USGS EROS Archive - Landsat Archives - Landsat 7 Enhanced Thematic Mapper Plus Collection 2 Level-1 Data

Landsat 7 Enhanced Thematic Mapper Plus (ETM+) Collection 2 Level-1 15- to 30-meter multispectral data. (1999 to present)

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The Landsat Enhanced Thematic Mapper Plus (ETM+) sensor onboard the Landsat 7 satellite has acquired images of the Earth nearly continuously since April 1999, with a 16-day repeat cycle. Landsat 7 images are referenced to the Worldwide Reference System-2.

All Landsat 7 scenes collected since May 30, 2003 have data gaps due to the Scan Line Corrector (SLC) failure. Landsat 7 scenes acquired after this date are categorized as SLC-off. Landsat 7 ETM+ images consist of eight spectral bands with a spatial resolution of 30 meters for bands 1 to 7. The panchromatic band 8 has a resolution of 15 meters. All bands can collect one of two gain settings (high or low) for increased radiometric sensitivity and dynamic range, while Band 6 collects both high and low gain for all scenes. Approximate scene size is 170 km north-south by 183 km east-west (106 mi by 114 mi).

Standard Processing Parameters

All Landsat 7 ETM+ Collection 2 Level-1 data are processed using the Landsat Product Generation System (LPGS) with the following parameters applied:

Parameter
Pixel Size	30-meters
Output Format	Cloud Optimized GeoTIFF (COG)
Resampling Method	Cubic Convolution (CC)
Map Projection	UTM – WGS 84 Polar Stereographic for the continent of Antarctica.
Image Orientation	Map (North Up)
Distribution	HTTPS Download Only
Delivery Time	Available to dowload within 6 hours

While most Landsat 7 ETM+ scenes are processed to full Terrain Precision Correction ( L1TP), some scenes do not have the ground-control or elevation data necessary to perform these corrections. In these cases, the best level of correction is applied. (See Landsat Processing Details for details on correction levels.)

Specific terrain precision corrected scenes are available for most of the globe under the Global Land Surveys (GLS) collections of 1975, 1990, 2000, 2005, and 2010. These datasets can be found on EarthExplorer.

Landsat 7 ETM+ Collection 2 Level-1 Data

Landsat Tiers are the inventory structure for Landsat Collection 2 Level-1 data and are based on data quality and level of processing. All scenes in the Landsat archive are assigned to a Collection category. The purpose of Collection categories is to support rapid and easy identification of suitable scenes for time-series pixel level analysis. These data have well-characterized radiometric quality and are cross-calibrated among the different Landsat sensors.

Collection Category (Tier)

Tier 1 (T1) - Contains the highest quality Level-1 Terrain Precision (L1TP) data considered suitable for time-series analysis. The georegistration is consistent and within prescribed tolerances [<12m root mean square error (RMSE)]
Tier 2 (T2) – Contains Contains L1TP scenes not meeting Tier 1 criteria and all Systematic Terrain (L1GT) and Geometric Systematic (L1GS) scenes. Users interested in Tier 2 scenes can evaluate the RMSE and other properties to determine suitability for use in their applications and studies
Real-Time (RT) – Contains newly-acquired Landsat 7 scenes, which require a period of evaluation and calibration adjustment after acquisition but are processed immediately based on preliminary calibration coefficients, assigned to the temporary RT Tier, and made available for download. When definitive calibration information becomes available (approximately 26 days), these scenes are reprocessed, assigned to the appropriate Tier 1 or Tier 2 category, and removed from the RT Tier.

The Landsat Collection page contains additional information about changes applied to Landsat Level-1 data for Collection 2.

Coverage Maps

Coverage Maps indicating the availability of Landsat 7 ETM+ Collection 2 Level-1 data are available for download.

Additional Information

Access Data

Landsat 7 Collection 2 Level-1 scenes held in the USGS archive can be searched using EarthExplorer. On EarthExplorer, Landsat 7 scenes can be found under the Landsat menu in the “Landsat Collection 2 Level-1” section, in the “Landsat 7 ETM+ C2 L1” dataset.

Newly acquired Landsat 7 scenes become available for search and download within 6 hours after data acquisition. To view real-time acquisitions of Landsat 7, please visit EarthNow!