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Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0
From: |
Hal Murray |
Subject: |
Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0 |
Date: |
Fri, 22 Jul 2016 17:45:03 -0700 |
address@hidden said:
> Spherical distances are tricky, and ISTR that GPSD switched distance
> algorithms at one point. You almost certainly don't want the simple
> spherical law-of-cosines formula, since that has awful numerical
> sensitivities for short distances.
I'd expect distances for nearby points would be simple.
I'm assuming you start with LAT/LON. Subtract LAT and LON. LAT converts to
feet/meters by diameter of the Earth. LON is similar but gets scaled by cos
of LAT.
--
These are my opinions. I hate spam.
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, (continued)
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Fred Wright, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Hal Murray, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Gary E. Miller, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Hal Murray, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Fred Wright, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Gary E. Miller, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Fred Wright, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Gary E. Miller, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Fred Wright, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Gary E. Miller, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0,
Hal Murray <=
- Re: [gpsd-dev] several messages, Fred Wright, 2016/07/22
- Re: [gpsd-dev] several messages, Greg Troxel, 2016/07/23
- Re: [gpsd-dev] CEP(50) 0.285 meters, Fred Wright, 2016/07/23
- Re: [gpsd-dev] CEP(50) 0.285 meters, Fred Wright, 2016/07/23
- Re: [gpsd-dev] ✘CEP(50) 0.285 meters, Gary E. Miller, 2016/07/23
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Greg Troxel, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Gary E. Miller, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Hal Murray, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Gary E. Miller, 2016/07/22
- Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0, Greg Troxel, 2016/07/22