Sea surface height (SSH) observations from satellite altimeter are subjected to various types of environmental and geophysical errors. To get the small amplitude (of the order of a few centimeters) dynamic oceanographic signals from altimeters, effects due to these errors have to be corrected. The validity of each of the correction terms to the ERS-1 altimeter measurements have been studied. Most of the corrections reduced the variance and have thus been found to be effective altimetric corrections.