Inally, high-resolution sensors are defined as these with a couple of meters resolution, which include

Inally, high-resolution sensors are defined as these with a couple of meters resolution, which include 3 m or less. IKONOS-2 belongs to this category and may be located in a number of research of benthic habitat mapping [869], but mainly before 2015, the year it has ceased operating. Combretastatin A-1 supplier GaoFen-2 satellite, launched in 2014, has precisely the same spatial and spectral resolution as IKONOS-2, but just isn’t as widely applied [90], perhaps for the reason that of its age: it was launched in 2014, when some sensors currently had a far better resolution. GaoFen have distinctive satellites (from GaoFen-1 to GaoFen-14) that have the same or perhaps a reduce resolution than GaoFen-2. Using a similar sensor plus a slightly far better resolution than IKONOS-2, the Quickbird-2 satellite gives pictures for quite a few studies of reef mapping [58,916]. Please note that the Quickbird-2 system was stopped in 2015. Comparable characteristics are proposed by the Pleiades-1 satellites, from the Optical and Radar Federated Earth Observation system, also present within the literature [97,98]. An even greater accuracy may be identified with GeoEye-1 satellite,Remote Sens. 2021, 13,six ofproviding photos at a resolution of much less than 1m, making it especially helpful to study coral reefs [99]. Probably the most frequent and most precise satellite photos come from WorldView satellites. For instance, WorldView-2 (WV-2), launched in 2009, has been widely applied for benthic habitat mapping and coastline extraction [40,76,90,10007]. Despite the high-resolution images supplied by WV-2, the highest top quality pictures accessible in the current time come from WorldView-3 (WV-3), launched in 2014 [39,10810]. WV-3 includes a total of 16 spectral bands and is hence able to compete with hyperspectral sensors with more than a hundred bands (for instance Hyperion). Furthermore, its spatial resolution may be the highest offered amongst current satellites, and is even comparable to regional measurement procedures for example Unmanned Airborne Autos (UAV) [111]. Amongst all of the spectral bands presented by the WV-3 sensors, the coastal blue band (40050 nm) is specifically valuable for bathymetry, as this wavelength penetrates water much more quickly and might aid to discriminate seagrass patterns [112]. Even though the raw SWIR resolution is reduced than the 1 accomplished in visible and near-infrared bands, it could be additional processed to create high-resolution SWIR photos [113]. Also, the WV-3 panchromatic resolution is 0.3 m, which practically reaches the standard size of coral reef components (0.25 m), as a result creating it also valuable for reef monitoring [114]. To additional evaluate the significance of each and every satellite in the global literature (not simply on coral research) and to detect Tasisulam sodium trends in their use, we searched in Scopus and analyzed the number of articles in which they appear among 2010 and 2020. Many trends may be noticed. Very first, amongst low-resolution satellites, it appears that although the usage of Landsat remains steady over the year, the usage of Sentinel has exploded (by a multiplication element of 20 in between the period 2014014 and 2018020). With regards to high-resolution satellites, we detect trends in their usage: within the period 2010014, Quickbird and IKONOS satellites have been predominant, but their usage decreased by greater than 85 throughout the years 2018020. However, the amount of papers published employing WorldView and PlanetScope has been growing: respectively from 108 and 0 in 2010014, to 271 and 164 in 2018020. The full numbers for every single satellite might be identified in Figure A1. Figure 3 depicts which satellites were employed in th.