Author
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Booth, D |
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GLENN, D - USDI-BLM |
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KEATING, B - USDI-BLM |
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COX, S - ARS TEMP |
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NANCE, J - CLOUD 9 |
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BARRIERE, J - TRACK'AIR SURVEY SYSTEMS |
Submitted to: American Society for Photogrammetry and Remote Sensing Proceedings
Publication Type: Proceedings Publication Acceptance Date: 1/2/2004 Publication Date: 1/15/2004 Citation: Booth, D.T., Glenn, D., Keating, B., Cox, S.E., Nance, J., Barriere, J.P. 2004. Monitoring rangelands with very-large scale aerial imagery. American Society for Photogrammetry and Remote Sensing, CD Proceedings. Interpretive Summary: Technical Abstract: Rangeland management has depended more on judgement than science for monitoring vast landscapes. The result is a crisis of confidence and recognition that we need objective information based on standardized indicators. We recognize the complex, multivariate nature of rangeland ecosystems; we also recognize that information-collection costs require that we define key indicators -- those that lend themselves to detection of ecological important change with minimal expense. Therefore we are testing bare ground as a potential key indicator and we are investigating very-large scale aerial (VLSA) imagery as a means for inexpensive acquistion of statistically adequate, unbiased, high-resolution (high detail), samples (images) from which to make accurate ground-cover measurements. Our remote-sensing tools include an ultra-light-type, 3-axis airplane capable of straight and level flight at 73 km/hr, 100 m above 1520-m elevational rangelands; a laser altimeter for precise, instantaneous measurements of platform altitude above ground level (AGL); and high-shutter speed film and digital cameras automatically triggered by computer using pre-programmed coordinates with an interfaced geographic positioning system. The system provides the pilot with navagational information including ground speed, a critical parameter in close-to-the-earth photography. Our methods for making bare-ground measurements from the imagery include manual photogrammetry and digital methods (color density slicing image analysis). Ground truth is being collected using both laser-bar point frames and image analysis of 2-m AGL digital photographs from a stationary platform. |