MPH Issue Revisited

[freserf]

As long as you have DGPS, the accuracy is centimeters ... most handheld GPS don't have that capability ... I had to modify mine with a DGPS antenna when I was first learning about them. Basically you have close enough to hurt someone using only the satellites ... adding the D, gives you coordinate correction based on a physical location on earth. This gets you close enough to vaporize your target. I was involved in marking locations at a shipping port so we could keep track of the location of each container. Took a while to get the data, but very much improved the location checkers job.

[porschefan76]

Originally Posted by freserf

As long as you have DGPS, the accuracy is centimeters ... most handheld GPS don't have that capability ... I had to modify mine with a DGPS antenna when I was first learning about them. Basically you have close enough to hurt someone using only the satellites ... adding the D, gives you coordinate correction based on a physical location on earth. This gets you close enough to vaporize your target. I was involved in marking locations at a shipping port so we could keep track of the location of each container. Took a while to get the data, but very much improved the location checkers job.

Hi freserf, so I'm just trying to understand, are you trying to theorize a more accurate approach to operating an odometer than what the 986 uses?

The 986 literally uses a sensor that counts rotations and multiplies that by a constant, some statistically validated constant, that attempts to account for the variable diameter of all possible tires offered on the vehicle. It is not complex at all. Most other vehicles also use this method.

[BYprodriver]

Originally Posted by freserf

As long as you have DGPS, the accuracy is centimeters ... most handheld GPS don't have that capability ... I had to modify mine with a DGPS antenna when I was first learning about them. Basically you have close enough to hurt someone using only the satellites ... adding the D, gives you coordinate correction based on a physical location on earth. This gets you close enough to vaporize your target. I was involved in marking locations at a shipping port so we could keep track of the location of each container. Took a while to get the data, but very much improved the location checkers job.

My Dad was able to see the Cuban's building a missile launch site in Oct.1962 using aerial photography.

[blue62]

Originally Posted by freserf

As long as you have DGPS, the accuracy is centimeters ... most handheld GPS don't have that capability ... I had to modify mine with a DGPS antenna when I was first learning about them. Basically you have close enough to hurt someone using only the satellites ... adding the D, gives you coordinate correction based on a physical location on earth. This gets you close enough to vaporize your target. I was involved in marking locations at a shipping port so we could keep track of the location of each container. Took a while to get the data, but very much improved the location checkers job.

The point of my original post is that people are using hand held GPS to verify the accuracy of the speedometer on their cars. When most likely the GPS has a greater error factor then their speedometer. That is why I said a better way to verify the accuracy of a speedometer would be to use time over a measured distance.