The Pioneer SmartCradle for iPhones is compatible with all GPS enabled apps, including MotionX-GPS Drive and is the first of its kind to incorporate a built-in gyro sensor and accelerometer combined with an external antenna for improved GPS reception and location accuracy, even if GPS signals are limited by high rise buildings and tunnels.
America is planning to improve its satellite-navigation system further: next year, it will start launching a second generation of GPS satellites, which will offer greater accuracy for civilian users and, for military purposes, greater protection against the signal being jammed by an enemy.
For example, researchers in Arizona are using real-time kinematic global positioning systems, an ultra-precise version of GPS that can measure positions with sub-inch accuracy levels, to control weeds in cotton fields with steel cultivators.