Question : invalid dates on gps tracking systems

Hi

I own/run a gps tracking system so I see a lot of gps data sent by gps units. With the units i use, gps data is classified as A or V. A means the date, time and gps positional information is guaranteed to be correct. V means the data isn't guaranteed.

Whenever i encounter an invalid date in a gps string it is always in the past and it is almost always in the year 2005.

Is there any reason for this because it isn't a co-incidence

thanks

Answer : invalid dates on gps tracking systems

Raw data:

http://www.codepedia.com/1/The+GPRMC+Sentence

From the GPS we have $GPRMC,040302.663,A,3939.7,N,10506.6,W,0.27,358.86,220909,,*1A

220909 - means September (09), 22th, 2009. From 2009 we see only 09.

If you see 2005, I'd say it is a default value either in the GPS receiver or in the driver or the application you use.

Of course, if you will say that your GPS works with the binary protocol, there is a real default value defined by the protocol for the minimal year. But it is 2001, if I remember correctly.