Geneq SXBlue GPS Reference Manual page 25

To properly evaluate one receiver against another statically, they should be using identical
correction input (from an external source) and also share the same antenna using a power
splitter (equipped with appropriate DC-blocking of the receivers and a bias-T to externally
power the antenna). With this type of setup, the errors in the system are identical with the
exception of receiver noise.
Although this is a comparison of the GPS performance quality of a receiver, it excludes
other performance merits of a GPS engine. The dynamic ability of a receiver should be
compared in a similar way with the test subjects sharing the same antenna. Unless a
receiver is moving, its software filters are not stressed in a similar manner to the final
product application. When testing dynamically, a much more accurate reference would
need to be used, such as an RTK system so that a 'truth' position per epoch is available.
Further, there are other performance merits of a GPS engine, such as its ability to maintain
a lock on GPS and SBAS satellites. In this case, the same GPS antenna should be shared
between the receiver test subjects. For the sake of comparing the tracking availability of
one receiver to another, no accurate 'truth' system is required, unless performance testing is
also to be analyzed. Again, an RTK system would be required; however, it's questionable
how its performance will fair with environments where there are numerous obstructions,
such as foliage. Other methods of providing a truth reference may need to be provided
through observation times on surveyed monuments or traversing well-known routes.
If you require assistance in developing a test setup or procedure for evaluating the SXBlue
GPS, please contact Geneq.
SXBlue GPS Reference Manual 10