Assessing the Ability of Laser Altimeter Return Waveforms To Detect Surface Topographic Change
Abstract
The capability of medium/large footprint (10 m or greater) full-waveform laser altimeters to penetrate beneath dense vegetation to directly measure sub-canopy topography provides a unique capability for sensing topographic change in the presence of vegetation. In this study, we assess the ability of geolocated laser altimeter return waveforms instead of individual elevation measurements to measure vertical elevation change. The method we use (dubbed the return pulse correlation method) maximizes the shape similarity of near-coincident, vertically-geolocated laser return waveforms from two observation epochs as they are vertically-shifted relative to each other. Using waveform data collected by NASA's Laser Vegetation Imaging Sensor (LVIS) we assess the inherent precision of elevation change measurements derived using the return pulse correlation method. Data collected in 1999, 2003 and 2004 are compared using the pulse correlation method and by simple differencing of coincident elevation measurements. Data collected under "bare earth" conditions as well as in the presence of dense, growing vegetation are utilized, demonstrating the usefulness of this technique for complementing and extending earth surface dynamics measurements made using other remote sensing techniques.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AGUFM.G13B0809H
- Keywords:
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- 5464 Remote sensing;
- 1206 Crustal movements: interplate (8155);
- 1294 Instruments and techniques;
- 1640 Remote sensing