How does GNSS-RTK Kit Base Station use to establish its absolute location? (SKU: KIT0198-US)

The GNSS-RTK kit (SKU: KIT0198-US) will show different locations between starts when both base and mobile units have not been moved. This is most likely due to the base station having no “known” absolute location. 

1.  How does the base station determine absolute location?

      a) Automomous GNSS averaging? If so how many data points are used in the averaging? Can the number of data points be changed? Can continous averaging be used?

      b) Initial RTK fix? If using this method, is there a way to continue to use additional fixs to improve estimate of absolute location?

      c) Some other method? What is the method?

2.  Is it possible to access the base station software? If so, how?