Background

The Harmonized Landsat and Sentinel-2 (HLS) dataset is a Satellite Needs Working Group (SNWG)-2016 solution. The synergistic use of Landsat and Sentinel-2 data results in a global dataset of surface reflectance with a temporal resolution of two days while retaining the geometry and 30-m spatial resolution of Landsat data. The high temporal resolution combined with the ability to seamlessly use the HLS in 30-year time series of Landsat data has resulted in widespread usage of HLS data. The latency of the data of three to four days was constrained by Moderate Resolution Imaging Spectroradiometer (MODIS) atmospheric correction data. There is an opportunity to decrease the latency with the migration from MODIS to the Visible Infrared Imaging Radiometer Suite (VIIRS).​

Status

This activity is currently in pre-formulation. The quality of the near-real time MODIS data was deemed insufficient for production of low-latency HLS. The proposed solution will make use of the improved near-real time VIIRS data to produce HLS data with a latency of 6 hours through NASA's Land, Atmosphere Near-real-time Capability for Earth observing system (LANCE).

Solution Characteristics

Societal Impact

The HLS dataset is compatible with the 40-year Landsat record but with a higher temporal resolution of two days. These features have made HLS popular across disciplines and institutions. Considering the widespread usage of HLS among Federal agencies, a low latency version of HLS -- here defined as a 6-hour latency -- will enhance Agencies' ability to respond to wildfires, earthquakes, droughts, oil spills, etc.​