-2009 by Marvin]

xCav8r · Post by **xCav8r** » Sun Aug 30, 2009 7:43 pm

I appreciate all the replies. Maybe I'm just obtuse and don't recognize the obvious, but I'm still confused by the readings of -4000 and 4000 on my velocity indicator from strafing and minor rotations. These comments seem only to confirm what my buddy had suggested without helping me understand the extreme readings.

Maarschalk · Post by **Maarschalk** » Sun Aug 30, 2009 8:37 pm

Hi xCav8r, Welcome to the Game and Forum. The straffing velocity indicators -4000 and 4000 are your up and down velocity and sideways left and right maximum velocity. You could be sliding in a diagonal direction in a 3 Dimensional Space and think of the velocity indicators as your velocity vectors in 3D space. So if your straff up is at maximum of 4000 and your straff right is at maximum 4000 and your forward speed is 4000 on inertial
then your sliding in space along a diagonal vector of a cube upward to the right and forward. Your x vector=4000 your y vector is 4000 and your z vector=4000. Now if you turn around 180 degrees around your midpoint of gravity then you'll be flying backwards and your velocity vectors all will change to -4000. The negative and positive are just indicators of which direction your ship is facing in relation to your velocity. Remember in space there is no friction so your speed stays 4000 if you change to inertial when reaching your maximum speed. So if you change direction by turning around your center of gravity your speed and direction do not change but the way you are facing changes so the - and the + are telling you if your facing forward along your velocity vectors or backwards along your velocity vectors! And it changes from + to - or - to + when you turn more then 90 degrees to your left or right from your forward heading or from your backwards facing direction! I hope I did not confuse you more!;)

MMaggio · Post by **MMaggio** » Sun Aug 30, 2009 8:39 pm

You will not see gradual changes in speed as the ship turns. It's either PLUS or Minus the full set speed. Those are the only two options.
Doesn't matter wether you turn the ship on it's axis a little or a lot, the set speed is 4000, and it's always going to be 4000.
So, either the ship is facing more forward, which is Plus, or more aft, which would be Minus. But the ship is ALWAYS travelling at the same speed and direction, regardless of it's heading.
If that doesn't clear it up, I'll have to send you a diagram! LOL