The track file is a file that will show a series of data points along a line (which does not have to follow any pattern or linearity). Each point can have a data value associated with it and the line will be colored by the IDV based on these values. It must be noted that the IDV requires a specific naming convention to recognize that the file is a track file (otherwise the file will not be parsed correctly). An appropriate name might be “WMI_Lear” followed by any desired name, “WMI_Lear-TrackFile.nc” for example.
The file type should be in the same form as the Column file, rows of data. The data doesn’t have to have any specific order to it (increasing longitude or latitude), but the line will be drawn sequentially from point to point.
Below is a picture of the panel for entering the required metadata on a track file:
The first two requirements are common to all file types, a file to be converted and a file to be created. Use the browse button next to these fields to select the desired files.
The next following fields are identical to the Column fields. The track file is set-up with exactly the same structure of the column file, each data point is represented by one line in the file which will have all the necessary information (latitude, longitude, depth, time and the data value itself). If the user has no depth or time values that is acceptable, but it should be noted that a track file must contain time, and thus the program will automatically insert a time value that will start at 1970 and increment by one second for each data point.
These data fields should be completed in the same manner that would be done if this where a column file. Either enter zero if the data is not part of the file, or enter in the appropriate column (starting the numbering from zero) where the data lays. Extraneous columns do not hamper the program from converting your data, but any extraneous lines within the data will not be dealt with properly and either a faulty file will be create or the program will report an error.
The final fields are common to all file types. The “Is positive depth above or below ground” question (with answer choices above and below) simply means that if the file starts 460km below the surface of the Earth, and you entered in “460” as you’re starting point, then positive would be below the surface. This option can also be changed (with extra work) through the attributes panel, but it is common enough to be a general option on the main panel. The attributes panel is explained fully in the user’s guide.