What are users entering for Antenna Phase Center (APC) in third party apps & software?

I put out a question to Microsurvey and below is the response from them. @julia.shestakova What would be good to know though for FURTHER EXACT CLARIFICATION, is the 134mm Antenna Phase Center (APC) (from bottom of unit (Antenna Reference Point (ARP) to APC) an AVERAGE of L1 & L2 of the RS2/RS2+/RS3? Or is the ARP to APC to L1 ONLY?

Microsurvey response:


1 - Only the L1 offset is required. But we have not worked with the M2 models before, only the RS and RS2. So after entering in that L1 offset, I would check against known points to confirm if it’s correct.

2 - Because these are untested M2 models, you can try either the Emlid - Reach or NMEA - Basic for the Make - Model. Again, untested, so cannot say for sure which will be better. But APC settings are not included in the Windows version for the Emlid - RS driver. (The Android one does, but it’s for the RS2 model)

3 - The antenna height won’t reflect the offset values, so just enter what the pole measurement is to the bottom of the receiver or measure point. (whatever that L1 offset is referenced to related to the pole).

4 - I don’t believe you need to do any average, just the L1 offset is OK. But since this is the M2 model, I would recommend testing it thoroughly to confirm.

As a reference, we have a couple of articles here that might help if you use the RS or RS2 models:



My question to Microsurvey:

I have a couple Emlid M2’s and TOP106 multi-band antennas.

So the points I am testing are correctly measured, what exactly should the settings be in FieldGenius if ONLY one field to provide the "ARP to APC (L1) Offset - Vertical" is available but the antenna has BOTH L1 & L2? L1: 43.60mm L2: 39.60mm. Should we use L1 or AVERAGE both L1 & L2: 41.6mm? Same if using a L1 L2 L5 L6 multiband antenna in the future? Average or use just L1 ONLY? Not exactly clear in the help file.

For the MAKE, is it OK to select the Emlid Model: Reach RS and enter correct Antenna Height settings or do we need to select the NMEA Make? Wonder if the Reach RS model specific driver has built in APC settings that may interfere?

Rover pole from tip to ARP (bottom of TOP106) is typical 2m pole.

I notice when entering the ARP to APC in the field entry, the Antenna Height in FG just stays at rover pole height of 2m? Doesn’t reflect / add the additional height to the APC? So not sure exactly if calculations going on in the background?

Are the settings correct below? Or should ARP to APC be the average 41.6mm? Or should the “Measured Height”: just include the total of 2m pole and 43.6mm L1 (or average?) = 2.0436mm and do not enter anything for the ARP to APC? Not sure what the other 2 offsets are (Measure Point to ARP Offset - Horizontal & Vertical)?

Thank you!


to add to confusion:

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