M. Martinneira et al., STUDY OF A CONSTELLATION OF BISTATIC RADAR ALTIMETERS FOR MESOSCALE OCEAN APPLICATIONS, IEEE transactions on geoscience and remote sensing, 36(6), 1998, pp. 1898-1904
A constellation of satellite radar altimeters for mesoscale ocean appl
ications has been recommended since the beginning of this decade. Stud
ies show that eight monostatic satellites are needed to achieve an ide
al sample spacing of seven days revisit time and 50-km spatial samplin
g. However, for this number of satellites the required cost of such a
constellation is very high. With the appearance of Global Navigation S
atellite Systems (GNSS), such as GPS and GLONASS, there is a great opp
ortunity for constellations of small satellites to operate in a cooper
ative bistatic way, i.e., with their sensors synchronized both in time
and space. The benefits of this concept are the subject of this paper
. In this article, we study a constellation of bistatic altimeters wit
h fewer satellites than the monostatic constellation but with the same
sampling performance. This paper first introduces the mesoscale ocean
requirements. The configuration of the bistatic constellation follows
together with an analysis of its coverage and required pulse-limited
footprints. Suitable gate lengths, pulse repetition frequency, synchro
nization, pointing requirements, and link budget are discussed, The tr
acker and estimation process are also described as well as calibration
issues. The goal of the whole design of the altimeter instrument itse
lf has been to achieve simultaneous monostatic and bistatic operation
with the simplest architecture.