Activity VII

Objective: The focus of this activity is to perform zero-baseline retransmission setup analysis with different sets of smartphones

Measurement setup:

The smartphone was logging RINEX data in the open sky and a Trimble Reference was logging at the same time to be used as a reference station.


Processing tools

Data logging

ISTA Logger ++


Xiaomi MI8, HTC Nexus 9, Samsung S8 and Huawei M8

Rooftop antenna



30 dB tunable L1 GPS source

Retransmission antenna


RefStation. Receiver

-Axtesys Receiver

Processing software



The data was logged using ISTALogger and was then converted to Rinex format. The GPS only analysis was done with the data because Nexus 9 was the only smartphone other than MI8 which could provide good and continuous carrier phase measurements (due to duty cycle off by default) at the time of analysis. But, was only capable to log GPS and GLONASS.

Carrier phase measurements from Xiaomi MI8 showed integer ambiguity with small jumps due to the quantization problem also confirmed from Broadcom. Nexus 9 logged continuous carrier phase data but ambiguities were not an integer in nature and thus difficult to fix.

Samsung S8 with the duty cycle non-configurable was not able to provide a continuous carrier phase.



Positioning Results from MI8

 Log files: Coming Soon.


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