measurement

[Guest jndery]

At 37W -78N Aproximately how many feet is represented by a chnge of 0.01 in D.DDDD.

Thanks

[Guest blscearce]

quote:

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Originally posted by jndery:

At 37W -78N Aproximately how many feet is represented by a chnge of 0.01 in D.DDDD.

Thanks

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The longitude doesn't make any difference.

 

The earth is about 25,000 miles in circumference around the equator. 25000 miles / 360 degrees = about 70 miles per degree at the equator.

 

The size of a latitude ring shrinks with the cosine of the latitude. So the 78N longitude ring is cos(78)*25000 miles long, or about 5200 miles. 5200 miles/360 degrees = about 14.5 miles per degree.

 

So 0.01 degrees at that latitude is .145 miles, or 760 feet.

 

Brian

[Guest blscearce]

quote:

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Originally posted by blscearce:

The longitude doesn't make any difference.

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Duh. What I should have said was that 0.01 degrees of latitude change is 760 feet, and (using the 360 degrees = 25000 miles figure) 0.01 degrees of longitude change is 3700 feet.

 

Brian

[Guest Markwell]

First, I think you mean 37N -78W , not 37W -78N. The coordinates you gave are somewhere in the northern section of Greenland.

 

Second - the work I did on this is for changes in minutes, even though you asked about degrees. Since someone else has already answered that question above, I'll take it to the next level.

 

Quick answer: Change in 0.001 minutes of latitude at that location is approximately 6.09 feet, change in 0.001 minutes of longitude is approximately 4.87 feet.

 

A little theory:

.

 

Hope this thoroughly confused and educated at the same time

 

[This message has been edited by Markwell (edited 24 October 2001).]

[Guest Markwell]

First, I think you mean 37N -78W , not 37W -78N. The coordinates you gave are somewhere in the northern section of Greenland.

 

Second - the work I did on this is for changes in minutes, even though you asked about degrees. Since someone else has already answered that question above, I'll take it to the next level.

 

Quick answer: Change in 0.001 minutes of latitude at that location is approximately 6.09 feet, change in 0.001 minutes of longitude is approximately 4.87 feet.

 

A little theory:

.

 

Hope this thoroughly confused and educated at the same time

 

[This message has been edited by Markwell (edited 24 October 2001).]

[Guest jndery]

Thank you all for the education it was most helpful. Though after doing the calculations I came up with different answers,

 

.01 degrees = 2904 ft Rough

.ooo1 " = 29ft " "

 

.01 degrees = .6 minutes = 36 sec

1 sec = 81ft

 

I hope I have it right

[Guest CharlieP]

Jndery, you have the .01 degrees of longitude about right but did not state the latitude. I get 3646 feet lat and 2912 feet lon for .01 degree at 37N. These values are about 600 times the figures Markwell gave for .001 minutes, since .01 degree is 600 times .001 minute.

 

FWIW,

CharlieP

[Guest Markwell]

9 miles (3648.352752 feet)

 

Change in 0.01° longitude 0.5518379 miles (2913.704112 feet)