Chapter 2 Satellites - Image Collection

VICAL used the atmospherically corrected land surface reflectance images from Landsat (missions 4, 5, 7, 8 and 9, with images from 1982 to present) and Sentinel-2. Table 2.1 shows the properties of these image collections in the GEE.

Table 2.1: Image collection of Landsat and Sentinel-2 within the Google Earth Engine (GEE)

Sensor	Dataset.availability	Collection.ID
Landsat-4 TM	22/08/1982 - 24/06/1993	LANDSAT/LT04/C02/T1_L2
Landsat-5 TM	16/03/1993 – 05/05/2012	LANDSAT/LT05/C02/T1_L2
Landsat-7 ETM+	01/01/1999-present	LANDSAT/ LC08 /C02/T1_L2
Landsat-8 OLI	11/04/2013- present	LANDSAT/LE07/C02/T1_L2
Landsat-9 OLI-2	31/10/2021- present	LANDSAT/LC09/C02/T1_L2
Sentinel-2 (MSI)	28/03/2017-present	COPERNICUS/S2_SR_HARMONIZED

The location of the different spectral bands of these sensors is shown in Figure 2.1.

Figure 2.1: Comparison of Landsat and Sentinel-2 and location of the spectral bands. The numbers indicate the number of spectral bands considered in each sensor (NASA 2021)

In VICAL, there are four calculation options in VICAL with these image collections: (i) Landsat (7, 8 and 9), (ii) Sentinel-2, (iii) Landsat (7, 8 and 9) and Sentinel-2 and (iv) Landsat (4 and 5).

References

NASA. 2021. Sentinel-2A Launches—Our Compliments & Our Complements - Landsat Science Available Online. https://landsat.gsfc.nasa.gov/article/sentinel-2a-launches-our-compliments-our-complements/.