Table 1 Data acquisition and camera specifications
| Â | Block A | Block B | Block C |
|---|---|---|---|
Acquisition date | June 2012 | June 2013 | July 2013 |
GSD (cm) | 20 | 20 | 20 |
Nominal overlap | 60%/30% | 60%/30% | 60%/30% |
Spectral resolution | R, G, B, NIR | R, G, B, NIR | R, G, B, NIR |
Camera | UltraCam-Xp | UltraCam Eagle | UltraCam-Xp |
 Focal length (mm) | 100.5 | 79.8 | 100.5 |
 Sensor size (mm) | 67.860 × 103.860 | 68.016 × 104.052 | 67.860 × 103.860 |
 Pixel size (μm) | 6.0 × 6.0 | 5.2 × 5.2 | 6.0 × 6.0 |