Data File Description
Solar data elements measured and reported by the CONFRRM sites include global horizontal irradiance (GHI), direct normal irradiance (DNI), diffuse horizontal irradiance (DHI), and global horizontal irradiance measured with a LI-COR pyranometer. Meteorological data include air temperature, relative humidity, pressure, wind speed, wind direction and peak wind speed. Data logger temperature and battery voltage may also be reported. Some sites measure only two of the three broadband solar components (global horizontal, direct normal and diffuse horizontal irradiance), while others include several meteorological measurements as well as the solar measurments.. Table 1 lists all fields which may be found in a CONFRRM data file, and indicates the format for each field. Sites which include this field in their data files are also indicated in the table. For a list of measurements made at each site, and their order in the data record, please see Table 2.
The format of the data files is comma delimited ASCII, each file containing one calendar month of quality assessed data. Data quality assessment is performed on the broadband solar radiometric data using SERI_QC, which assigns data quality flags to every solar radiation component at every point in the data file. Flags assigned to other data indicate that the measurement passed or failed minimum/maximum tests; or, in the case of a blank flag field, that no data quality tests were performed.
Data File Format
Data File FormatThe CONFFRM solar radiation data files are comma delimited ASCII text files. Table 1 lists the fields possible in a CONFRRM solar data file, indicating which sites measure each parameter. For a list of the parameters measured at each site and their order within a data record see Table 2.
The following is an example of a CONFRRM solar radiation data file, this one from Elizabeth City State University (EC):
1997,8,1,12,0,781.21,14,821.77,15,53.02,15,27.50,01,38.88,01,30.38,01 1997,8,1,12,5,779.49,14,818.92,15,52.46,15,27.41,01,39.68,01,30.50,01 1997,8,1,12,10,779.38,14,816.37,15,52.51,15,27.24,01,41.16,01,30.48,01 1997,8,1,12,15,778.82,14,816.09,15,52.65,15,27.25,01,42.16,01,30.55,01 1997,8,1,12,20,778.53,10,814.33,11,52.61,11,26.98,01,43.12,01,30.45,01 1997,8,1,12,25,778.87,10,814.85,11,52.43,11,26.88,01,42.90,01,30.46,01 1997,8,1,12,30,778.60,14,816.57,15,53.50,15,27.00,01,42.98,01,30.36,01 1997,8,1,12,35,776.30,10,814.61,11,53.45,11,27.13,01,42.82,01,30.31,01Each line, or record, represents five minutes, the data within each record being 5-minute averages. According to Table 2, the first field is the four-digit year, 1997. The next field represents the month, in this case August. Next comes the day of the month, then the hour of the day, 0-23; then the minute, 0-59.
Following these first five fields are the actual measured data. From Table 2, we see that in the first line the global horizontal irradiance was 781.21 W/m2, and was given a flag 14 by SERI_QC.
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