**Author details**

temporal correlation of 0.64 for MLE-4 and Ice-2 retrackers and 0.66 for Ice-1 retracker, and RMS error of 34 cm for all retrackers. Similar situation is shown near the Ko Taphao Noi tide gauge. The performance of three retracker are nearly similar with temporal correlation between 0.87 and 0.89 and RMS error between 8 and 12 cm. Near Vung Tau tide gauge, there is no data available for distance within 5 km from coastline. This is because, within this distance, satellite track crosses over a bay, thus producing complicated waveforms. The data over this area are unable to be retrieved from the three retracking algorithms. Near Langkawi tide gauge, the Ice-1 is the only retracker that can recover data. The temporal correlation and RMS error are 0.63 and 52 cm, respectively. Near Lubang tide gauge, Ice-2 is the optimum retracker based on the highest temporal correlation of 0.72 and RMS error 15 cm. The MLE-4 retracker seems to be the most inferior for this region, with a temporal correlation of 0.27 and an RMS error of 22 cm.

**Figure 12.** The temporal correlation and RMS error for MLE-4, Ice-1, and Ice-2 for distance within 5 km from coastline.

The AltiKa shows an excellent retracked SLA data coverage over the coastal water, with ≥85% data availability for most locations of the experimental regions (three out of five regions). AltiKa measurements also can get as close as ~1 km from the coastline. This is extremely better than the performance of previous missions (i.e., Jason-2 and Envisat), which can generally

For overall results, it shows that the Ice-1 is the optimum retracker over the Southeast Asia coastal region, with the percentage of data availability up to 90% and the minimum distance

provide measurements beyond ~7–10 km from the coastline.

**5. Summary**

58 Multi-purposeful Application of Geospatial Data

Noor Nabilah Abdullah1 and Nurul Hazrina Idris1,2\*

\*Address all correspondence to: nurulhazrina@utm.my

1 Faculty of Geoinformation and Real Estate, Universiti Teknologi Malaysia, Johor Bahru, Malaysia

2 Geoscience and Digital Earth Center, Research Institute for Sustainability and Environment, Universiti Teknologi Malaysia, Johor Bahru, Malaysia
