The distance between the two graves was no more than 20 m (as far as we remember) but when we tried to find out the distance as recorded by the different GPS devices, at the two occasions, using an online Coordinate Distance Calculator, the result was a disappointing 1580 m – far from any reasonable excuse. And no wonder, the first reading was taken in 2007 probably with a simple device whereas the second reading was taken in 2015 using a modern application. But we could not be sure that the newer means also the better. To solve the mystery it is recommended, in similar cases, to use a third certified professional device in order to come to conclusions – which one, of the two, is the more accurate.
This experience gave me an idea for an interesting science fair project – to compare the coordinate readings of different Smartphone GPS applications for finding out the most accurate. The comparison could be done relatively to some known monument like the Eiffel Tower or the Statue of Liberty, etc., whose official coordinate information could be easily obtained from Wikipedia.
On the way, elementary students can exercise methods of coordinate representation - the conversion of (DD) Decimal Degrees to (DMS) degrees, minutes, and seconds and vice versa. Middle or high school students can try to calculate the distances themselves without using an online coordinate distance calculator.
The opportunity presented itself when we visited the East Coast (August 2015) and took coordinate readings at two tempting sites by two different GPS applications – Ground Zero (World Trade Center) and Statue of Liberty – and calculated the distance for each application, using online software, from the official coordinate point and compared.