Re: Coriolis Info - According to LoadBase 2.0
All of the italics text below is taken directly from Patagonia Ballistic's LoadBase 2.0 users manual. I understand all of this text except for the underlined portion of the very last sentence. Can anyone tell me what that means? First it seems to infer that vertical deflection is maximum at the equator, but then it states that BOTH deflections (vertical and horizontal) are null at the Equator...
Beyond my question, this text clearly states that the direction of fire is required to determine vertical deflection (high or low hits), but that horizontal deflection (horizontal drift) is independent of the shooter's direction of fire (Azimuth). Working with the program, both horizontal drift and vertical deflections are maximum at the poles of the earth and have zero values at the equator.
I have underlined the word Azimuth in the sentence addressing vertical deflection to emphasize that the direction of fire is a required factor to calculate vertical coriolis deflections. And I have underlined the input parameters required to calculate horizontal coriolis drift to make it clear that the quantity of horizontal drift is completely independent of Azimuth (direction of fire).
Hope this is helpful.
PS: If anyone can explain that last sentence to me, I'd be grateful!
"Coriolis acceleration has two fundamental effects, sometimes not clearly distinguished one from the other.
First, a vertical deflection which balances Velocity, Distance, Latitude and Azimuth ( bearing ) to the target.
The second one, the horizontal deflection, takes into account Velocity, Latitude and Distance.
The effect depends upon where on the Earth's surface the gun is and the cardinal direction to the target.
For example, shooting at a target with a 270° azimuth ( from East to West ) causes an impact slightly lower than is experienced when shooting in the opposite direction.
Easterly bearing causes high shots, while westerly bearing causes low shots.
As one moves to higher latitudes ( north or south ) from the Equator, the apparent lateral movement of the bullet becomes greater
This acceleration has two fundamental effects, sometimes not clearly distinguished one from the other.
First, a vertical deflection which balances Velocity, Distance, Latitude and Azimuth ( bearing ) to the target.
The second one, the horizontal deflection, takes into account Velocity, Latitude and Distance.
The HORIZONTAL deflection will cause a bullet to drift to the right in the northern hemisphere and to the left in the southern hemisphere.
The VERTICAL deflection will cause a bullet to fall short or long, in terms of distance, since the Coriolis force ( a fictitious one ) makes gravity to weaken a little or get some reinforcement, this depending on the azimuth of the target.
The difference in the length of the trajectory is due to the velocity imparted to the projectile by the rotation of the earth.
Drift from Coriolis acceleration is maximum at the poles and negligible at the Equator.
The acceleration also affects range, but in the opposite sense, being maximum when fired along the Equator and negligible at the poles, and both deflections are null at the Equator line."
