GPS/CORS coordinates

land butcher · Post by **land butcher** » Wed Jun 02, 2010 3:49 pm

I recently noticed that the difference between 2000.35 and 2007 coordinates for LBC1 are about 5ft different. I didn't check but I assume others changed about that much also.
Anyone know why the big change. I know we are moving here, but not 5ft in 7 years.

dmi · Post by **dmi** » Wed Jun 02, 2010 5:32 pm

For every station there is a log kept and the answers will be in there, if in fact the station was relocated.

land butcher · Post by **land butcher** » Mon Jun 07, 2010 11:56 am

Well maybe someone can explain this to me.

CORS sta LBC1 in Long Beach.
In comparing the values between the 2007 NGS data sheet and 2007 Sopac data sheet the Lat/Longs agree to the 5th decimal place but the meters are different X by 0.72m, Y by 1.32m

Even 2000 XYs differ.

Steve Martin · Post by **Steve Martin** » Mon Jun 07, 2010 12:04 pm

On the CSRC web site the X,Y,& Z are published on the ITRF 2005 datum while the Lat, Long & ellip. ht. are published in NAD83 (NSRS2007.00) datum so you are not comparing apples with apples there.

land butcher · Post by **land butcher** » Mon Jun 07, 2010 1:15 pm

thank you.