Landsat 8-9 L1

About Landsat 8-9 OLI-TIRS Collection 2 Level 1 Data

Mission Information

Landsat 8-9 Level 2 collection includes both Landsat 8 and the most recently launched Landsat 9 satellites (provided by NASA/USGS), both carrying the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS) instruments, with 9 optical and 2 thermal bands. These two sensors provide seasonal coverage of the global landmass. Learn more about the collection here.

Basic Facts

Accessing Data

To access data you need to send a POST request to our process API. The requested data will be returned as the response to your request. Each POST request can be tailored to get you exactly the data you require. To do this requires setting various parameters which depend on the collection you are querying. This chapter will help you understand the parameters for Landsat 8-9 Level 1 data. For an overview of all API parameters see the API Reference.

Endpoint Locations

Data type identifier: landsat-ot-l1

Use landsat-ot-l1[1] (previously LOTL1) as the value of the input.data.type parameter in your API requests. This is mandatory and will ensure you get Landsat 8-9 Level 1 data.

The collection is currently in the preview stage and might thus change.

[1]:landsat-ot-l1 stands for Landsat OLI-TIRS Level 1.

Filtering Options

This chapter will explain the input.data.dataFilter object of the process API.

mosaickingOrder

Sets the order of overlapping tiles from which the output result is mosaicked. Note that tiles will in most cases come from the same orbit/acquisition. The tiling is done by USGS for easier distribution.

maxCloudCoverage

Sets the upper limit for cloud coverage in percent based on the precomputed cloud coverage estimate for each tile as present in the tile metadata. Satellite data will therefore not be retrieved for tiles with a higher cloud coverage estimate. For example, by setting the value to 20, only tiles with at most 20% cloud coverage will be used. Note that this parameter is set per tile and might not be directly applicable to the chosen area of interest.

tiers

Selects product tiers.

Processing Options

This chapter will explain the input.data.processing object of the process API.

Available Bands and Data

Information in this chapter is useful when defining input object in evalscript. Any string listed in the column Name can be an element of the input.bands array in your evalscript.

[1]: TIRS bands are acquired at 100 meter resolution, but are resampled to 30 meter in delivered data product (source).
[2]: dataMask has no source resolution as it is calculated for each output pixel.

Units

The data values for each band in your custom script are presented in the units as specified here. In case more than one unit is available for a given band, you may optionally set the value of input.units in your evalscript setup function to one of the values in the Sentinel Hub Units column. Doing so will present data in that unit. The Sentinel Hub units parameter combines the physical quantity and corresponding units of measurement values. As such, some names more closely resemble physical quantities, others resemble units of measurement.

The Source Format specifies how and with what precision the digital numbers (DN) from which the unit is derived are encoded. Bands requested in DN units contain exactly the pixel values of the source data. Note that resampling may produce interpolated values. DN is also used whenever a band is derived computationally (like dataMask); such bands can be identified by having DN units and N/A source format. DN values are typically not offered if they do not simply represent any physical quantity, in particular, when DN values require source-specific (i.e. non-global) conversion to physical quantities.

Values in non-DN units are computed from the source (DN) values with at least float32 precision. Note that the conversion might be nonlinear, therefore the full value range and quantization step size of such a band can be hard to predict. Band values in evalscripts always behave as floating point numbers, regardless of the actual precision.

The Typical Range indicates what values are common for a given band and unit, however outliers can be expected.

[1]: Top of the Atmosphere Reflectance, which is obtained using the scene center sun angle.
[2]: Top of the Atmosphere Brightness Temperature.

Scenes Object

scenes object stores metadata. An example of metadata available in scenes object for Landsat 8-9 L1 when mosaicking is ORBIT:

Properties of a scenes object can differ depending on the selected mosaicking and in which evalscript function the object is accessed. Working with metadata in evalscript user guide explains all details and provide examples.

Catalog API Capabilities

To access Landsat 8-9 product metadata you need to send search request to our Catalog API. The requested metadata will be returned as JSON formatted response to your request.

Endpoint Locations

Collection identifier: landsat-ot-l1

Filter extension

• eo:cloud_cover cloud cover percentage
• landsat:scene_id scene identifier
• landsat:collection_category collection tier. T1 for tier 1 (scenes with the highest radiometric and positional quality) and T2 for tier 2 (scenes not meeting tier 1 criteria)

Distinct extension

• date