TY  - GEN
AU  - Kaplan,Elliott D.
AU  - Hegarty,C.
TI  - Understanding GPS : principles and applications: principles and applications 
SN  - 1580538940
U1  - 623.893 
PY  - 2006///
CY  - Boston
PB  - Artech House
KW  - Global Positioning System
ER  -