Table 1 Airborne laser scanning (ALS) datasets and acquisition parameters used in previous studies
Yu et al. (2004) | Yu et al. (2006) | Hopkinson et al. (2008) | Vepakomma et al. (2008) | Vepakomma et al. (2010) | Song et al. (2016) | Næsset and Gobakken (2005) | Ma et al. (2018) | |
|---|---|---|---|---|---|---|---|---|
Sensor | TopoSys-1 | Toposys-1 Toposys-2 | ALTM sensor 1225 to 3100 | ALTM1020 ALTM 2050 ALTM 3100 | ALTM 1020 ALTM 2050 | ALTM2050 Riegl LMS-Q560 | ALTM 1210 | Optech GEMINI |
Dates | Sept. 1988 June 2000 | Sept. 1988 May 2003 | Sept 2000 July 2002 Nov. 2004 Dec. 2005 | June 1998 Aug. 2003 July 2007 | June 1998 Aug. 2003 | Oct. 2004 Aug. 2008 Aug. 2010 | June 1999 July 2001 | 2007–2008 2012–2013 |
Altitude (m) | 400 | 400 | 800 to 1000 | 700 to 1000 | 700 1000 | 1000 300 | 700 850 | 600–800 |
Laser pulse frequency (kHz) | 83 | 83 | 25 to 50 | 5 50 67 | 4 50 | 50 150 | 10 10 | 100 |
Scan frequency (Hz) | / | 653 | 30 to 44 | / | / | 67 80 | 21 30 | 40–60 |
Scan angle (°) | ± 7.1 | ± 7.1 | ± 12 to ± 18 | / | ± 10 ± 15 | ± 5.3 ± 30 | ± 17 ± 16 | ± 12– ± 14 |
Density | 10 pulses/m2 | 10 pulses/m2 | 2.5 to 3.6 returns/m2 | 0.33 to 10 hits/m2 | 0.3 3 hits/m2 | 11.3 51.8 returns/m2 | 1.18 0.87 pulses/m2 | 10 points/m2 |