rate_dataset::acquire_trk_rates

Source: dataset/rate/rate_dataset__acquire_trk_rates.pro

 rate_dataset::acquire_trk_rates
        Reads in the data from the TRK file and stores the appropriate parts 
        of it in the arrays rates and times.

 Call:
        code = dsref -> acquire_trk_rates(strnos)

 Return value:
        code    long    1 for success, 0 for failure

 Arguments:
        strnos  int     List of the streams which are to be read by
                        this invokation

 History:
        Hacked from ACQUIRE_UAV: 25/11/91; SJT
        Add checking of version numbers: 2/1/92; SJT
        Add use of MAP/SEEK: 17/1/92; SJT
        Make end times conform to time range: 30/1/92; SJT
        Fix bug in opening next file rules: 19/2/92; SJT
        Remove monitor toggle in widget-mode: 22/2/93; SJT
        Simplify and correct time differences: 8/6/93; SJT
        Spin off file handling to GET_LAN_RECORD: 13/8/93; SJT
        Add necessary code to allow error computation: 18/11/93; SJT
        Add accumulation of spacecraft position: 21/2/94; SJT
        Made into method of rate dataset: early 2000; SJT
        Removed idfref argument and redundant keys: 6/3/00; SJT
        Redo refcounts: 9/2/01; SJT