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Last modified 15 April 2004

A tutorial on using this version of isprint on the web

This version of isprint on the web allows you to display data from a single madrigal file, which consists of a number of records.  There are three steps you'll need to do to use this page:
  1. Choose what data in the file you wish to filter out using the "Available Filters" section.
  2. For the remaining data, you then need to choose which parameters to display, using the "Available Parameters" section.
  3. Finally, set up how you want the output formated.

Saved filters/parameters

With this version of isprint on the web, you can also use a saved filter to apply all these settings to a different madrigal file.  When you apply a saved filter, all your selections from the three tasks above (filtering, selecting parameters, and output formatting) are automatically applied.  The only input not affected by applying a filter is the start and stop dates, since these will always change from file to file.  Note that the times of day are saved and applied when using a saved filter.

Logging in or out

If you want to save your own filter, you'll need to log in.  There's no special permission needed to create a new login, anyone can create a new login at any time.  When you login, you can save your filters to your own directories.   Each directory you create will either be public or private.  If you make a public directory, everyone will be able to use the filters you store in that directory.  If you make a private directory, only you will be able to use the filters stored in that directory.   Whether public or private, only you will be able to delete your own filters and directories.

When you log in, this version of isprint will write a cookie to your browser so you will be automatically logged in when you visit this Madrigal database site again.  This automatic login will last up to one year before you need to log in again, depending on the number of cookies on your browser.  For the normal user, there is no need to login and/or logout whenever you leave or enter the site.  If you do not want that to happen, you have two choices: 1) choose "No automatic login".  This will cause your cookie to be automatically deleted when you leave the site.  2) Choose "Logout" when you are done using this new version of isprint on the web.  This will immediately delete your cookie.  You will need to log in again to access your private filters, and to save any type of filter.

Filtering out data

The purpose of the "Available Filters" section is to allow you to only display the madrigal data you want to include.  Almost all the filters in this section use the idea of a range:  if a given parameter is outside of the set range, it is excluded.  At the moment this is the only type of data filter available.  To simulate only having a minimum or maximum value, simply set the other end of the range to be blank.  For example, to see all data with an elevation over 20 degrees, set the minimum to 20 and leave the max blank.  The exceptions are the kindat (or kinst) filters.  These allow either all kindat (or kinst) values to be selected, or a single value.

There are now also free-form filters at the end of the filter section, which allow you to set up filters based on any single parameter shown on this page or on two parameters either added, subtracted, multiplied, or divided together.

The date/time filter allows you to set a start and stop time for the data.  By default when the data loads, the start date/time is set to the beginning of the file, and the end date/time is set to the end of the file.  Note that if you use these defaults, you may get a very large amount of data that will take some time to process.  The start and end dates are required fields, so they have no default values.  The start time will default to 0:0:0 (the beginning of the day) if you blank out any of the start time fields.   The end time will default to 24:0:0 (the end of the day) if you blank out any of the end time fields.

Note that a madrigal record is made up of both 1D and 2D parameters.  When a 1D parameter such as azimuth is used to filter data, entire records are excluded when outside of the range.  When a 2D parameter such as altitude is used to filter data, only those 2D data from the record outside the given range are excluded.

Only filters relevent to a given data set will be displayed.  If a file has no pulse length data, the pulse length filter will not appear.  If there is only one kind of data (kindat), that filter will not appear.

If you do not want to use a filter, simply blank out any of the entries, and it will be ignored.  For the most part, the default settings when the file loads will allow all data.  The only exceptions are the altitude and pulse length filters.  The default maximum value of the altitude and pulse length filters are the maximum data found in the file with valid measurements (plus 0.01 km or 0.1 microsecond to include endpoint).  In this case valid measurement means any data found with any real error measurements.  For example, if all data in the file with an altitude above 1058 km has all error measurements set to -32767 (invalid data), then the default value of the maximum altitude when the file is loaded will be 1059 km.  You can set the filter higher than this default to view the higher data.

Azimuth filters

Azimuth filters work slightly different than the other filters, in that azimuth represents a circular range. Azimuths are restricted to -180 to 180 degrees. The range always moves in a clockwise direction from lower limit to upper limit. This means that the range will go through 180 degrees if you specify a range with the lower limit greater than the upper limit, such as 170 to -170 degrees. The range 170 to -170 will accept any azimuth between 170 and 180 or between -180 and -170. Azimuth is the only filter where setting the lower limit to be greater than the upper limit will not eliminate all data.

Date/time filter

Filter
Value when file first loaded
Default  if set to blank
Start Date First day of file Cannot be empty
Start Time Time of first record 00:00:00 
End Date Last day of file Cannot be empty
End Time Time of last record 24:00:00
Date/time filtering

Other filters

Filter
Minimum when file first loaded
Maximum when file first loaded
Altitude 0 Maximum valid altitude found in file (see above)
Azimuth 0 360
Additional azimuth 0 0
Elevation 0 90
Additional elevation 0 0
Pulse length (microseconds) 0 Maximum pulse length found in file
Kind of instrument (kinst) All -
Kind of data (kindat) All -
List of other filters used to exclude data

Using free form filters

Also available is a way for you to filter data based on any parameter or parameters listed on this page. The place to input these free-form filters looks like this:
Mnemonic (or Mnem1 +,-,*,/ Mnem2) (example: gdalt or gdalt - sdwht) Leave spaces between mnemonics and operator Lower limit (leave blank if none) Upper limit (leave blank if none)
These filters work as follows: The first filter implies "gdalt - sdwht" must be greater than 0.0. Since sdwht is shadow height (the distance above any point on the earth where the sun is first visible), this filter implies that only data in direct sunlight will be displayed. The second filter says that BMAG (the magnitude of the magnetic field) must be between 0 and 3e-5 Telsa. Note that the meaning and units of any parameter are available by clicking on them.

