# Investigation on Reference Frames and Time Systems in Multi-GNSS
## 1 Introduction
It turns out that updating the firmware often affects the GNSS-dependent receiver bias. There are however examples of changes of the receiver-dependent bias which are uncorrelated with a firmware update. A table of \"individual\" calibrations, for each receiver and each GNSS time offset is presented. \begin{table}
\begin{tabular}{c c c c c c} \hline
**ID** & **City** & **Country** & **Domes** & **Receiver** & **Antenna** & **Start Date** \\ \hline BBYS & Banka Bystrica & Slovak Republic & 11514M001 & Trimble NET89 & TRMS950800.00 & 1 January 2014 \\ BOXO & BorowskaCora & Poland & 12207M002 & Toppen EUROCARD & ASHT0034 GC\_M & 21 June 2015 \\ BRST & Best & France & 10004M004 & Trimble NET89 & TRMS57971.00 & 1 January 2014 \\ BRUX & Brussels & Belgium & 13101M01001 & Septronio POLAK474R & JAVRINGANT\_DM & 1 January 2014 \\ CAEN & Caen & France & 19994M001 & Leica GR25771.00 & 1 January 2014 \\ CEBR & Cebreros & Spain & 13408M001 & Septronio POLAK4 & SEPCHOKE\_MC & 1 January 2014 \\ COMO & Como & Italy & 12761M001 & Toppen E\_GCD & TPSCR3\_GCD & 21 June 2015 \\ COMO & Como & Italy & 12761M001 & Toppen NET-G & TPSCR3\_GCD & 19 October 2016 \\ COMO & Como & Italy & 12761M001 & Toppen NET-G & TPSCR3\_G & 7 February 2017 \\ DJF1 & Delft & The Netherlands & 13520M009 & Trimble NET89 & LIEARE25R3 & 1 January 2014 \\ DYNG & Dyonsios & Greece & 12602M006 & Trimble NET87 & TRMS95000.00 & 2 March 2015 \\ GANP & Ganove & Slovak Republic & 11515M001 & Trimble NET89 & TRMS95971.00 & 1 January 2014 \\ GANP & Ganove & Slovak Republic & 11515M001 & Trimble NET89 & TRMS95000.0 & 6 February 2017 \\ GOP7 & Ondrejov & Slovak Republic & 11502M006 & Javad TRE\_G3 TH DELTA & LIEARE25R4 & 1 January 2014 \\ GOP7 & Ondrejov & Slovak Republic & 115202M006 & Trimble NET89 & LIEARE25R4 & 1 January 2014 \\ HOFN & Hoefin & Iceland & 10204M002 & Leica GR25 & LIEARE25R4 & 1 January 2014 \\ ICMI & Firenze & Italy & 12701M003 & Toppen ODOSSEY\_E & TPSCR3G & 21 June 2015 \\ KIRU & Kiruna & Sweden & 10403M002 & Septronio POLAK4 & SEPCHOKE\_MC & 1 January 2014 \\ MGE & Roma & Italy & 12772M001 & Leica GR25 & LIEARE25R4 & 1 January 2014 \\ MAS1 & Maspalomas & Spain & 13103M002 & Septronio POLAK4 & LIEARE25R4 & 25 October 2015 \\ MIVL & Marne-la-Vallee & France & 10092M01 & Leica GR25 & TRMS5791.00 & 1 January 2014 \\ NVA2 & Ny Asleund & Norway & 10317M008 & Javad TRE\_G3 TH DELTA & JAV\_RINGANT\_G3T & 25 October 2015 \\ OGB4 & Oberaffenhofen & Germany & 14208M007 & Javad TRE\_G3 TH DELTA & JAV\_RINGANT\_G3T & 25 October 2015 \\ PALO & Padova & Italy & 12750S001 & Leica GR10 & LIEARE25R4 & 1 January 2014 \\ PEN2 & Penc & Hungary & 1206M007 & Leica GR102+ GNSS & LIEARE25R4 & 2 March 2015 \\ POTS & Potsdam & Germany & 14106M003 & Javad TRE\_G3 TH DELTA & JAV\_RINGANT\_G3T & 2 March 2015 \\ REDU & Redu & Belgium & 13102M001 & Septronio POLAK4 & SEPCHOKE\_MC & 2 March 2015 \\ REYK & Reykjavk & Iceland & 10202M001 & Leica GR25 & LIEARE25R4 & 2 March 2015 \\ SULP & Liv & Ukraine & 12366M001 & Toppen NET-G3 & TPSCR3\_GCD & 21 June 2015 \\ TISE & Toulouse & France & 10003M09 & Trimble NET89 & TRMS95000.00 & 2 March 2015 \\ VILL & Villafranca & Spain & 13406M001 & Septronio POLAK4 & SEPCHOKE\_MC & 25 October 2015 \\ WROC & Wiroclaw & Poland & 12271M001 & Leica GR25 & LIEARE25R4 & 2 March 2015 \\ WTZ3 & Bad Koettering & Germany & 14201M0015 & Javad TRE\_G3 TH DELTA & LIEARE25R3 & 25 October 2015 \\ WTZZ & Bad Koettering & Germany & 14201M014 & Javad TRE\_G3 TH DELTA & LIEARE25R3 & 1 January 2014 \\ ZIMJ & Zimmnerwald & Switzerland & 14001M006 & Javad TRE\_G3 TH DELTA & JAVRINGANT\_DM & 1 January 2014 \\ \hline \end{tabular}
\end{table} 
Table 1: List of stations included in the analysis.