On the RS2 does UBX log contain ARP adjustment?

I’m assuming the RS2 displays it’s reading with ARP taken into account so that the reading is at the bottom of the receiver. However, if I down load a UBX file, does it also have this information with it, or does the 135mm ARP have to be taken into account manually when using the UBX raw file for anything like PPK?

The UBX file does not contain that. The offset is accounted for in the Reachview 3 survey file (if you choose to have it entered). You do have to make sure that if using 3rd party software, you do not double the ARP by having the ARP entered in the RV3 app, and then again in the 3rd party software by entering the Antenna model with offsets.

When Reachview 3 writes data into the Rinex header (ie for opus) it will account for the .134 to have the correct antenna height entered.

1 Like

Does that mean that on the status page of the app, that the ‘Position’ reading has the ARP taken into account? I was under the impression that the RS2 always showed the reading at the bottom of the receiver.

Also, I apologize as I’m still new to RV3, is the survey file you mention the survey section of the app where pole height is entered when creating csv files? I was under the impression I only enter pole height there (for me 2 meters).

I am pretty sure that is the location to phase center. Because when you survey a point, you have the height of your pole to bottom of RS2 + .134 to account for offset. So 2.134 meters on a 2 meter pole. If you set the RS2 on top of a fire hydrant, your pole height is 0’, but you still have the 0.134 offset to determine the height at top of fire hydrant.


Does this mean that the only place ARP is automatically accounted for with the RS2 is within the RINEX header data that it produces, by including the Antenna Description? At all other places, we are reading phase center position (unless we manually include it with pole height)?

I will let someone verify as I do not want to tell you something incorrect. When you do a survey in the reachview app, it is automatically adding the .134 to the pole height. So that is “automatic”. But that value is being logged in the CSV file, not the UBX file. When you choose to create an Opus Log File, it will also automatically add the .134 to the pole height in the Rinex header info. Sorry if I have missed your question.


Hi @jherbranson,

Indeed, ReachView 3 app takes into account antenna offset when you’re working in RTK.

As for PPK, some post-processing software, including Emlid Studio, can take antenna type information from the observation file and automatically add offset. If this information is not available, you must add the offset manually.

As for observation files like RINEX, it can contain antenna type in the header. However, UBX is not a human-readable format and doesn’t include this info. However, you can add it in Emlid Studio when converting UBX to RINEX.


Hi guys,

I checked my reply and decided to add a few things to make it clearer.

ReachView 3 calculates the coordinates of the antenna’s phase center. In the Survey project, you receive coordinates of the point on the ground. For that, you just need to enter the pole height. APC offset is taken into account automatically.

In PPK, software usually can apply APC offset according to the antenna type listed in the RINEX header.

As for the base position in the RINEX header, the antenna offset won’t affect the result much since these coordinates have a few-meter accuracy only. If you need to know precise base coordinates, you should determine them before your survey or set the base to a point with known coordinates.


I’m still unclear on something.
The rover Survey CSV on the right hand side has ‘Base Elevation’ is this the Ant Phase Centre(APC) or Ant Reference Point(ARP)?

Hi Troy,

Nice to see you back on our forum!

In “Base easting”, “Base northing”, “Base elevation” fields, you see the base’s antenna phase center (APC) coordinates. They are transmitted to the rover and recorded in the CSV file without any changes.

1 Like

Thanks for clearing that up Elena.

1 Like

The base coordinates (in UTM I think?), these are always just phase center, correct? Any antenna height or pole height are taken into account regarding base setup in relation to any monument that is being used and then the RTCM data sends out phase center only?

Hi @jherbranson,

Yes, a rover receives coordinates of a base’s phase center and record them to a CSV file in a projected coordinate system. These values take into account an antenna and survey pole height.

UPD. Fixed the typos

This topic was automatically closed 100 days after the last reply. New replies are no longer allowed.