I am looking inside gpsd.fix ( class gpsfix ) and i see that there is a lot of ep_ variables, like, ept, epv, epx, epy epc, epd, eps, i looked inside gps.py and there is not commentary of what these variables are.
I am sure that is so easy that i am afraid of asking but... ¿What are this variables?
Maybe because i am Spanish i do not recognise the acronym.