Currently the NGS is using relative antenna calibration but will switch to absolute antenna calibration soon. How will this affect legacy GPS projects when you add new data?
Will your manufacturer support absolute calibration in your software?
Will it simply be replacing the antenna file?
Paul in PA
My [limited] understanding of that issue is that there will be some variation in heights (depending on several factors), BUT very little if any in the horizontal component. Bear in mind that this change will be accompanied by a new International Terrestrial Reference Frame (ITRF-2008) AND (more importantly for most of us), a NEW Realization of NAD83 (NAD83[CORS96a]).
There WILL BE differences, but the antenna calibration issue is only one of the reasons for these differences. For one thing, crustal displacement across EIGHT (8) years (2002-2010) is going to be a significant factor out here in the West. The NEW Realization will be based on MUCH MORE observational data on the National CORS, newer and improved models (ocean loading, atmospheric loading, etc. etc.), and PAGES has been refined and updated on a fairly regular basis over the last few years.
I don't expect to see any “problems” in the the Eastern Great Basin (from my standpoint), but some projects MIGHT benefit from re-processing using the Newer constraints, models, and maybe even software.
My GUESS is...that most of the “changes” will fall under the signal to noise threshold of most of the legacy projects done by the average surveyor.
Loyal
WTF, we paid these government employees to come up with the datum they espoused and now they admit that their findings are AFU!
SPC is history!... and now NGS is reverting to IGS at a cost of millions and maybe billions of dollars.
Call your senator & congressman as this type of waste of taxpayer money has got to stop!
Especially the federal and state employees that thought you had a pension, just like I thought the money I put into Social Security & 401K would be there... as a senile Ronald Regan said... "a government big enough to give you what you want... is strong enough to take away every thing you have"!
TDD can I get amen?