I have a Trimble R10 and need to upload static sessions to OPUS. What is the correct measurement that I need to use? Do I need to reference the ARP or Phase Center?
OPUS assumes ARP and makes you manually enter its height above the mark (not slant).?ÿ There are drawings on the NGS site (when it is available) showing where the ARP is for most models.?ÿ It is usually the bottom where an antenna screws onto a pole, but I am not familiar with that model.
The phase center is a point in an electric field. So that's not something you can measure. Not with a tape measure, anyway. You want the ARP, which is always the mounting point.?ÿ?ÿ
?ÿ
I think OPUS is looking for the height at the top of the quick release/ bottom of antenna (0.05 m up from BQR)
As Squirltech said, the ARP (Antenna Reference Point) is what OPUS expects.?ÿ The ARP varies for different antennas.
Below is the ARP drawing for the Trimble R10, same for version 1 or 2, at the bottom of the antenna/receiver itself.
So if using the lever extension sold by Trimble, you would need to measure your slant height (D in the diagram from Squireltech) in the field, calculate true height (C in that same diagram), then add the distance from A to C in the diagram, 0.656 feet.?ÿ You would then enter that calculate Height to ARP into OPUS.
If you use TBC and a Trimble DC, then you don't have to worry about any converting, be sure you pick the correct option in the DC when you measure, download it into TBC, then send to OPUS, no need to RINEX or convert the HI. If you don't have TBC and need to convert remember to calculate the correct the slant height and then add to the APR.?ÿ