Note that the filter can be based on any single parameter (such as BMAG above), or any two parameters either added, subtracted, multiplied, or divided (as in the "gdalt - sdwht" example above). Leaving either the lower limit or the upper limit blank means there will be either no lower limit or no upper limit. Leaving both blank means the filter is ignored. Note that if the parameter you enter is missing or cannot be calculated, it will be rejected no matter what the range is, since missing data is never in any range.

How are filters combined?

In general, all these separate filters are and'ed together, so if data is excluded from any filter it is excluded.  With this new version of isprint on the web, there are now two exceptions: additional azimuth range, and additional elevation range.  The purpose of these two new filters is to provide a little more flexibilty in filtering azimuth or elevation than can be provided by a simple range.  For example, if you wanted to select azimuth values between 270 and 30 degrees, the simple range approach would not work, since the range does not go through zero.  The additional azimuth range added in this release allows this now to be done.  The two azimuth ranges are or'ed together: a record is selected if its azimuth is in either range.  Elevation works the same way.  By default, the additional azimuth and elevation ranges are set to 0 to 0 degrees, so they have no effect on the filter and can be ignored if not needed.

Example 1:

If you set your filter values as follows:
 
 
Filter
Minimum
Maximum
Date July 4, 1995 (Start date) July 5. 1995 (End date)
Time 23:00:00 (Start time) 1:00:00 (End time)
Altitude 200 500
Azimuth 270 360
Additional azimuth 0 90
Elevation 10         
Additional elevation 0 0
Pulse length 0         
Kind of instrument (kinst) Millstone Hill Steerable Antenna -
List of potential filters used to exclude data
In order to be displayed, data would have to:
  • be between July 4, 1995 at 23:00:00 and July 5, 1995 at 1:00:00
    • AND
  • be between 200 km and 500 km in altitude
    • AND
  • have an azimuth between 270 and 360 OR between 0 and 90
    • AND
  • have a kinst = "Millstone Hill Steerable Antenna"
The elevation filter is ignored since the maximum elevation is blank.  This is the same as setting the elevation filter from 0 to 90, and so the additional elevation filter is irrelevant.  The pulse length filter is also ignored since the maximum pulse length is blank.  The Kind of data filter does not even appear since the example file had only one kind of data.
 

Example 2:

If you set your filter values as follows:
 
 
Filter
Default minimum
Default maximum
Date July 5, 1995 (Start date) July 5, 1995 (End date)
Time 10:00:00 (Start time)                 (End time - at least one field blank)
Altitude 200        
Azimuth 270 360
Additional azimuth 0 90
Elevation 10 20
Additional elevation 70 80
Pulse length 500 100000
Kind of instrument (kinst) All -
List of potential filters used to exclude data
In order to be displayed, data would have to:
  • be between July 5, 1995 at 10:00:00 and July 5, 1995 at 24:00:00
    • AND
  • have an azimuth between 270 and 360 OR between 0 and 90 degrees
    • AND
  • have a elevation between 10 and 20 OR between 70 and 80 degrees
    • AND
  • have a pulse length between 500 and 100000 microseconds
Since no complete end time is entered, it defaults to 24:00:00.  No filtering is done by altitude since there is at least one blank - the minimum value of 200 km is ignored.  No filtering is done by kinst since "All" is selected.
 

Selecting parameters to display

Beneath the "Available Filters" section is the "Available Parameters" section.  This section lists the mnemonic codes for the parameters available for display.  They are grouped by the Cedar categories as defined in the Cedar standard.  To see a pop-up description of any particular parameter, click on its mnemonic.   To see a listing of all available parameters and their descriptions, click on the "Description of parameters" link.  Parameters shown in bold are those actually found in the madrigal file.

When you save a filter, the list of selected parameters is also saved.  When you apply this filter later, these parameters are automatically selected if they are available.  Note that no warning is given if you apply a filter with a certain parameter selected that doesn't exist in the new file - that parameter is simply ignored.

Formatting the output

The final section of this web page allows you to modify how your records will be displayed.

Headers off

Selecting this checkbox will cause the data to be displayed as a single table, with the parameters labled only in the very first row.   If not selected (the default), parameters are labled at the beginning of each new record.

Bad value string

This text box allows you to enter a new string to indicate a bad value in the output.  The default is "missing"

Maximum characters per row (50 - 9999)

This text box allows you to set the maximum number of characters in each row of the output within the range of 50 characters to a maximum of 9999 characters.  The default is the maximum, 9999 characters.
 

Final notes

Please feel free to send any comments or suggestion to Bill Rideout at MIT Haystack.

This web application is built on top of a command line application called "isprint" installed in the madrigal bin directory.  If you'd like to use the command line application instead, the instructions can be found here.