Calculating the Polar Circumference of the Earth
The purpose of this lab was to become familiar with tools used for location identification, as well
as to calculate the polar circumference of the Earth. The equipment available for use was a GPS unit,
ground flags, a surveyor’s tape measure, a compass, and a laptop with Google Earth. By using a
compass, two points that ran along the same longitudinal line were picked on campus. The distance
between those two points was recorded using the surveyor’s tape measure. The latitudinal difference
between the two points was then computed by using the GPS unit to record the latitude at both points.
In a similar process, Google Earth was used to verify the answers obtained using the land markers. Two
pinpoints were placed along the same longitudinal line, and the ruler function was used to find the
distance between the two points. The latitudinal difference was also calculated between the two points.
A proportion was set up to calculate the polar circumference of the Earth using both methods. The polar
circumference of the Earth found using the first method was (5.4135 x 10⁷ m). The polar circumference
of the Earth using the Google Earth method was (1.10459 x 10⁸ m). After verifying with an Internet
source, the polar circumference of the Earth is actually (4.0008 x 10⁷ m), which is closer to the answer
from the first method. The percent error using the first method was 35.3%. By calculating the distance
between two points on the same line of longitude, and find the latitudinal difference between them, the
polar circumference of the Earth can be found. By verifying on the Internet, the first method was more
accurate in calculating the polar circumference of the Earth than using Google Earth.