"Proceedings, Federal Interagency Workshop,
"Sediment Technology for the 21'st Century,"
St. Petersburg, FL, February 17-19, 1998"

Video Imaging for Bedload Sensor Calibration

By R.A. Schmidt


This idea uses two video cameras and solid-state light sources, together with an image analysis program, for calibrating bedload monitoring systems. Extremely small, low-power video cameras (e.g., 0.6 x 0.6 x 1.4 inches, 30 ma @ 6-18 V) give resolution of 240 to 410 lines, in minimum light levels down to 0.05 lux for a price of $100-$300 (Fig. 1). Two such cameras might be mounted with semiconductor light sources, as shown in the sketch (Fig. 2), to give images for sediment size and speed analysis, in both laboratory and field situations.

figure 1
Figure 1. Comparison showing the small size of an example microvideo camera.

Industrial inspection software is available for analysis in real-time. If the idea works for pebbles, improvements, such as color and greater image resolution, might detect certain aquatic insects. (It seems likely to me that someone already tried this.)

Technical problems include finding a scratch-resistant window material, and synchronizing recordings if the signals are recorded in the field for later analysis.

figure 2
Figure 2. An idea of how microvideo cameras and light-emitting diodes might be mounted in a chamber set flush with the bed surface, to measure sediment.

One source of cameras:

One Supercircuits Plaza
Leander, Texas 78641
(512) 260-0333

One source of inspection software

Industrial Perception Systems, Inc.
2661 Clearview Road
Allison Park, Pennsylvania 15101
(412) 492-0200

Workshop Contributions

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