Title

Time-lapse Camera System for Monitoring Short- and Long-term Sedimentary Processes

Document Type

Article

Publication Date

2011

Abstract

Time-lapse photography has seen limited use as a method for observing sedimentary processes. A problem with past techniques is the use of expensive components, limiting availability for most applications. The purpose of this project is to develop a low-cost, modular time-lapse system for both short- and long-term deployment in the field to photographically monitor various sedimentary processes, such as erosion and deposition of shoreline sediments during a single storm event or seasonal sand dune migration. Images that are taken at regular intervals can be compiled into a video to display the effects of the processes under observation. Other considerations for the camera units besides cost are that the cameras must be as inconspicuous as possible and able to run reliably for long periods of time without power supply or storage space issues. We use inexpensive 10 megapixel point and shoot cameras with a 16 GB memory card and the open source Canon Hack Development Kit (CHDK) installed. CHDK allows customized user control of various features and capabilities within the camera, including the ability to run scripts written in uBASIC or Lua. We use an intervalometer script in place of a physical intervalometer unit, further reducing hardware costs. The unit’s power source is a 12V battery, either a compact sealed lead acid battery for short-term deployments, such as to monitor a storm event, or a deep cycle battery for long-term deployments. A solar panel can optionally be used to recharge the batteries and prolong the deployment. The cameras are enclosed in a waterproof, dustproof container to protect them from adverse conditions and theft. The advantage of this system over trail cameras is the level of control and higher resolution for comparable cost. Various open source or commercial software packages can compile images into a video. The original image can be reduced in size to an appropriate video resolution, or a section of the images can be cropped to produce a more detailed video of a smaller area. The system we have developed costs less than $300. It allows capture of up to 5,400 images at intervals as frequent as one image per minute without changing memory cards, and even without a solar panel allows deployments of up to one month between site visits to change batteries.