我正在为 Android 编写一个玩具汽车导航应用程序，主要是为了学习 Android SDK。
在测试我的应用程序时，它在几个小时内运行良好。然后，突然，它报告我的位置是在我真实位置以南 100 公里的一个城镇，以 300 公里/小时的速度行驶。事实上我的行驶速度约为 120 公里/小时。
我将应用程序更改为谷歌地图，它也显示了相同的错误位置和近似速度。由于我当时正在车流中高速行驶，为了安全，我决定不再摆弄手机，直接收了起来。下次我拿起它时（大约 15 分钟后），位置和速度再次正确。
我将向我的程序添加诊断，以显示报告的 GPS 修复的准确性。
我有几个问题：
- 这是 Android 手机的硬件/固件问题吗？ （我有 HTC Hero）
- 这是 GPS 接收器的已知故障模式吗？
- 是什么导致 GPS 接收器报告的位置如此不准确？
- 我车里还有另一个 GPS 接收器（Garmin 汽车导航仪）。该接收器是否会干扰 HTC Hero 设备？
I'm writing a toy car-navigation app for Android, mostly to learn the Android SDK.
While testing my application, it worked fine for a few hours. Then, suddenly, it reported my position as being in a town 100km south of my real position, travelling at 300km/h. I was in fact travelling at approximately 120km/h.
I changed application to Google Maps, and it also showed the same erroneous position and approximate velocity. Since I was driving a car in dense traffic at high speed, for safety, I decided not to start fiddling with the phone any more, and just put it away. The next time I took it up (maybe 15 minutes later), the position and velocity was correct again.
I will add diagnostics to my program to show the reported accuracy of the GPS-fix.
I have a few questions:
- Is this a hardware/firmware problem in android phones? (I have a HTC Hero)
- Is this a known failure mode of GPS-receivers?
- What could make the GPS-receiver report such inaccurate positions?
- I had another GPS receiver in the car (a Garmin car navigator). Could this receiver have interferred with the HTC Hero unit?
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手持式 GPS 设备的准确度远低于通常声称的准确度，但偏离 100 公里（或博尔顿和马德里之间的任何距离）是相当不寻常的。听起来 GPS 系统可能短暂地发生了一些奇怪的事情。
您汽车中的其他 GPS 接收器不会造成这种情况 - 设备天线仅接收信号，不会广播任何内容。
更新：可能是太阳耀斑。文章可笑地声称它们会产生 30 米范围内的误差；这是可笑的，因为 GPS 设备的精确度低于正常条件下的精度。
Handheld GPS devices are much less accurate than is typically claimed, but being off by 100 km (or by whatever the distance is between Bolton and Madrid) is pretty spectacularly unusual. It sounds like something weird may have briefly happened to the GPS system.
The other GPS receiver in your car would not have caused this - the device antenna just receives signals, it doesn't broadcast anything.
Update: might be solar flares. The article laughably claims they'll produce errors in the range of 30 meters; it's laughable because GPS devices are less accurate than that under normal conditions.
由于 GPS 和卫星锁定的性质，在我看来，您的数字低于所需的数字，然后退回到其他某种方法，即基于蜂窝塔的猜测位置的方法……
在华盛顿，我有时会看到这种情况在火车上旅行，因为当我进入隧道时 GPS 信号丢失，并且基于“塔”的位置开始发挥作用。
我唯一能想到的就是对您的位置进行某种地理距离推理...但我不知道一旦你知道你的地理数据不好你会做什么。 :-)
Due to the nature of GPS and satellite locking, it just sounds to me like you dropped below the required number, and fell back to some other method, cell-tower-based method of guessing location...
In DC I see this sometimes when traveling on the train due to the fact that the GPS is loosing signal when I go into the tunnels and the "tower" based location kicks in.
The only thing I can think of is to do some sort of geo-distance reasoning about your position... but what you would do once you knew you had bad geo data I don't know. :-)