GIS Mapping

Hello everyone. I do a large amount of work with surveying and GIS mapping systems and the curvature of the earth is a very important fact that we use to do our work. All of our maps and map projections depend on a round earth. Millions of contactors, municipal authorities, and developers use our maps every day to design structures, determine property ownership, and navigate efficiently. If you were to reproject our maps assuming a flat earth all of these calculations would not work properly. If you have ever applied for a building permit or looked at a map you have depended on a round earth.

Not only this, but the same thing applies to bouncing radio signals, like HAM radio off satelites to relay AROUND the world, or when a sniper takes a long range shot and has to factor in the curvature of the earth for proper shot placement. Not to mention bouncing signals radio signals off the moon that people like to do for fun experiments, are you telling us that all of the laws of physics are 100% wrong, and not only that you are qualified and even close to smart enough to tell us the "new" laws of physics? Get real, prove it to yourself. Try to send a radio signal halfway AROUND the world without bouncing it off the atmoSPHERE.

Any FE's?

Not only this, but the same thing applies to bouncing radio signals, like HAM radio off satelites to relay AROUND the world, or when a sniper takes a long range shot and has to factor in the curvature of the earth for proper shot placement. Not to mention bouncing signals radio signals off the moon that people like to do for fun experiments, are you telling us that all of the laws of physics are 100% wrong, and not only that you are qualified and even close to smart enough to tell us the "new" laws of physics? Get real, prove it to yourself. Try to send a radio signal halfway AROUND the world without bouncing it off the atmoSPHERE.

how in the hell far away would you have to be to factor in the curvature of the earth to hit a target?

Anything really past 1000 yards or so can be effected. When the sphere earth is rotating and something far away is moving, instead of it moving in a straight line that it is, it can appear that it is moving in a slightly curved path depending on how far away it is and acts as a "fake force" in physics (called the Coriolis effect). For instance a place that looks like it's not going in a straight line in the sky above that actually is or a boat doing the same in the distance. When you are taking a shot at something the size of a bowling ball (head) that is moving over a mile away, you have to take this curvature into effect and realize that your shot has to be slightly adjusted to where the person is actually going to to be when you take the shot, not where your eyes see the person. If the earth was flat and the sun and moon rotated around it like these people are saying, this effect wouldn't exists and long range sniper shots would be off.

Anything really past 1000 yards or so can be effected. When the sphere earth is rotating and something far away is moving, instead of it moving in a straight line that it is, it can appear that it is moving in a slightly curved path depending on how far away it is and acts as a "fake force" in physics (called the Coriolis effect). For instance a place that looks like it's not going in a straight line in the sky above that actually is or a boat doing the same in the distance. When you are taking a shot at something the size of a bowling ball (head) that is moving over a mile away, you have to take this curvature into effect and realize that your shot has to be slightly adjusted to where the person is actually going to to be when you take the shot, not where your eyes see the person. If the earth was flat and the sun and moon rotated around it like these people are saying, this effect wouldn't exists and long range sniper shots would be off.

i don't buy this. all the hours i've spent in marine corps marksmanship training and we never discussed this. i can' timagine any snipers (unless in a movie) taking a shot from more than 1000 yards away.

I'm going to have to call BS on that one too. It's absolutely part of the firing solution for anything (like artillery) that fires close to or over the horizon, but for small arms I can't see it.

The record shot was 1.5 miles, so yes snipers do take those long of shots, however rare they may be. according to a topic discussed on a message board over at discovery http://community.discovery.com/eve/forums/a/tpc/f/9741919888/m/7051979539
one of the senior members who I can only assume has the experience to back it up said "For a .30 cal with a launch velocity of about 2900 fps, fired from 38 deg latitude and fired due north, the left-right deviation due to the Coriolis Effect is about 10 inches at 1 mile." The effect is real and can effect long range shots. If you do a basic calculation without actually calculating the effect itself but only relative to the mile deviation, a 1000 yard shot in the right circumstance could move up to 5 inches. Is this likely? no, but ask a sniper with a windage meter and compass about to take a long range shot why he uses a compass for the shot....

By the way I am not an expert on sniper shooting i just have read about this effect and things shooters have to do for long range shots, but even the comment above saying they have to take it into effect for firing solutions proves that it is real and is just another way to show the earth isn't flat lol.

Quote from: earthizntflat on August 15, 2008, 09:23:21 AM

Anything really past 1000 yards or so can be effected. When the sphere earth is rotating and something far away is moving, instead of it moving in a straight line that it is, it can appear that it is moving in a slightly curved path depending on how far away it is and acts as a "fake force" in physics (called the Coriolis effect). For instance a place that looks like it's not going in a straight line in the sky above that actually is or a boat doing the same in the distance. When you are taking a shot at something the size of a bowling ball (head) that is moving over a mile away, you have to take this curvature into effect and realize that your shot has to be slightly adjusted to where the person is actually going to to be when you take the shot, not where your eyes see the person. If the earth was flat and the sun and moon rotated around it like these people are saying, this effect wouldn't exists and long range sniper shots would be off.

i don't buy this. all the hours i've spent in marine corps marksmanship training and we never discussed this. i can' timagine any snipers (unless in a movie) taking a shot from more than 1000 yards away.

