3 Bucciarelli, T. Saverio Cacopardi Picardi, G. Seu, R. Levrini, G. Renzo Perfetti 1988 International Geoscience and Remote Sensing Symposium, 1988 (IGARSS'88) Florence, Italy 2 973-976 12/09/1988 In order to extend radar altimeter operations over surfaces different from ocean, tracking algorithms able to maintain range tracking in environments such as sea ice, land, and the transitions between them were studied. Range discriminators suitable for robust range tracking are analyzed and compared from the point of view of linearity, sensitivity, and processing load. The term robust is intended in the sense of good performance in lock maintenance for the typical echo waveforms in the described scenarios. A tradeoff seems to be necessary between a wide linear dynamic range, for locking, and the complexity of the algorithm from the point of view of processing load. Noise power mean level must be removed before applying the algorithm to obtain satisfactory results with all kinds of discriminators analyzed. A digital chirp generator is likely to be used to control resolution while changing the received waveform. http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=570495