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The Landsat 8 and Landsat 9 satellites follow the Worldwide Reference System-2 (WRS-2) and together acquire nearly 1,600 scenes each day. Level-1 products created from newly acquired data become available for download within 6 hours of acquisition.
The USGS Landsat Multi-Satellite Operations Center (LMOC) oversees and ensures the acquisitions are successful and manages any anomalies that may arise.
After the launch of Landsat 1 in 1972, nations around the world utilized the Landsat data, but there was no conventional labeling system for how scenes were acquired. To catalog Landsat imagery collected over Canada, the Canada Centre for Remote Sensing (CCRS) created a series of grid paths across their country drawn parallel to latitude lines. The USGS later adopted this schema, and extended the reference to the entire surface of the planet. This grid reference system became known as the Worldwide Reference System (WRS-1). After the expansion, the WRS-1 grid included 251 paths and 119 rows, where each intersection of a path and a row denotes the nominal center of a Landsat scene. This reference system provided an 18-day repeat cycle for the Landsat 1, Landsat 2, and Landsat 3 satellites.
Since the launch of Landsat 4 in 1982, the Worldwide Reference System-2 (WRS-2) has been in use. The WRS-2 grid has 233 paths and 123 rows, with a 16-day repeat cycle per satellite. The Landsat 8 and Landsat 9 satellites have an 8-day offset.
Long Term Acquisition Plans
Landsat 8 and Landsat 9 acquire imagery directed by the Long Term Acquisition Plan (LTAP) established for each satellite. Each LTAP utilizes parameters such as seasonality, land definition, historical cloud cover, gain settings, and sun angle to determine the daily acquisition schedule. Nearly all day-lit imaging opportunities are scheduled for both satellites. Day-lit images are defined as images with sun elevations greater than five degrees.
Every day, the LMOC assigns a priority to each Landsat 8 and Landsat 9 scene scheduled to be acquired (collectively known as the day’s candidate scenes), based on each satellite’s LTAP priority assignments. These assignments help optimize acquisitions by taking into account the scheduled acquisitions, as well as any special requests that may be received from the user community.
The LTAPs direct that the following acquisitions be made:
Over 99 percent of descending day-lit land images between 57 degrees North (Row 21) and 57 degrees South (Row 104) latitudes where the side lap between paths is less than 50 percent.
Over 91 percent of the descending day-lit land images beyond 57 degrees with decreasing priority inversely proportional to the amount of side lap between paths.
Over 99 percent of open water scenes, such as the Mediterranean, Baltic, and Caribbean Seas, that complete land intervals and reefs.
Nighttime, open ocean, and ascending scenes are only acquired by special request. The success rate is a function of priority and cloud cover thresholds assigned. Over 95 percent of special request images submitted are approved and are acquired.
The map below shows the geographic coverage of acquisition priorities for Landsat 8 and Landsat 9 on a typical day. Lower priority scenes (shown as purple and red) are more likely to be rejected to meet the daily limit, while the highest priority scenes (shown in green, yellow, and orange) are only rejected for spacecraft maneuvers or rare calibration events.
An example of the geographic coverage of Landsat acquisition priorities.
Special Requests for Future Landsat Acquisitions
Special requests can be made for the acquisition of Landsat 8 or Landsat 9 scenes that do not fall within the candidate images acquired by the logic defined in the information described above. Special requests are only needed to acquire night, low sun elevation, ocean, and ascending day-lit data, or for emergency response operations. All attempts will be made to accommodate emergency requests over other high priority activities. However, most activities, such as spacecraft maneuvers, are required and cannot be changed to acquire data.
When you submit your requests, you will be notified when they are received. After review, you will receive another email notifying you if your request was denied or approved.
Landsat 7 Acquisitions
NOTE: The information in this section is for historical reference only.
After Landsat 8 launched in 2013, Landsat 7 started to acquire data based on a continental acquisition strategy, in which data over Antarctica, oceanic islands, Greenland, and Row 9 and above were no longer acquired systematically.
Starting April 6, 2022, Landsat 7 acquisitions were suspended to allow for a series of spacecraft burns to lower the satellite’s orbit by 8 kilometers (km) (learn more about this activity). After a series of maneuvers lowered the satellite out of the standard 705km WRS-2 orbit, Landsat 7 imaging resumed on May 5, 2022 at a lower orbit of 697 km. The USGS elected to continue science data acquisition from the Enhanced Thematic Mapper Plus (ETM+) to assess the utility of imagery collected at the new lower orbit and earlier equatorial crossing time. Initially, it was decided to collect data through September 2022 to capture the Northern Hemisphere growing season. However, since the health of the satellite and the ETM+ sensor remained steady, and the quality of the data remained nominal, data acquisitions continued until January 2024.
On January 19, 2024, Landsat 7 imaging was suspended due to the satellite’s transition into full sunlight, which caused issues with the batteries. Imaging was suspended to retain the health and safety of the batteries. Visit the January 19th News page describes more about how being in full sunlight affects the satellite, and why data imaging was suspended.
Landsat Maneuvers
In order to maintain a consistent equatorial crossing time, the Landsat spacecrafts must occasionally undergo maneuvers using the satellite's propulsion subsystem to fire thrusters and bring about a change in the orbital elements. When maneuvers are executed, science imaging may be briefly suspended. Please see the Landsat 8 & 9 maneuver webpage and the Landsat 7 maneuver webpage for additional information.