Information particular to a specific product can be found on their product page in NavSpark Shop. Common information for NavSpark products are provided here.
NavSpark, NavSpark-BD, NavSpark-GL, NavSpark-mini User Guide (.pdf, ver 0.9)
NavSpark Programmer Guide (.pdf, version 0.4)
GNSS Viewer User Guide (.pdf 20151224)
Venus822A Datasheet (.pdf)
LEON3 User's Manual (.pdf, related sections 1, 7, 38, 47, 48, 65, 69)
NMEA Format (.pdf)
Binary Command Interface (.pdf, version 1.4.33, 20141211)
Venus 8 Baseband Memory Map (.pdf, 20151218)