The best way to find and use ATM data is through the NSIDC IceBridge portal.
Below are direct links to data housed at NSIDC
Altimetry Products |
QFIT (narrow & wide) |
ICESSN |
dh/dt |
Waveforms |
Ancillary Data Products | |
KT-19 Pyrometer | Thermal Imaging (FLIR) |
Camera/Optical | Spectrometer |
GPS trajectories |
The primary data product from the ATM laser altimeter is “QFIT”. A QFIT file is a collection of geolocated laser shots tagged with time and elevation. ICESSN is a sub-sampled version of QFIT which separates the data in platelets making it smaller and easier to analyze. An example of QFIT vs ICESSN is in the image below
More recently, the ATM group has begun releasing waveform data to complement the standard altimetry products. These waveform data are of particular use when the surface within a single laser footprint is not uniform. Conditions such as pressure ridging on sea ice, or melt ponds that produce surface and bottom returns are examples where a single elevation measurement is inadequate and the waveform data is necessary to accurate interpret the return signal.

Example of surface conditions that would cause multiple waveform peaks to be observed.

Example of complex return waveforms (blue) over a sea-ice pressure ridge. The transmit waveform is shown in dashed gray and scaled to the maximum amplitude of the return pulse to show the deviation of the return pulse. The vertical dashed line in both panels marks the location of the centroid. Multiple separate return pulses can be identified in (a), but the overlapping pulses in (b) result in the centroid estimate being shifted, indicating that the centroid estimates from complex return pulses need to be interpreted properly.