FAQs on ICESat-2 quick looks

Read this help article to learn about what ICESat-2 quick look data products are and how to find them.

What are ICESat-2 quick looks?

The Advanced Topographic Altimeter System (ATLAS) on board the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) collects elevation data over all surfaces spanning the world’s frozen regions, forests, lakes, urban areas, and more. ICESat-2 data has a standard latency of 30-45 days, meaning it is made available to users 30-45 days after satellite observation.

The ICESat-2 mission, at the recommendation of the Satellite Needs Working Group, provides a subset of ATLAS/ICESat-2 data sets such as sea ice height, land and vegetation height, atmospheric layer characteristics, sea ice freeboard, and inland water surface heights available at an expedited latency. These ICESat-2 “quick look” data sets will be provided to users within 3 days of satellite observation. 

How long are ICESat-2 quick look data available?

ICESat-2 quick look data files will be removed when the corresponding final standard data file is published, which typically occurs 30-45 days after satellite observation. 

If a final standard file is not created (due to the overall quality), the quick look file will be removed 3 months after it was published.

What can ICESat-2 quick look data be used for?

These ATLAS/ICESat-2 quick look data sets with expedited latency have a wide range of potential applications including sea ice forecasting and supporting decision-makers looking at vegetation height, surface water and flooding, and land surface deformation from landslides and volcanoes.

Are there data quality differences between ICESat-2 standard and quick look data sets?

The primary differences between ICESat-2 expedited latency quick look data and the standard data are the geolocation uncertainty and the uncertainty in the reported heights. The final data products are based on the best possible solutions for the position of the satellite in space through time. The quick look data are based on less precise solutions for the position of the satellite in space through time. 

Quality differences between quick look and standard data will vary from data set to data set.  For more details on the exact limitations, examine section 2.4.1 of the user guide attached to each quick look data set. On the quick look data set landing page, click the “User Guide” tab at the top, then scroll down to section 2.4.1, “Quick Look Data Quality.” 

If latency is not a primary concern, users are encouraged to use the standard science data sets, which are created using the best available information.

How can I find and download ICESat-2 quick look data?

There are five quick look data sets currently available for ICESat-2, listed below. In order to download these data sets, you will need to register for an Earthdata Login.

1. L3A Sea Ice Height Quick Look (ATL07QL) 
2. L3A Land and Vegetation Height Quick Look (ATL08QL)
3. L3A Calibrated Backscatter Profiles and Atmospheric Layer Characteristics Quick Look (ATL09QL)
4. L3A Sea Ice Freeboard Quick Look (ATL10QL)
5. L3A Along Track Inland Surface Water Data Quick Look (ATL13QL)

ICESat-2 quick look data sets are also visible on NSIDC’s ICESat-2 data list and on the Earthdata LANCE ICESat-2 landing page. You may notice that all quick look data sets for ICESat-2 have QL as the last two letters of the data set ID (ex. ATL07QL), and its status as a quick look data set is described in both the title and overview on the data set landing page. You can also locate all ICESat-2 quick look data sets in NSIDC Scientific Data Search by typing “ICESat-2 quick looks” in the search field at the top, or by clicking this link.

Additional expedited latency/quick look versions of other ICESat-2 data sets may be published based on user community needs and other priorities. 

To be notified of issues, outages, and updates concerning a quick look data set, click the “Mailing List” icon in the top right of the landing page.