Knowledge Base

ICESat
ICESat - FAQ
Why are laser footprint shape parameters not available for low energy campaigns?

Several parameters help quantify the shape of the GLAS laser footprint ... Read more

What is the basic difference between a standard and alternate waveform fit and when would you normally choose one over the other?

The standard waveform fit is optimized for "ice sheet-like" returns. ... Read more

What data subsetting and reformatting services are available for ICESat/GLAS data?

The following table describes the data subsetting and reformatting ... Read more

What is meant by the first and last shot in the record?

There are 40 laser shots in one second which are associated with the ... Read more

In the GLAS altimetry products, is there an indicator to the presence of clouds?

Yes, it is an element of GLAH06, GLAH12, GLAH13, GLAH14, and GLAH15. ... Read more

How is the surface elevation at each laser footprint determined?

In short, the elevation of the surface at each laser footprint is the ... Read more

What is the accuracy of GLAS elevation measurements?

Surface roughness greatly affects the elevation measurement accuracy. ... Read more

Are the altimetry data adjusted to the Geoid, or only to the Ellipsoid?

The elevation data are relative to the ellipsoid. The data also have a ... Read more

How often were data collected for a given geographic area?

The first several months of ICESat operations were in an orbit that ... Read more

How does GLAS geolocate data and provide off-nadir pointing?

Analysis of altimetric data acquired by the GLAS instrument requires ... Read more

What data subsetting and reformatting services are available for ICESat/GLAS data?

The following table describes the data subsetting and reformatting ... Read more

ICESat - How To
Stepping through the HDFView User Guide with GLAS HDF5 Data

HDFView

https://support.hdfgroup.org/products/java/hdfview ... Read more

How do I import GLAS/ICESat 500 m Laser Altimetry Digital Elevation Model of Antarctica into ArcMap?

The following steps outline the process for visualizing the GLAS/ICESat ... Read more

How do you compute sea ice freeboard using GLAH13 data?

"Freeboard" is a measure of the height of sea ice above the ocean ... Read more

How do I order subsetted ICESat/GLAS HDF5 data in Earthdata Search?Last updated: 5 July 2017

NASA Earthdata Search is a map-based search ... Read more

How to read GLAS HDF5 data into MATLAB, IDL, Python, or NCL

The HDF Group has example code for access and visualization of GLAS ... Read more