Developed and tested by Dr. Ed Root, the IEDRO Strip Chart Digitizer program retrieves data from scanned strip chart images and converts them into an accurate computer-readable format.
IEDRO’s Strip Chart Digitizer Program
Developed and tested by Dr. Ed Root, the IEDRO Strip Chart Digitizer program retrieves data from scanned strip chart images and converts them into an accurate computer-readable format. The program is five to ten times faster than a trained person performing hand tracing.
Hydrometeorological “strip charts” record the changes in parameter values over time. Observational data such as temperature, atmospheric pressure, relative humidity, precipitation, stream flow, wind direction and speed, etc., are recorded as a pen trace on a grid. These charts are mounted on cylinders which rotate at a constant speed, and a pen, attached to a mechanical device, records the changes in parameter values over time. Depending on the speed at which the cylinder turns, the charts may represent parameter changes over a 24-hour period or a 7-day week.
Prior to the construction of the IEDRO Strip Chart Digitization Program, the process of extracting information from these charts and digitizing the values over specific periods of time involved manually running a digitizing pen over the trace on the chart (which was mounted on a light table), and then entering the data on a form. This manual process usually took 15 to 20 minutes of effort.
Dr. Ed Root, one of IEDRO’s talented volunteers, spent nearly 3 years developing a computer program that will take a scanned or digitally photographed image of one of these charts and digitize the entire chart at any time interval requested. The digitized data can be provided in a comma delimited file or transcribed in a table. The time required for the program to digitize a chart? Less than 5 seconds!
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