Thanks to the drifting nature of the ground track of Jason-1 during its geodetic mission (Jason-1 GM), there are 1200 overlap events where both altimeters are measuring the ocean topography on the same track (less than 10 km from one another, i.e. the altimeter footprint radius) over an entire pass, i.e. tens of thousands of kilometres.

This paper reports the first statistical analysis of this dataset with variance maps, spectra, auto-correlation and space / time scales that are consistent with past observations. Our results highlights the value of this Jason-1 GM overlap dataset for more sophisticated studies of the rapid ocean variability, but also two major limitations: 1/ the noise level of Jason-class altimeters prevents from analyzing scales smaller than 80 km, and 2/ short time differences also absorb a fraction of the derivative of slower signals.