During recent years the accurate measurements from the TOPEX/POSEIDON satel
lite have improved global ocean tide models considerably. However, these gl
obal ocean tide models are still not accurate enough on the continental she
lves for detailed oceanographic studies. The need for increasing accuracy i
n shelf regions calls for inclusion of more than just semidiurnal and diurn
al constituents in future global ocean tide models. This is because a consi
derable part of the tidal variability on the shelves is caused by shallow w
ater constituents. One example is the M-4 constituent, which exceeds 50 cm
at several locations on the northwest European shelf. So far, TOPEX/POSEIDO
N has not been considered for resolving these constituents, mainly owing to
its coarse ground track resolution. Reliable empirical estimates of severa
l major shallow water constituents can be obtained from TOPEX/POSEIDON by c
ombining along-track and crossover observations. Estimates of the major sha
llow water constituents for the northwest European shelf, M-4, M-6, and MS4
, are presented in this study and compared with tide gauges and existing hy
drodynamic models.