It appears that you are looking at a data sheet for a different GPS module than the Skytraq S1315F. The S1315F does speak NMEA but it is best used in the Skytraq binary format. Which I am sure is what you are seeing.
You can get very accurate position fixes with the S1315F but you either need access to a nearby base station's data or you need two receivers, one stationary, one moving..and realtime calculation of your position using both is such a heavily CPU-intensive task that Arduinos can't do. However, lots of other CPUs can.
However, if you download Skytraq's GPSviewer software you should be able to easily switch it to NMEA and write the configuration to flash- then you will have a very
nice GPS chip capable of 20 Hz updates. The serial port speed can vary from 4800 baud to 115200. Its configurable.
For how to use the binary data, see http://gpspp.sakura.ne.jp/rtklib/