Great Circle Mapper vs. Research Route

yourefired · **on:** April 10, 2008, 07:04:57 am

I noticed that there are significant discrepancies....I know we use GCM for distances and such, but I noticed something odd:

JFK-HNL is 4330nm according to GCM, 4983 statutory miles.
JFK-HNL on Research route is 4981nm.

JFK-SFO is 2247nm according to GCM, 2586 statutory miles.
JFK-SFO on research route is 2583nm.

JFK-LHR is 2999nm according to GCM, 3451 statutory miles.
JFK-LHR on research route is 3446nm.

I'm not sure if this is a bug or just a miscalculation or something, but it's kind of odd to have such a huge difference. Perhaps you entered in the distance in statutory miles rather than nautical miles and then marked it as nautical miles?

If you guys meant to do that, that's fine. But I almost always use GCM before using research route and then I'm just kind of surprised to see the differences.

SATA · **Reply #1 on:** April 10, 2008, 07:09:06 am

it isnt a bug i noticed this one day ago and theres some diffrence in the length :?

yourefired · **Reply #2 on:** April 10, 2008, 07:10:18 am

Looks to me that they used the distance in statutory miles and marked it nautical miles rather than using the actual nautical mile distance.

SATA · **Reply #3 on:** April 10, 2008, 07:12:36 am

yep looks like it

royaloyal · **Reply #4 on:** April 12, 2008, 03:53:33 am

yeah, its always like that, if you want to search in GCM, then use mi instead, it seems to be much more closer to the distance in the database between all airports

not sure is it a bug or what