In the four+ decades since Landsat 1 launched, the spectral bands of the Landsat satellites have evolved. Landsat 9, like Landsat 8, has the most evolved of the Landsat spectral bands.

In 1972, Landsat 1 launched with a three-band Return Beam Vidicon camera system and a secondary four-band digital Multispectral Scanner System (MSS). The MSS with its scanning mirror whisking back and forth to create an image, seemed to many researchers of the period the antithesis of the high quality camera systems traditionally used in aerial studies. But the secondary MSS instrument proved itself the imaging powerhouse producing superior data. But the four-band MSS was spectrally coarse; it essentially mimicked the color infrared films that became widely used during WWII.

For follow-on sensors, Landsat management brought together scientists from diverse fields to discuss and recommend spectral channels most useful for answering questions in their research areas. These discussions informed the more sophisticated Thematic Mapper (TM) sensor with its seven spectral bands that flew on Landsats 4 and 5. The Landsat TM band placement has subsequently guided all successive Landsat sensors and is is also echoed in almost all modern passive remote sensing systems—domestic, international, public, commercial, and even those circling about other planets.

Today, Landsats 8 has and Landsat 9 will have eleven spectral bands acquired by the OLI/TIRS and OLI-2 / TIRS-2 instruments, respectively.

Landsat Bands

The Multispectral Scanner System (MSS) aboard Landsats 1–5 had four bands. The Thematic Mapper (TM) aboard Landsats 4 & 5 had seven bands. Landsat 7’s Enhanced Thematic Mapper Plus (ETM+) has 8 bands and Landsats 8 & 9 have 11 bands. The atmospheric transmission values for this graphic were calculated using MODTRAN for a summertime mid-latitude hazy atmosphere (circa 5 km visibility).

 
 

Designed to See More: Two New Bands, and a Split Thermal Band

Landsat 9, like Landsat 8, is designed to simultaneously image four visible spectral bands, one near-infrared spectral band, three shortwave-infrared spectral bands at 30 m (98 ft) spatial resolution, plus one panchromatic band at 15 m (49 ft) spatial resolution, and two thermal bands at 100 m (328 ft) spatial resolution.

See what the Landsat 8 bands can do… Landsat 9 will follow suit.

Landsats 8 and 9 are designed to see two additional parts of the spectrum. These new bands help scientists measure high, thin clouds and water quality.

water image
Coastal/Aerosol Band (Band 1)
This band helps scientists measure chlorophyll concentrations (ocean color) in coastal regions. Most of the chlorophyll comes from phytoplankton, tiny plant-like organisms that live in surface waters. This band is also useful for aerosol detection.
cirrus clouds
Cirrus Band (Band 9)
High, thin cirrus clouds can be hard to spot in satellite images. Both the clouds and their shadows can interfere with measurements. Landsats 8 and 9 are designed to detect these clouds by measuring light in the part of the electromagnetic spectrum where the clouds are most visible.
paluweh tirs image
Two Thermal Infrared Bands (Bands 10 & 11)

Everything on Earth emits thermal infrared radiation. The amount of emitted radiation depends on the object’s temperature. Landsat 9, like Landsat 8, will image data for two distinct thermal infrared spectral regions. The stray light issues that have plagued Landsat 8 will be corrected on Landsat 9.

 
 

Dwell on This

Wickiup OLI
Wickiup ETM

Landsat 8 and Landsat 9’s innovative design make them more sensitive and more reliable than earlier Landsat satellites. Their pushbroom architecture gives the satellites more dwell time over the ground, which leads to a better signal-to-noise ratio. That means you can see (and computers can detect) more nuanced details in the images.

The slider image comparison on the right shows a subsection a Landsat 8 OLI image (left) and a Landsat 7 Enhanced Thematic Mapper Plus (ETM+) acquired on same day during an underflight conducted as Landsat 8 made its way up to its nominal orbit. To achieve greater sensitivity to brightness and color, the OLI instruments on Landsats 8 and 9 (as well as the Thermal Infrared Sensors) are designed to produce 12-bit data.

The previous generation sensor, ETM+, supports 8-bit data products, which means means the brightest to the darkest pixels are discriminated with 256 data values. The greater sensitivity of OLI, OLI-2, TIRS, and TIRS-2 instruments allow the signal to be discriminated over 4096 data values, and the range has been increased to prevent saturation of very bright targets such as snow.

The practical effect of this refinement is apparent when comparing the OLI and ETM+ of Wickiup Reservoir Cascade Mountains of the Pacific Northwest: OLI shows more nuanced details in the shoreline and marshlands of the shallow Wickiup Reservoir, while at the same time showing more contrast in the snow and ice of Davis Mountain.