others

pthread

https://computing.llnl.gov/tutorials/pthreads/

http://www.cs.kent.edu/~ruttan/sysprog/lectures/multi-thread/multi-thread.html#preface

Rs232

http://www.cmrr.umn.edu/~strupp/serial.html

Qyoto & Jambi

http://zetcode.com/

Ellipsoid reference 

http://zh.wikipedia.org/wiki/%E6%A4%AD%E5%9C%86

WGS84

Semi-major axis a = 6 378 137.0 m

Semi-minor axis b ≈ 6 356 752.314 245 m

GRS 80

Semi-major axis a = 6 378 137.0 m

Semi-minor axis b ≈  6 356 752.314 140 m