Question

Differences in ocean-surface height can be measured by _____.\

Answer 1

The answer that best fits the blank is the word SATELLITES. It is the satellites that are used to determine the measurement of the ocean-surface height differences. This is used in Ocean Surface Topography wherein the sea surface is affected by both ocean circulation and gravity. 

Answer 2

Answer;

Satellite

Differences in ocean-surface height can be measured by Satellite

Explanation;

• The topography of the ocean or the height of the ocean surface relative to a level of no motion provides the information on tides, and the distribution of heat and mass in the Earths's oceans.
• The ocean topography is measured using satellites altimeter. Satellites use radar altimeters that are specially made to measure the height of the ocean surface.  The satellites measure the height of the ocean surface with an accuracy of 3 cm relative to the center of the earth.
• Satellite altimeter combines precise orbit determination with accurate ranging by a microwave altimeter of ocean distance to the satellite.