TOP106 APC & PPP

GPS/GNSS
1

Hey folks,

After learning the SparkFun TOP106 was classified with IGS/NGS, I decided to reprocess some of my data with the antenna information included in the RINEX header. I submitted a test file to NRCan’s PPP tool, but received the following message:

Warning : Although an antenna record was located in the RINEX file, no phase centre information could be found in the IGS/NGS file for your antenna. Estimated height should be used with caution. Ensure that both the antenna type and the RINEX header record "ANT # / TYPE " are valid.

Shouldn’t the antenna phase center (APC) be readily available to NRCan? I’ve included my RINEX header below.

Cheers,
Adam

     3.04           OBSERVATION DATA    M: Mixed            RINEX VERSION / TYPE
CONVBIN demo5 b34i                      20241009 114709 UTC PGM / RUN BY / DATE 
log: /data/LWL_1_20240718_190000.ubx                        COMMENT             
format: u-blox UBX                                          COMMENT             
format: u-blox UBX                                          COMMENT             
                                                            MARKER NAME         
                                                            MARKER NUMBER       
                                                            MARKER TYPE         
                                                            OBSERVER / AGENCY   
                                                            REC # / TYPE / VERS 
SFETOP106           NONE                                    ANT # / TYPE        
 -2375404.5029 -2098919.6167  5517511.9026                  APPROX POSITION XYZ 
        0.0000        0.0000        0.0000                  ANTENNA: DELTA H/E/N
G    8 C1C L1C D1C S1C C2X L2X D2X S2X                      SYS / # / OBS TYPES 
R    8 C1C L1C D1C S1C C2C L2C D2C S2C                      SYS / # / OBS TYPES 
  2024    07    18    19    01   00.9880000     GPS         TIME OF FIRST OBS   
  2024    07    18    22    00   16.9940000     GPS         TIME OF LAST OBS    
G L1C                                                       SYS / PHASE SHIFT   
G L2X  0.00000                                              SYS / PHASE SHIFT   
R L1C                                                       SYS / PHASE SHIFT   
R L2C                                                       SYS / PHASE SHIFT   
 17 R02 -4 R03  5 R04  6 R05  1 R06 -4 R09 -2 R10 -7 R11  0 GLONASS SLOT / FRQ #
    R12 -1 R13 -2 R14 -7 R18 -3 R19  3 R20  2 R21  4 R22 -3 GLONASS SLOT / FRQ #
    R25 -5                                                  GLONASS SLOT / FRQ #
 C1C    0.000 C1P    0.000 C2C    0.000 C2P    0.000        GLONASS COD/PHS/BIS 
                                                            END OF HEADER
2

The form looks wrong, suppose to be a Serial Number, and then the Model

P807                                                        MARKER NAME
Glen Mattioli       UNAVCO                                  OBSERVER / AGENCY
5250K40713          TRIMBLE NETR9       5.42                REC # / TYPE / VERS
0220364721          TRM59800.80     SCIT                    ANT # / TYPE
  -843664.9480 -5435917.4520  3217955.7020                  APPROX POSITION XYZ
        0.0083        0.0000        0.0000                  ANTENNA: DELTA H/E/N

Where’s the ANTEX file situated, so I don’t have to go dig it up…

Model “NONE” probably goes to some default

3

Hi Clive,

ANTEX is here: https://geodesy.noaa.gov/ANTCAL/LoadFile?file=SFETOP106_NONE.atx

SparkFun has their own option in the dropdown, here: Antenna Calibrations

Cheers,
Adam

4

Hum.

Could it really be as simple as swapping the order? The ANTEX file is “TYPE / SERIAL NO”, whereas RINEX is “# / TYPE”.

When I reversed the order, the PPP warning disappeared and the antenna type and phase center information showed in the output (see below).

Good order
Screen Shot 2024-10-10 at 9.43.21 PM

Bad order
Screen Shot 2024-10-10 at 9.43.26 PM

Problem solved?

Cheers,
Adam

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