Landsat 9 and How It Compares to Other Landsat Missions

(Landsat Missions, 2023).

Landsat 9 Sensors

The Landsat 9 satellite replaces the Landsat 7 satellite and “has a design very similar to Landsat 8” (NASA, 2022). Landsat 9 hosts the “Operational Land Imager (OLI)” and the “Thermal Infrared Sensor (TIRS),” both expected to last five years (USGS, 2022).

Landsat 9 Spatial Resolution and Comparison to Other Landsat Missions

Landsat 9 and its accompanying sensors and bands have varying spatial resolutions. Landsat 9’s OLI sensor, containing bands 1-9, has a spatial resolution of 30 meters, except the panchromatic band 8, which has a spatial resolution of 15 meters (NASA, 2022). Landsat 9’s TIRS sensor, containing bands 10 and 11, has a spatial resolution of 100 meters.

Landsat 9’s spatial resolutions show a stark improvement over previous Landsat missions. Landsat 1-5 have spatial resolutions of 60 meters for each band (USGS, n.d.). Landsat 4-5 improved upon predecessors with a 30-meter resolution for all seven bands except for band 6 with a spatial resolution of “120 meters, but is resampled to 30-meter pixels” (USGS, n.d.). Landsat 7’s spatial resolution for bands 1-5 and 7 is 30 meters, akin to Landsat 4-5. However, band 6 has a spatial resolution of 60 meters and is resampled to 30 meters. Band 8 has a spatial resolution of 15 meters. Landsat 8 has a spatial resolution identical to Landsat 9.

Landsat 9 Spectral Resolution and Comparison to Other Landsat Missions

Landsat 9 contains OLI and TIRS sensors which are “improved replicas of those onboard Landsat 8” (USGS, 2022). The OLI sensor aboard Landsat 9 contains bands for the “visible, near-infrared, and shortwave-infrared bands,” all using higher radiometric precision than previous Landsat missions (USGS, 2022). The increased radiometric precision enables “sensors to detect more subtle differences, especially over darker areas such as water or dense forests” (USGS, 2022). The TIRS sensor onboard Landsat 9 is an improved version of those onboard previous missions and “measures the thermal infrared radiation, or heat, of the Earth’s surface with two bands” (USGS, 2022).

The bands, wavelengths, and resolutions are as follows:

(USGS, 2022).

Landsat 1-3 contained four bands numbered 4 through 7, containing wavelengths ranging from the visible to the near-infrared (Landsat Missions, n.d., USGS, 2018a). Landsat 4-5 contained seven bands numbered 1 through 7, with wavelengths covering the visible, near-infrared, short-wave, and thermal infrared (USGS, n.d., USGS, 2018b). Landsat 7 contained eight bands numbered 1 through 8, containing wavelengths ranging from visible, near-infrared, short-wave infrared, thermal infrared, and the additional panchromatic band. Landsat 8 contains the same bands as Landsat 9, numbered 1 through 11 (USGS, n.d.). Landsat 8’s 11 bands contain wavelengths ranging from coastal aerosol, visible, near-infrared, short-wave infrared, panchromatic, cirrus, TIRS 1, and TIRS 2 (USGS, 2018b).

Landsat 9 Temporal Resolution and Comparison to Other Landsat Missions

Landsat 9 has a temporal resolution of 16 days, acquiring “as many as 750 scenes per day” (USGS, 2022). The variation between the temporal resolutions of Landsat 9 and Landsat 8’s is eight days (NASA, 2022). The combination of Landsat 8 and 9 simultaneously imaging Earth created a joint temporal resolution of eight days. “Landsat 9, like Landsat 8, has a higher imaging capacity than past Landsats, allowing more valuable data to be added to the Landsat global land archive—around 1,400 scenes per day” (NASA, 2022).

Landsat 1-3 had a temporal resolution of 18 days (Landsat Missions, n.d., Landsat Missions, 2016a, Landsat Missions, 2016b). Landsat 4, 5, 6, and 7 had a 16-day temporal resolution (Landsat Missions, 2016c, Landsat Missions, 2016d, Landsat Missions, 2016e, Landsat Missions, 2016f). Landsat 8 has a 16-day temporal resolution allowing it to work in conjunction with Landsat 9 to provide a joint temporal resolution of eight days (Landsat Missions, 2016g, NASA, 2022).

References

USGS. (n.d.). What are the band designations for the Landsat Satellites? What are the band designations for the Landsat satellites? | U.S. Geological Survey. Retrieved October 15, 2022, from https://www.usgs.gov/faqs/what-are-band-designations-landsat-satellites

Landsat Missions. (n.d.). Landsat 1. Landsat 1 | U.S. Geological Survey. Retrieved October 15, 2022, from https://www.usgs.gov/landsat-missions/landsat-1

USGS. (2018b). What are the best landsat spectral bands for use in my research? What are the best Landsat spectral bands for use in my research? | U.S. Geological Survey. Retrieved October 15, 2022, from https://www.usgs.gov/faqs/what-are-best-landsat-spectral-bands-use-my-research

Landsat Missions. (2016a). Landsat 2 | U.S. Geological Survey. USGS. https://www.usgs.gov/landsat-missions/landsat-2Links to an external site.

Landsat Missions. (2016b). Landsat 3 | U.S. Geological Survey. USGS. https://www.usgs.gov/landsat-missions/landsat-3Links to an external site.

Landsat Missions. (2016c). Landsat 4 | U.S. Geological Survey. USGS. https://www.usgs.gov/landsat-missions/landsat-4Links to an external site.

Landsat Missions. (2016d). Landsat 5 | U.S. Geological Survey. https://www.usgs.gov/landsat-missions/landsat-5Links to an external site.

Landsat Missions. (2016e). Landsat 6 | U.S. Geological Survey. https://www.usgs.gov/landsat-missions/landsat-6Links to an external site.

Landsat Missions. (2016f). Landsat 7 | U.S. Geological Survey. https://www.usgs.gov/landsat-missions/landsat-7Links to an external site.

Landsat Missions. (2016g). Landsat 8 | U.S. Geological Survey. https://www.usgs.gov/landsat-missions/landsat-8Links to an external site.

NASA. (2022, March 24). Landsat 9. NASA. Retrieved October 15, 2022, from https://landsat.gsfc.nasa.gov/satellites/landsat-9/

USGS. (2018a). USGS eros archive - landsat archives - landsat 1-5 Multispectral Scanner (MSS) level-1 Data Products Active. USGS EROS Archive - Landsat Archives - Landsat 1-5 Multispectral Scanner (MSS) Level-1 Data Products | U.S. Geological Survey. Retrieved October 15, 2022, from https://www.usgs.gov/centers/eros/science/usgs-eros-archive-landsat-archives-landsat-1-5-multispectral-scanner-mss-level

USGS. (2022, August). Landsat 9. USGS. Retrieved October 15, 2022, from https://pubs.usgs.gov/fs/2019/3008/fs20193008.pdf