The CALYPSO Professional Data Interface consists of three main components, namely:

• The Data QuickView section;
• The Data Daily Download section; and
• The Data Aggregated Download section.

The Data QuickView section allows the viewing and downloading of data on an hourly basis for the entire domain. The user selects the date of interest, and gets presented with set of images of the currents for the selected date-time. The user is allowed to download the data (as NetCDF or Ascii Columns file) for any specific hour. Apart from all this, the user may also view an animation of the currents for the selected day.

The Data Daily Download section presents the data for download for any month selected by the user. The data is aggregated on a daily basis. Hourly NetCDF files are concatenated together to create the daily files, whilst the Ascii files are aggregated as daily RAR archives. After the user selects the month of interest, the system shows the list of days for which there is data available. The data for each day may be downloaded in any format – i.e. NetCDF, Ascii Columns and Ascii Matrix Files.

The Data Aggregated Download section allows the aggregation and download of data over a range of days. The user selects the start date and the end date of the period of interest, and the desired data form (NetCDF, Ascii Columns and Ascii Matrix Files). The system performs the aggregation of data files between the start date and the end date provided that this period does not exceed 100 days. Once the aggregation is completed, the system outputs a link to the resulting aggregated file, and also informs the user of the days for which data is included in the aggregated file.

Data Formats

The Calypso HF-Radar Professional Data Interface disseminates real time currents data in three different formats:

• NetCDF Files: these are binary files that contain all the currents data collected by the Calypso HF-Radar Network. This includes: Time, Longitude, Latitude, Eastward Water Velocity (U), Northward Water Velocity (V), Standard Deviation of the Eastward Water Velocity (U), Standard Deviation of the Northward Water Velocity (V), and the Covariance. NetCDF files may be read by various readers (such as ncdump and Panoply). More information about the NetCDF format may be found on: http://www.unidata.ucar.edu/software/netcdf/ .
• ​ ASCII Column Files: – these are ASCII text files that contain 4 columns, namely: Longitude (in degrees East), Latitude (in degrees North), Current Magnitude (in m/s), and Current Direction (in degrees from North). Data points for which there is no data are omitted from these files. These files may be read in any text editor, or standard spreadsheet software (such as MS Excel and/or OpenOffice Calc).
• ASCII Matrix Files: these are tab-separated ASCII files, where the Eastward Current Velocities (U) and the Northward Current Velocities (V) are stored as matrices in separate files. A single row in each of these matrix files corresponds to a single row of grid cells (i.e. cells with the same latitude), and the top row represent the grid row with the lowest latitude whilst the bottom row represents the grid row with the highest latitude. These files can be opened with any text editor. However, they are targeted to be processed in a way similar to CSV files using spread-sheet software (such as MS Excel and/or OpenOffice Calc) and/or other data processing software such as R and Matlab.

​ The temporal resolution of the Calypso HF-Radar data is hourly. However, the system aggregates the data files into daily files, or into larger files according to the user requests. In case of the NetCDF files, the aggregation is performed by joining the hourly NetCDF files together along the time dimension. In the case of the ASCII files, the aggregation is performed by creating RAR archives containing the necessary ASCII hourly files.