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Text (ASCII) Point Data Format
If your point (in situ) data is not available in one of the file formats that McIDAS-V can handle, but it can output into a column-oriented ASCII text file, it may still be able to read into McIDAS-V. McIDAS-V supports reading in point observation data in a text comma separated value (CSV) file format.

The metadata of this point data must be specified. This can be done in two ways. First, the file can have two extra header lines that defines for McIDAS-V the fields that are within the file and the types of the fields. The only other requirement is that there must be a latitude, longitude and time field in the data. See below.

Secondly, if there are no metadata header lines defined, the Text Point Data Source will show the Metadata GUI described below.

More information about the format of Time and Lat/Lon symbols can be found in the User Preferences' Formats and Data Preferences page.


Comma separated numeric values

In the simplest form, each line line is an observation at one time and one location:
(index) -> (Time,Latitude,Longitude,Altitude,PSL,GUS,SPD,DIR,TD,T)
Time[fmt="yyyy-MM-dd HH:mm:ss"],Latitude[unit="deg"],Longitude[unit="degrees west"],Altitude[unit="m"],PSL[unit="hPa"],GUS[unit="m.s-1"],SPD[unit="m/s"],DIR[unit="deg"],
2007-01-07 16:00:00Z,32.9,117.1,145.0,1026.1,NaN,0.0,0.0,-2.8,12.8
2007-01-07 16:00:00Z,48.3,92.5,341.0,1003.7,NaN,1.5,170.0,-2.0,-0.99
2007-01-07 16:00:00Z,36.8,98.7,449.0,1024.0,12.4,9.8,330.0,-3.0,3.0
2007-01-07 16:00:00Z,44.3,121.2,938.0,1030.1,NaN,2.1,110.0,-3.3,-1.7

Note also that the first line's structure is quite rigid -- there must be a variable (e.g., index, recNum) that is the domain parameter; this should map to the range values. The second line defines the formatting and units of the parameters. Unit names should be standard international unit specifications (udunits compatible). A list of valid names can be found here. (A complete description of this format is contained in the VisAD README.text file.)

Also note that "Time", as well as the locations as "Latitude", "Longitude" and "Altitude" must be specified (if needed).

Text fields

If there are text fields (i.e., non-numeric data) in the observation, just do this:
(index) -> (Time,Latitude,Longitude,Altitude,ST(Text),T)
Time[fmt="yyyy-MM-dd HH:mm:ss z"],Latitude[unit="deg"],Longitude[unit="degrees west"],Altitude[unit="m"],ST(Text),T[unit="celsius"]
2007-02-16 11:00:00 MST,32.9,117.1,145.0,CA  ,20.6
Here we have a ST field (State from metars). Its field name is defined as "ST(Text)" and its entry in the second line is the same.

Time in multiple columns

If there are time fields that span multiple columns, the colspan keyword should be used:
(index) -> (IDN, Latitude, Longitude, Time, WDIR, WSPD, GST)
IDN, Latitude[unit="deg"], Longitude[unit="deg"], Time[fmt="yyyy MM dd HH mm" colspan="5"], WDIR[unit="deg" miss="MM"], WSPD[unit="m/s" miss="MM"], GST[unit="m/s" miss="MM"]
41001 34.68 -72.66 2007 07 17 20 50 210 4.0 6.0
41004 32.5 -79.09 2007 07 17 20 50 210 6.0 MM
41008 31.4 -80.87 2007 07 17 21 50 170 7.0 8.0

If using the Point Data window to define a colspan value, the numerical value must be in quotes. For example: colspan="2". This colspan value goes into the Extra field in the Point Data window.

Skipping columns

The "skip" parameter should be used to ignore (not read) values in the text file that shouldn't be used:
(recNum)->(Latitude, Longitude, Altitude, type(Text), time, turb_intensity)
time[fmt=yyyyMMddHH], obtime, skip, type(Text), skip, skip, Latitude, Longitude[scale=-1], Altitude[unit=ft], Altitude2[unit=ft], turb_intensity, skip
2004050100 0005    34     C210 1 T  38.82   92.22   7000   7000  0 -9
2004050100 0004    35     PA32 0 T  35.40   98.62   4000   4000  0 -9
2004050100 0008    58      A36 0 T  29.18   81.05   5000   5000  2 -9

Fixed values for several observations

If there are values (like time or location) that are fixed for several observations then this construct may be used:
(index) -> (Longitude,Latitude,Time,ST(Text),SPD,DIR,TD,T)
Longitude[unit="degrees west"],Latitude[unit="deg"],Time[fmt="yyyy-MM-dd HH:mm:ss z"],ST(Text),SPD[unit="m/s"],DIR[unit="deg"],TD[unit="celsius"],T[unit="celsius"]

2007-02-20 11:00:00 ST  ,0.0,0.0,8.9,13.3
2007-02-20 12:00:00 ST  ,0.0,0.0,11.9,15.0

2007-02-20 11:00:00 ST  ,1.5,160.0,-7.0,-2.0
2007-02-20 12:00:00 ST  ,1.5,160.0,-7.0,-2.0

2007-02-20 11:00:00 ST  ,10.8,230.0,-1.1,6.7

Loading into McIDAS-V

Finally, after the file has been created, McIDAS-V displays can be tailored in two ways:
  1. Create a layout model for those variables using the McIDAS-V's "Tools->Layout Model Editor" menu item.
Then, here is the process to read in and display the data:
  1. Use Data Source Type as "Text Point Data files"
  2. Use the "Point Data Plot" for the Display
  3. Select the newly created layout model

Using the Text Point Metadata Gui

If the text data does not have the metadata header lines the Text Point Data Source will show the following dialog which allows for specifying the metadata.
Image 1: Point Data Dialog Window
Image 1: Point Data Dialog Window


This field specifies how the different data values are separated within the text file. The options are Comma, Semicolon, Tab, and Space. Selecting this option allows McIDAS-V to separate out different text fields to allow for defining them at the bottom of this Point Data window.

Skipping lines

At the top, a number of the initial lines from the text data are shown. The arrow keys allow for specifying the start line. For example, if there were header lines in the file, these lines can be skipped over.

Specifying metadata
For each column of text data there is a row shown in the bottom of the dialog. This shows the sampled value and allows for entering a name, unit, date format, missing value and extra information. There are some names that McIDAS-V treats special: "Latitude", "Longitude", "Altitude", and "Time". At least Latitude, Longitude and Time must be specified in the file.

The Unit/Date Format field allows for specifying the Unit for data fields and the date format. For text fields choose Misc->Text as the unit.

The Extra fields must be of the form:

Don't forget the quotes!

Skipping columns
Certain columns can be skipped by entering the Name: "skip"

Saving this as a preference
To keep from having to enter in this data again next time new text point data of the same form is loaded, simply press the "Preferences" button and select Save Current. This allows for saving these metadata settings and reapply them later using the "Preferences" button.

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