ICESat-2 Data Products

ASAS product chart

Product

Name

Description

ATL00

Telemetry Data

Raw ATLAS telemetry in packet format

ATL01

Reformatted Telemetry

Parsed, partially reformatted into HDF5, generated daily, segmented into several minute granules

ATL02

Converted Telemetry Data

Science-unit-converted time-ordered telemetry data, calibrated for instrument effects.

ATL03

Global Geolocated Photon Data

Precise latitude, longitude, elevation and time for every received photon.

ATL04

Normalized Relative Backscatter Profiles

Along-track atmospheric backscatter data. Includes calibration coefficients for polar regions.

ATL06

Land Ice Height

Along-track surface height and slope for glaciers and ice sheets.

ATL07

Sea Ice Height

Height of sea ice and open water leads

ATL08

Land and Vegetation Height

Along-track height of ground and canopy surfaces.

ATL09

Calibrated Backscatter and Atmospheric Layer Characteristics

Along-track cloud and other significant atmosphere layer heights, blowing snow, integrated backscatter, and optical depth.

ATL10

Sea Ice Freeboard

Along-track estimates of sea ice freeboard

ATL11

Slope-Corrected Land Ice Height Time Series

Time series of height at points on the ice sheet, calculated based on repeat tracks and/or cross-overs.

ATL12

Ocean Surface Height

Global open ocean sea surface height

ATL13

Inland Surface Water Data

Along-track inland and near shore water surface height distribution

ATL14

Gridded Antarctic and Arctic Land Ice Height

High-resolution glacier and ice sheet digital elevation model (DEM)

ATL15

Gridded Antarctic and Arctic Land Ice Height Change

Quarterly, annual and multi-annual height change maps for glaciers and ice sheets

ATL16

Weekly Gridded Atmosphere

Polar cloud fraction, blowing snow frequency, ground detection frequency.

ATL17

Monthly Gridded Atmosphere

Polar cloud fraction, blowing snow frequency, ground detection frequency.

ATL18

Land/Canopy Gridded

Gridded ground surface height, canopy height, and canopy cover estimates.

ATL19

Gridded Dynamic Ocean Topography

Gridded ocean height product.

ATL20

Gridded Sea Ice Freeboard

Daily and monthly gridded estimates of sea ice freeboard.

ATL21

Gridded Polar Sea Surface Height

Daily and monthly gridded sea surface height inside regions of sea ice cover.

ATL22

Mean Inland Surface Water Height

Mean height for inland water bodies

ICESat-2 Granules

Each orbit of ICESat-2 data is broken up into 14 granule regions. The granule boundaries limit the size of each ATL03 file and simplify the formation of higher level data products.

ICESat-2 global granules ICESat-2 polar granules

ATLAS Beam Strength

The Advanced Topographic Laser Altimeter System (ATLAS) is a photon-counting laser altimeter and the primary instrumentation onboard the ICESat-2 observatory. ATLAS sends and receives data for 6 individual beams that are separated into three beam pairs. The three beam pairs are separated by 3 kilometers, and the two paired beams are separated on the ground by 90 meters. Each beam pair consists of a weak beam and a strong beam, with the strong beam approximately four times brighter than weak. The spots illuminated on the ground from the ATLAS strong beams are numbered 1, 3, and 5, and the spots illuminated on the ground from the ATLAS weak beams are numbered 2, 4, and 6.

The ICESat-2 observatory can be oriented in one of two positions with respect to the direction of travel. In the forward orientation, the weak beams lead the strong beams and a weak beam is on the left edge of the beam pattern (gt1l). This is reversed in the backward orientation, and the strong beams lead the weak beams with a strong beam on the left edge of the beam pattern (Table 1). The beam strength, spot number, atmospheric profile and spacecraft orientation can all be found as HDF5 attributes of each beam group.

Table 1 ATLAS beam mapping when in the forward and backward orientations
Ground Track
Designation
Forward Orientation
Beam Strength
Backward Orientation
Beam Strength

gt1l

Weak

Strong

gt1r

Strong

Weak

gt2l

Weak

Strong

gt2r

Strong

Weak

gt3l

Weak

Strong

gt3r

Strong

Weak