Do u knoe that the satellite navigator consider the earth more spherical than it is?

Answer 1

Yes I did know that.

Thank you for such a fantastic and intellectual question.

Answer 2

That's somewhat true if you're talking GPS. GPS uses the WGS-84 model for the Earth. It's an oblate spheroid that does take into account the oblateness of the Earth to a certain extent.

It is true that WGS-84 isn't the most accurate model of the Earth available. It's just the most accurate model available when GPS came on line. Thanks to GPS, the WGS-84 model has become so popular and is used so often for maps, that it would be too expensive and confusing to switch to more accurate models developed over the last 20 years.

WGS-84 is a smooth oblate spheroid, while the Earth's gravity field has several perturbations in it's shape. For example, using the WGS-84 model, the highest point on the island of Diego Garcia in the Indian Ocean is around 50 meters below sea level. That obviously doesn't reflect the reality of the Earth's surface near the Indian Ocean. Still, you're comparing 50 meters to an Earth radius of around 6,378,137 meteres. Your percentage of error is around 8 ten-thousandths of a percent.

Answer 3

If you're talking about GPS, yes... latitude and longitude are spherical measurements, but the actual surface of the earth (geoid) is not spherical. A sphere best fits the mathematical model, so that's what we use for navigation. It's based on the rotational axis of the Earth, so it's accurate enough for anything we would need. I'm a surveyor and we use it to obtain sub-centimeter accuracy for relative positions.

Answer 4

Yes the Earth is an oblate spheriod but the orbits of the satellites follow the oblateness so the distance between the satellites and the earth's surface (at sea level) remain a constant.

Answer 5

Hi. Not true. Satellites speed up and slow down due to the gravity changes as it orbits the Earth.