Knowledge Base

If you are using SurvCE Version 2.08 or higher and you go into Equip / GPS Base or GPS Rover then tap the Receiver tab you will see a new checkbox labeled "NGS" in the upper right beside the slant and vertical toggle.   It is there for Internal Antennas and External Antenna's. 

Having the "NGS" box UNCHECKED should be the default to match user's previous measurements or existing GPS jobs. 

There is new Text shown now in the Receiver tab next to "Internal" antenna types that shows the L1 phase offset. {i.e. - "Internal (0.108 m)"}

The NGS option is available for all GPS drivers except Leica and has an affect on all non-zero, antenna phase offsets while turned on. It also affects the base antenna phase offset if the current driver has it on.

Most other data collection software packages (at least US ones) are defaulted with NGS unchecked also.

"AOAD/M T" is the name of the antenna NGS used to compare with the antenna they were testing. Since they always use the same antenna, the offset is always the same. 

You can see more info at the link below:
http://www.ngs.noaa.gov/ANTCAL/


Here is the message in SurvCE that pops up when you check the NGS box:
"Turning this option on will subtract the NGS AOAD/M_T bias from the antenna offset values to get an absolute offset.  This should not be used if you are combining with measurements that were done with Relative Offsets.  SurvCE Version 2.07 and older used only relative offsets {NGS unchecked}"




jg