NMC ON29 describes in detail the format for the upper air reports.
There are no longer any separate header records in these data files.
The first 10 characters of each record contain the year, month, day, and
hour (2x,4i2) of each observation and the original NMC record begins in the
11th character of the record.



Sample call to RDADP which returns the ID for next sequential report in
the file.

   10 CALL RDADP(IU,IDSRCH,IYR,IMO,IDY,IHR,IDSTYP,XLAT,XLON,
     2 ASTA,XHR,IC25,IC26,IC27,IRTYP,XELEV,IINTYP,LTH,ISTAT)



Excerpt from ON29 explaining the report ID variables (variable names added).

                                      APPENDIX B                                     |
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										       |
			REPORT IDENTIFICATION      (50 CHARACTERS)                     |
										       |
										       |
      ------------------------------------------------------------------------------   |
      Character|                   |                       |                           |
      Number(s)|   Parameter       |     Unit              |    Remarks                |
      ------------------------------------------------------------------------------   |
	       |                   |                       |                           |
XLAT    1 -  5 | Latitude *        | Hundredths of degree  |  Negative if in           |
	       |                   |                       |    So. Hemisphere         |
	       |                   |                       |                           |
XLON    6 - 10 | West longitude *  | Hundredths of degree  |  Values 00000 to          |
	       |                   |                       |    35999                  |
	       |                   |                       |                           |
ASTA   11 - 16 | Station           | Alphanumeric          |  Left justified,          |
	       |   identification %|                       |    blank fill             |
	       |                   |                       |                           |
XHR    17 - 20 | Observation time *| Hundredths of hour    |# Values 0000              |
	       |                   |                       |    to 2399                |
	       |                   |                       |                           |
       21 - 24 |$Reserved          | $ -----               |  $ -----                  |
	       |                   |                       |                           |
IC25        25 | 25th Character    | See description below |  see next page            |
	       |                   |                       |                           |
IC26        26 | 26th Character    | See description below |  see next page            |
	       |                   |                       |                           |
IC27        27 | 27th Character    | See description below |  see next page            |
	       |                   |                       |                           |
IRTYP  28 - 30 | Report type       | Character from        |  Always an integer        |
	       |                   |   Table R.1           |                           |
	       |                   |                       |                           |
XELEV  31 - 35 | Station           | Meter                 |  Negative if below        |
	       |   elevation *     |                       |    sea level              |
	       |                   |                       |                           |
IINTYP 36 - 37 | Instrument type * | Character from        |  Always an integer        |
	       |                   |   Table R.2           |                           |
	       |                   |                       |                           |
LTH    38 - 40 | Total length      | Number of             |    -----                  |
	       |   of report       |   ten-character words |                           |
	       |                   |                       |                           |
      ------------------------------------------------------------------------------   |
										       |
      * Whenever value is "missing" or not applicable, all characters for the          |
	  parameter will contain "9".                                                  |
										       |
      # From NMC ON124                                                                 |
										       |
      $ NMC ON124 shows "Receipt time" with same units and remarks as observation      |
	  time                                                                         |
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