LVIS Data Structure (LDS) 2.0.4 Description


Byte Order: Binary files are Big Endian unless otherwise noted.


Reference Frame: WGS-84 Ellipsoid


General Notes:

  • A release is comprised of two or more file types sharing a common origin. All files within the release have equal record numbers, and correspond to one another laser shot for shot. (i.e. record 1000 in the .h5 file will be the same laser shot as record 1000 in the .txt file for a given data set)

Datasets: 2022 (ice surfaces)



Level 1B Geolocated LVIS Waveforms (HDF format)

Item Byte Size Format Units Item Description
LFID 4 unsigned longword integer LVIS file identification
shotnumber 4 unsigned longword integer Laser shot number assigned during collection
azimuth 4 single precision floating point degrees Azimuth angle of laser beam
incidentangle 4 single precision floating point degrees Off-nadir incident angle of laser beam
range 4 single precision floating point meters Distance between the instrument and the ground
time 8 double precision floating point seconds UTC decimal seconds of the day
lon0 8 double precision floating point degrees Longitude of the highest sample of the waveform (Degrees East)
lat0 8 double precision floating point degrees Latitude of the highest sample of the waveform (Degrees North)
z0 4 single precision floating point meters Elevation of the highest sample of the waveform
lon1215 [lon1023] 8 double precision floating point degrees Longitude of the lowest sample of the waveform (Degrees East)
lat1215 [lat1023] 8 double precision floating point degrees Latitude of the lowest sample of the waveform (Degrees North)
z1215 [z1023] 4 single precision floating point meters Elevation of the lowest sample of the waveform
sigmean 4 single precision floating point counts Signal mean noise level, calculated in-flight
txwave counts Transmitted waveform, 128 bins, 12 [10] bits @ 1GHz
rxwave counts Return waveform, 1216 bins, 12 [10] bits @ 1GHz

Variables and bitwidths in [brackets] are for LVIS Classic (LVISC)


Level 2 Geolocated Surface Elevation and Height Product (ASCII Text format)


Item Units Item Description
LFID LVIS File Identification
shotnumber Laser shot number assigned during collection
time seconds UTC decimal seconds of the day
lon_low degrees East Longitude of the lowest detected mode within the waveform (Degrees East)
lat_low degrees North Latitude of the lowest detected mode within the waveform (Degrees North)
z_low meters Mean elevation of the lowest detected mode within the waveform
lon_maxamp degrees East Longitude of the peak mode within the waveform
lat_maxamp degrees North Latitude of the peak mode within the waveform
z_maxamp meters Mean elevation of the peak mode within the waveform
lon_high degrees East Longitude of the highest detected mode within the waveform
lat_high degrees North Latitude of the highest detected mode within the waveform
z_high meters Mean elevation of the highest detected mode within the waveform
lon_low_alternate degrees East Alternate lowest mode location, based on lower signal detection threshold
lat_low_alternate degrees North Alternate lowest mode location, based on lower signal detection threshold
z_low_alternate meters Alternate lowest mode location, based on lower signal detection threshold
azimuth degrees Azimuth angle of the laser beam
incidentangle degrees Off-nadir incident angle of the laser beam
range meters Distance between the instrument and the ground
complexity Complexity metric for the return waveform
sensitivity Sensitivity metric for the return waveform
energy1 counts Signal return energy for channel 1
energy2 counts Signal return energy for channel 2
energy3 counts Signal return energy for channel 3
channel Flag indicating LVIS channel used to extract L2 parameters

Use the following python script to view Level 1B and Level 2 data products in the LDS v2.0 format. You will need to install the h5py and numpy python packages in order for this script to work.

py_waveplot.py