Example:
select * from getbearings_mod('2004-09-27 00:00:00', '2004-10-08 0:00:00', -15000, null, 65) where aruid=1 order by bursttime, batch

Possibilities are:

- getbearings (two forms, with and without animal ID as an input param)

- getbearings_mod : Removes signals with high modulation values

- getbearings_smooth : Smooths groups of bearings

- getbearings_mod_smooth : Does both mod and smooth

All the above functions (except one of the getbearings functions) use the  
following input fields:

    StartTime   : Time of day to start bearing calculation
    EndTime     : Time of day to end bearing calculation
    noiselimit  : Minimum acceptable noise level (e.g. -13000).  Can be  "null".
    bearingtime : Time limit in seconds to use as a grouping value
                  (used since a burst may not give enough data).  Can be  "null".
    AnimalID    : Animal (i.e. radio tag) identifier




[[The function returns a field called "Bursts" (for want of a better name).   
This is a grouping variable that is controlled by the "Group time in  
Seconds" you select.  The longer the "Group time in Seconds" value, the  
more bearings that will be included in one "Burst".  Note this is  
different then the database bursts table data.  This is to compensate for  
data as it comes in at slightly offset time periods but where this same  
data is still part of one "bearing event" from a number of towers on one  
transmitter at one time period.]]