便宜又精准的GPS接收器Piksi即将面世

Alexander

据科技博客Gizmodo刊文，一种新型的定位系统Piksi即将面世，这种定位系统可以精确到几厘米范围内。原文编译如下：

    假如你在兴奋地操控一台自制无人机，迟早你会希望它飞到你视野之外的区域。要想更精确地追踪其方位，只能精确到五米范围内的普通GPS是无法满足这一需求的。几位工程师已经在创意方案的众筹网站平台Kickstarter上成功启动开发一种新型接收器：Piksi，据称这种接收器能精确到几厘米范围内。

    GPS是一项伟大的发明，不过它在测算位置方面也有自身的局限性。首先，一个GPS码位长度约300米，也就是说，即使通过四个卫星的信号同时测算，最多也只能精确到几米范围内。而且，电离层会造成信号的延迟，也会导致误差。

    Piksi用两种方式来规避这些问题同时提高精确度，它除了测量卫星发出的GPS代码外，还同时测量代码的19厘米波长相位。使用一种算法处理，Piksi可以利用这些信息来提高定位精确度。此外，Piksi系统还使用附加接收器作为参考，进一步减少电离层延迟导致的误差。

    在Kickstarter活动期间，Piksi的单组售价为500美元。正式投入生产后，预计售价为900美元。虽然按照传统标准，Piksi的售价并不便宜，但与其他专业应用的产品动辄花费数千美元相比，这个价格已经相当合理了。而且假如你操控的是一架价值不菲的无人机，要精确地知道其飞行位置是很值得的——这个概念相当于精确地知道一大笔钱的位置。

    译者：高菲

    百度新闻与新华网国际频道合作稿件，转载请注明出处。

    Cheap Drone GPS Unit Is 100 Times More Accurate Than Your Phone

    If you're piloting a crazy homebrew quadracopter, sooner or later you're going to want to be able to pilot your UAV beyond where you can see it. And for more precise tracking, your ordinary GPS receiver's five-meter accuracy just ain't gonna cut it. A couple of enterprising engineers have successfully Kickstarted a new receiver called the Piksi, which they claim is accurate down to just a few centimeters.

    GPS is a pretty remarkable technology, but there are a number of limitations to the way your position is calculated. First of all, the bit length of a GPS code is about 300 meters, which means that even with signal from four satellites your position can only be calculated to within a few meters—at best. Furthermore, the ionosphere introduces delay into the signal, which increases error.

    The Piksi mitigates these problems and improves accuracy and precision in two ways. In addition to measuring the GPS code beamed down by satellites, it also measures the phase of the 19 centimeter wavelength of signal the code is carried on. Using a little algorithmic processing, the Piksi can use this information to improve location accuracy. Furthermore, the Piksi system uses an additional receiver as a reference point to help mitigate the effect of the ionospheric delay.

    Individual units during the Kickstarter campaign cost $500, compared to the expected $900 price once the product goes into production. This unit sure isn't cheap by traditional standards, but considering a comparable product for professional applications usually costs many thousands of dollars, it's relatively reasonable. Plus, if you're flying a couple of grand worth of drone up in the air, it's probably worth knowing EXACTLY where your money is flying—lest all that cash fly away.