ERS-1 for mapping jetties effects on shoreline change Results and Discussion Fig. 1a shows that the wave peaks propagated from southeast direction. When the wave spectra approached the jetties, the wave spectra turn to propagate towards the southwest direction and tend to diffract along the jetties. The wavelength along the jetties ranged from 25 m to 100 m (Fig. 1b). It obvious that the wavelength decreased when the wave spectra changed their directions (Fig. 1b). Fig. 2 shows that the wave orthogonal tended to curve along the jetties. The wavelength decreased near the jetties and inside the port. This indicates that the wave diffraction patterns. A similar finding is in Fig. 1. The wave spectra energy along the diffraction orthogonal have a maximum peaks of 0.6 m2 s (Fig. 3). The wave spectra peaks are shifted in azimuth direction due to the effect of Doppler shift frequency Vachon et al., [8] . Fig. 4 shows that the longshore current vectors moved with velocity ranged from 0.4 m/s to 1.3 m/s towards the northwest direction. The maximum velocity was observed in the south jetty while the minimum velocity was observed in the north jetty. This means that the jetty could reduce the longshore current velocity. The longshore current curved inside the port and moved out the port with minimum velocity towards the north of Chendering.  Fig.1 (a) Wave spectra Modeled from ERS-1 data (b) Wave spectra Direction and Length  Fig. 2. Wave Diffraction pattern along Port Chendering  Fig. 3. Spectra Energy of Wave Diffraction  Fig. 4. Longshore Current Modeled from Wave Spectra Derived from Quasi- linear Model |