Linear unmixing of spectra from daytime Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images can be used to improve the spatial resolution of temperatures calculated for streams that are not fully resolved in the 90-m thermal infrared (TIR) data. We first examine ASTER 15-m Visible-Near Infrared (VNIR) data to select three endmembers using a simple automated technique. These endmembers correspond to vegetation, shade/water, and other scene components (e.g. urban/soil/non-photosynthetic vegetation). Then the 15-m VNIR data are unmixed into the three corresponding fraction images. Threshold and adjacency tests are used to separate the shade and water fractions creating a total of four fraction images that together are used to specify the amount of the scene components in each 90-m TIR pixel. The emitted thermal radiance (ETR) from each of the scene components can be estimated if we assume that it is the same as for a
A stereoscopic system was developed that integrates hardware and software components for image acquisition, digitization, processing, display, and measurements. The model-induced trajectories of nearly neutrally buoyant fluorescent particles, illuminated with a 15-W pulsed copper vapor laser, are tracked in a towing tank by stereoscopic time-lapse photography using two 35-mm cameras positioned at a 90-degree angle from the top and the side. A C program, HI, drives two data I/O boards hosted in a PC to set up the run parameters, control the operations of the laser and camera shutters, and acquire the stereo images. The photographic records are digitized and processed to derive the centroids of reference marks and particle images. The centroids are then fed into a Windows-based program, Track/3D, to perform image correlation, correction for image distortion, stereo conversion, stereoscopic display, and measurements. The display module incorporates a graphics library that drives a stereoscopic display adapter attached to a monitor; the stereogram must be viewed with polarizing glasses. Functions are available for image translation, rotation, zooming, and on- screen measurements. The velocity and acceleration components of the 3-D flow field induced by the model are derived from the trajectories, serving as a basis for whole-field stereoscopic quantitative flow visualization.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.