Arctic sea surface height maps from multi-altimeter combination.

2.3.2 Along-track filtering and subsampling Before the optimal interpolation open ocean along-track SL anomaly measurements are filtered and sub-sampled to reach a 5 HT <math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><mrow class="unit"><mi mathvariant="normal">Hz</mi></mrow></math> ht resolution. Polar regions are observed up to 88 HT <math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi /><mo> </mo></msup></math> ht thanks to its 92 HT <math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi /><mo> </mo></msup></math> ht orbit inclination. Monthly sea level anomaly (SLA) fields are available on a 0.25 HT <math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi /><mo> </mo></msup></math> ht latitude by 0.5 HT <math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi /><mo> </mo></msup></math> ht longitude grid. [3] processed Envisat and CryoSat-2 data to produce monthly dynamic ocean topography estimates from 2003 to 2014 on a 0.5 HT <math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi /><mo> </mo></msup></math> ht latitude by 0.75 HT <math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi /><mo> </mo></msup></math> ht longitude grid. [Extracted from the article]