Revision History for FS 2024-3005 U.S. Geological Survey Landsat Next ----------------------------------------------------- Posted online March 11, 2024 ----------------------------------------------------- Revised and reposted March 25, 2024, version 1.1 On p. 1, in the first paragraph, text was changed from "is planned for launch in 2030" to "is targeted for launch in the early 2030s." The end of the first paragraph was revised to include "surface waters, and coastal regions." In the second paragraph, text was changed from "With three satellites in a Sun-synchronous orbit at an altitude of 653 kilometers (406 miles), the Landsat Next "triplets" will provide higher spatial resolution observations on a new global grid system called the Worldwide Reference System-3. The satellites can make more frequent observations using this triplet constellation formulation, which has a 6-day revisit cycle of any location on Earth's land and coastal regions (fig. 1). This temporal revisit capability is much more frequent than the current 16-day repeat cycle of both Landsat 8 and Landsat 9." to "With three satellites in a Sun-synchronous orbit at an altitude of 653 kilometers (406 miles), the Landsat Next "triplets" will provide higher spatial resolution observations on a new global notation system called the Worldwide Reference System-3. The satellites can acquire frequent observations using this triplet constellation observational concept, which has a 6-day revisit cycle of any location on Earth's land and coastal regions (fig. 1). The frequency of this temporal revisit capability surpasses the 16-day repeat cycle of Landsat 8 or Landsat 9 individually and the combined 8-day repeat cycle of both satellites." In the third paragraph, text was changed from "Coupled with an increase in the number of revisit times" to "Coupled with an increase in the number of imaging revisit times" and from "making it easier to characterize Earth's land surfaces, surface waters" to "making it easier to characterize Earth's land surfaces, water bodies." In the "Landsat Next Facts" box, the observatory orbital separation value was changed from 20 to 120 degrees. The final entry in the box (Planned launch: 2030) was deleted. Figure 2 was replaced with a newer graph. The caption for figure 2 was changed from "The pixel resolution, in meters, and estimated spectral band passes for the sensors on all Landsat satellites." to "The estimated spectral bandpasses and pixel resolution (right axis) for the sensors on all Landsat satellites." On p. 2, the title for table 1 was changed from "Landsat Next band numbers and names, pixel resolution, wavelength, and band width." to "Landsat Next spectral band numbers and names, pixel resolution, wavelength range, and observational rationale." The headings in table 1 were changed from "Band number/name" to "Spectral band number/name," from "Wavelength (nm)" to "Wavelength range (nm)," and from "Rationale" to "Observational rationale." The first heading was changed from "Continuity of Multispectral Capability" to "Observational Continuity." In that section, text was changed from "Each Landsat Next Instrument Suite will image the Earth across 26 spectral bands. These bands will include refined versions of Landsat 8 and Landsat 9 heritage bands, 5 bands with similar spatial and spectral characteristics to Europe's Copernicus Sentinel-2 satellites to allow easier merging of joint data products, and 10 new spectral bands to support emerging Earth surface change applications such as algal bloom detection, ice sheet monitoring, crop soil conservation, and surface emissivity estimation (table 1; fig. 2)." to "Each Landsat Next observatory will image the Earth across 26 spectral bands. These spectral bands will include Landsat 8 and Landsat 9 heritage bands, 5 bands with similar spatial and spectral characteristics to Europe's Copernicus Sentinel-2 satellites to allow easier joint use of data products, and 10 new spectral bands to support emerging Earth surface change applications such as algal bloom detection, snow and ice sheet hydrology, crop soil conservation, and surface emissivity estimation (table 1; fig. 2)." In the next section, text was changed from "The sharpened spatial resolution, new spectral bands, and increased observations of Landsat Next will transform the ability to monitor and forecast landscape change. New and improved technologies have the capability to enable research and public services for fire monitoring and recovery, water resources management, agriculture development and evapotranspiration, ecosystem health, public health, and urban growth/suburban spawl. Landsat Next will greatly augment the program's more than five-decade data record, which has proven valuable for resource management, environmental sustainability, and climate resiliency." to "The sharpened spatial resolution, new spectral bands, and increased observational frequency of Landsat Next will transform the ability to monitor and forecast landscape change. New and improved sensor technologies have the capability to enable research and public services for fire monitoring and recovery, water resources management, agriculture development and evapotranspiration, ecosystem health, public health, and urban sprawl. Landsat Next will greatly augment the joint U.S. Geological Survey/National Aeronautics and Space Administration Landsat program's more than five-decade data record, which has proven valuable for resource management, environmental sustainability, and climate resiliency." At the bottom of p. 2, a hyperlink was modified from https://www.usgs.gov/programs/national-land-imaging-program to https://www.usgs.gov/nli. The caption for the background image was changed from "Acquired by Landsat 8 in 2017, image shows part of Lake Erie during a harmful algal bloom event. Landsat Next's super spectral bands will improve the accuracy of monitoring for harmful algal blooms." to "The image below was acquired by Landsat 8 on September 26, 2017 and shows western Lake Erie during a large phytoplankton bloom. Landsat Next's additional spectral bands will improve the accuracy of mapping harmful algal blooms."