It sounds like you generally don't know what you're talking about then. Read this, Scout sniper takes out mortar crew from more than 1000 yards. That's USMC in Iraq. http://www.mfr.usmc.mil/Archive/2005.01/sniperkill.html

Also I submit the following quote for your consideration.:
"There are three components to the Coriolis Effect which accounts for the apparent shift in the target position while a projectile is in flight. For rifle shooters we only need two components because we are not shooting directly away from the earth for great distances as would a missile for example. The horizontal component of this rotation results in a shift of impact point to the right (compared to line of sight) in the Northern hemisphere and to the left in the Southern hemisphere. There is also a vertical component which is caused as the target rises while it follows the arc of rotation. A due North (or South) will not have a vertical component but all other directions will have at least some Coriolis vertical component.

Under normal hunting conditions, the Coriolis Effect is minimal and can be ignored. At 600 yards, the effect becomes noticeable with a deviation of almost 1”. That value is now barely within the adjustment of scopes with 0.125 MOA /click, so it can also be ignored. At F-Class distances of 1,000 yards, it is something which must be taken into consideration.

The deflection increases as one approaches the earth’s poles. Hence, at 1,000 yards there is more deflection at Bisley in the United Kingdom (3.2”) with a latitude of 51oN than in Albuquerque, New Mexico (2.4”) with a latitude of 35oN. As such, being able to calculate the Coriolis Effect for all latitudes at which you may be shooting is a major benefit of the Nightforce program.

There is also a vertical deflection component to the Coriolis Effect. This is determined by the shooting direction in degrees from north. That value is calculated simultaneously with the windage deflection by the Nightforce program. However, there is a “problem” with the pull-down menu for calculation of the Coriolis Effect. It is for the northern hemisphere. It really isn’t much of a problem. A modification to the pull-down menu for the southern hemisphere has been prepared as I write this. In the meantime, I wrote to Gerald Perry (www.Perry-Systems.com) who developed the Nightforce Ballistic Program and licensed it to Nightforce for commercial distribution worldwide and he gave me the following information which will permit readers in the Southern Hemisphere to use the existing menu. Input your latitude and shooting direction (Azimuth - degrees from north) and the deflection values will be correct. You simply interpret the horizontal deflection as left, rather than right. The vertical components are unchanged. Up is up and down is down.

Should you even bother to consider factoring in the Coriolis Effect? We could probably find just as many shooters who choose to ignore it as those who want it calculated. The same discussion could be had in reference to spin drift. The bottom line is, we can’t settle the argument, but the availability of the calculations are there if you want them."
http://www.chuckhawks.com/nightforce_ballistic_program.htm

My guess is you don't know jack shit. You may want to search Cpl. Rob Furlong or Carlos Hathcock as both have confirmed kills past 2000 meters.

well, in the intrest of civility i will concede defeat. i am not a sniper but i never denied confirmed kills beyond 1000 yards to a mile and a half.

this seems to help me understand better
http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/gifs/coriolis.mov

Awesome, Very interesting stuff. I will keep it in mind for my next shot 

Any FE'r wanna dispute this? I would love to hear how calculations of radio being bounced off the moon and the time it takes to come back work the same with it being 3000 feet away....

It's a shame we have the genuine discussion about the impact of a curved earth on various disciplines and the FEers have nothing to say.

It sounds like you generally don't know what you're talking about then. Read this

...My guess is you don't know jack shit.

I know it was your first post, but you might try being polite.  It does tend to impress people about as much as your actual knowledge about a subject.

By the way, good post otherwise.  It had information with references.

i don't buy this. all the hours i've spent in marine corps marksmanship training and we never discussed this. i can' timagine any snipers (unless in a movie) taking a shot from more than 1000 yards away.
[/quote]

Really?  a marine who doesn't know basic military history?  There was a rairoad gun used in World War 1...The Paris gun. 210mm, 35 drgree elevation, 1600 m/s.  range was 130 km. The shell weighed 210 pounds. 170 second trajectory. The Germans used it to shell the city of Paris.  the Coriolis effect which deals with the rotation of the earth...(look it up) actually effected  trajectory calculations. 

The gun was fired at an azimuth of 232 degrees (west-southwest) from Crépy-en Laon, which was at a latitude of 49.5 degrees North. The gunners had to account for the fact that the projectiles landed to the right of where they would have hit if there were no Coriolis effect.

The gun and any like it were banned by the treaty of Versailles.  The only other gun that came close, but was never completed was one that was being built in Iraq, and subsequently dismantled at tth conclusion of Operation Desert Storm.

I wouldn't scrutinize his military history knowledge considering you took that post almost word for word from wiki.

Yes I did.  That's because i didn't have my copy of Jane's International Defense review handy.

Only gungho diggits remember that kind of superfluous nonsense that has nothing to do with your real job anyway.

Only gungho diggits remember that kind of superfluous nonsense that has nothing to do with your real job anyway.

And what, exactly would my job be?

That wasn't directed at you specifically.  The point was that knowledge of history is usually not pertinent to a job.

That wasn't directed at you specifically.  The point was that knowledge of history is usually not pertinent to a job.

True, but I fail to see what a job and studying history have to do with one another.  Ah well...

any FE'rs care to chime in as to why this does not prove the earth is round? I don't see any way to dispute this fact, so I guess it's proven. (trying to get a FE to show otherwise)

Bueller.....Bueller.....