Stations/Data ReadMe File

Selecting a Location:

You can now select a site location by clicking on the Climatological/Research Site Locations Map. Doing so will take you to a page with a photograph of the site and the information described under Site Information below.

From within the sections described under Data Sections, below, site locations are selected by State,Town & Location Type from pull down menus containing all three of our location types, identified by both color and letter designation.

Climate(C)(yellow) - Standard Climatological Site.

Most of these sites are equipped with our full set of standard instrumentation and have up-to-date UV-MFRSR calibrations.

Research(R)(blue) - Research Site.

These sites usually have an incomplete set of instruments, but have up-to-date UV-MFRSR calibrations.

Short Term(S)(green) - Short Term Site.

These are unique sites that operate(d) for a short period of time. Our intercomparison sites fall into this category.

If more than one Short Term or Reseach site has operated at a given location, they are listed as S, S1, S2 or R, R1, R2 in the pull down menus.

To determine if data for a particular time period might be available from a number of locations in which you are interested, first review the opening dates of the sites. They are given in the Listing of Sites under the Climatological/Research Site Locations Map. Next, you may wish to find the locations on the map to see if one or more have closed. (Closed sites are indicated by green dots.)

For more detailed information regarding a specific location, including the types of instruments that are/were in use and closing date (if applicable), use the Site Information section. To determine whether the particular kinds of data you need are available, use the History buttons on the location's Site Information page to view the operational histories of specific instruments at that location. See the description of Site Information below for more details.

• In the Site Information section dates are given as:  yyyy/mm/dd.
• Dates on plots are typically shown in the format mm/dd/yyyy in plot titles, and as mm/dd on axis labels.
• In data files that can be downloaded, the standard timestamp format is:  yyyy,mm,dd,hh24,mi,ss.

After careful consideration and consultation with several data users, we have determined that changes in our file formats and data delivery are in order. Although format changes initially result in extra work for you, we hope you will find them helpful in the long-run. The format changes are listed below:

• All data fields will now be of fixed length. Some values will be given in exponential format; floating point values will be consistently rounded as appropriate for each item.
• We have added a multi-line header to each file. The first line gives the total number of header lines in the file.
• Additional header lines briefly describe each data column, or group of similar columns in some cases. These lines specify the contents of the column(s), abbreviated field name(s), and units.
• The last header line consists of all abbreviated field names, centered over the data columns for easier viewing.
• An end of data marker #EOD is added following the last line of data.
• The naming convention for data files will be SITEYYYYmmdd.TYP.dat
  1. where SITE = Site ID code
  2. YYYYMMDD = Starting Date
  3. TYP = cal for calibrated irradiance data, aux for auxiliary data
• QC code fields will never be completely missing, blank, or filled with "null." If there are no known qc problems with a data record, the qc code field will have a zero at the end of the field.

• Site Information:

  This will give you all the available information about a location, including the last calibration date for all instruments at that location and our internal site identification code, which appears in data files. We also allow you to get the history of the site by clicking on the History button. Simply click on Site Information, select the location and press Get. The information will appear. Alternatively, you can make your location selection by clicking on it from the Climatological/Research Site Locations Map.

• Data Plots:

  This section gives you data plots/data files for all our instruments.

  The first four options give access to data from one site for a day, week or month. You can select from Lamp-Calibrated Channel data, Langley-Calibrated Channel data, Angular (Cosine) Corrected Voltages, or Auxiliary Data (air temperature, humidity etc.)

  To access data from these four options, select the site and make the other menu selections, then decide whether you want to view plots or only a data file. If you select Data File you will then be allowed to view and download the ascii data. If you select Data Plot, the plots will appear as icons. Just click on one of the plots to display a larger version. If you would like to compare specific plots select Compare Plots. If you would like to download the data used in the plot as an ascii file, select Download Data.

  If you used a previous version of our website, the old Channel Data option was analagous to the new Lamp-Calibrated Channel data option. Calibration factors for the new lamp-calibrated data are determined by linearly interpolating the starting and closing gains. Previously, only the starting gains were used.

  For most time periods, data calibrated by the Langley method are now available. Whereas lamp-calibrated data typically become available the next day after collection, you can expect a 1 to 5 week delay for Langley-calibrated data. Langley calibrations are updated monthly, usually after the first week of each month. See Data Processing Procedures for information about the Langley method of calibration.

  The last three options allow you to retrieve the latest plots from the UVB-1 Broadband, UVA Broadband, or PAR Sensor for all sites for one date. These selections give one plot per site. The plots will appear as icons. Just click on one of the plots to display a larger version. If you would like to download the plot as an ascii file, select Download Data.

• Instrument Characteristics:

  This section allows you to plot and download data that characterize our multi-filter shadow-band radiometers. The Angular(Cosine) Plots display laboratory-measured angular responses of the detectors; the Filter Function Plots show the bandwidths and centers of wavelength. Choose V₀ Time Series plots to view the Langley voltage intercepts that are used in assessment instrument stability, in generating the Data Products mentioned in the next section, and for Langley calibration. After you select a site, a date, and the instrument type and press Plot, one or more plots per channel will appear. Click on a plot to see it enlarged. To download the data, press the Download Data button.

• Data Products:

  Optical Depths and Column Ozone data can be plotted and downloaded from this section. In all cases you will be asked to select a site, a starting date and a period length of one day to a month or year. For optical depths you will have additional selections to make. One day of data is shown in a table; longer periods are plotted. Click on a plot to enlarge it. Press Download Data to download an ascii file of the data.

  The new Langley Plots option allows you to run the Langley Analyzer program on individual, relatively clear morning and afternoon periods and view plots summarizing the results. Here you will make your selections from two menu screens. From the first screen, select a location, instrument type and month, and decide if you would like to use our default parameter settings or customize them. Press continue after you have made your choices. On the second menu screen you will find a drop-down list of the days on which we have obtained Langley results for morning and/or afternoon periods. Select a date and time period from the list. If you chose to customize the program paramters, the setting options will be available from this second screen. After you press Execute, the plots will appear. Click on a plot to see a larger version; click your browser's Back button to go back to the page of small plots. A Download Data function for this new data product is planned for the future.

  Data products are updated at monthly intervals, typically during the first week of the month. For example, column ozone data for January could become available as early as February 7.