*4.2. Experiment on ALOS Data*

### 4.2.1. Data Description

PRISM, the primary sensor carried by ALOS, was designed to obtain a high-resolution digital surface model to derive orthoimages on a global scale. PRISM has three panchromatic linear array push-broom sensors (forward, nadir, and backward) with a 2.5 m spatial resolution and a width of 35 km swaths. The raw image data of PRISM was observed on 20 August 2006 and covered 50 scenes; these were used as the experimental data. To verify the performances of the two methods regarding the estimation of short-period components, one scene from the experimental data was used as the typical scene, as shown in Figure 8. We extracted 100 evenly distributed GCPs as inputs for the two methods and 50 evenly distributed RCPs to evaluate the calibration performances of the two methods in this typical scene. Also, we randomly chose 20 scenes with 30 evenly distributed GCPs as the measurement data from the rest of the experimental data.

**Figure 8.** Image data of a typical scene.
