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Bruce Flynn's avatar
Bruce Flynn authored
Replaced the merge code with something less efficient but easier to
grok.

New stream impl that does not read the data that will be used to create
and index used in new merge code.
7c6bd7fd
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# EdosL0Util
Tools for mangling EDOS L0 PDS files.

### Features:

    * API for streaming packets
    * CLI tools for:
        - merging multiple PDS files
        - splitting pds into X minute files
        - truncating files to specified time range
        - inspecting PDS info
    * Dumping JPSS H5 RDRs to L0 PDS files


### Packet streaming
To obtain a simple stream of packets, with support for secondary header
parsing use the ``PacketStream`` class as an iterator.

    >>> from edosl0util.stream import PacketStream
    >>> stream = PacketStream(open('P1570826VIIRSSCIENCEAS15286023813501.PDS'))
    >>> stream.next()
        <Packet apid=826 seqid=13072 stamp=2015-10-13 00:22:04.042798>
    >>> packets = list(stream)
    >>> first, last, info = stream.info()
    >>> print("First:{}\nLast:{}".format(first, last))
        First:2015-10-13 00:22:04.042798
        Last:2015-10-13 02:04:58.107582
    >>> print info
        defaultdict(<function edosl0util.stream.<lambda>>,
                {800: {'count': 32351, 'last_seqid': 16043, 'num_missing': 0},
                 801: {'count': 32351, 'last_seqid': 16043, 'num_missing': 0},
                 802: {'count': 32351, 'last_seqid': 16043, 'num_missing': 0},
                 803: {'count': 32351, 'last_seqid': 16043, 'num_missing': 0},
                 804: {'count': 32351, 'last_seqid': 16043, 'num_missing': 0},
                 805: {'count': 32351, 'last_seqid': 16043, 'num_missing': 0},
                 806: {'count': 59005, 'last_seqid': 2684, 'num_missing': 0},
                 807: {'count': 32351, 'last_seqid': 16043, 'num_missing': 0},
                 808: {'count': 59007, 'last_seqid': 2686, 'num_missing': 0},
                 809: {'count': 59007, 'last_seqid': 2686, 'num_missing': 0},
                 810: {'count': 32351, 'last_seqid': 16043, 'num_missing': 0},
                 811: {'count': 59007, 'last_seqid': 2686, 'num_missing': 0},
                 812: {'count': 59007, 'last_seqid': 2686, 'num_missing': 0},
                 813: {'count': 114543, 'last_seqid': 5214, 'num_missing': 0},
                 814: {'count': 59007, 'last_seqid': 2686, 'num_missing': 0},
                 815: {'count': 58994, 'last_seqid': 2673, 'num_missing': 0},
                 816: {'count': 58990, 'last_seqid': 2669, 'num_missing': 0},
                 817: {'count': 114510, 'last_seqid': 5181, 'num_missing': 0},
                 818: {'count': 62766, 'last_seqid': 11834, 'num_missing': 0},
                 819: {'count': 62766, 'last_seqid': 11834, 'num_missing': 0},
                 820: {'count': 62766, 'last_seqid': 11834, 'num_missing': 0},
                 821: {'count': 59007, 'last_seqid': 2686, 'num_missing': 0},
                 825: {'count': 83280, 'last_seqid': 3768, 'num_missing': 0},
                 826: {'count': 3471, 'last_seqid': 158, 'num_missing': 0}})

To handle ``PacketTooShort`` and ``NonSequentialSeqId`` errors you have to 
iterate manually:

    >>> from edosl0util.stream import PacketStream
    >>> stream = PacketStream(open('P1570826VIIRSSCIENCEAS15286023813501.PDS'))
    >>> while True:
       ...:     try:
       ...:         packet = stream.next()
       ...:         print(packet)
       ...:     except PacketTooShort as err:
       ...:         print("Corrupt packet stream: {:s}".format(packet))
       ...:         break
       ...:     except NonConsecutiveSeqId as err:
       ...:         print("Missing packet: {:s}".format(err))
       ...:     except StopIteration:
       ...:         break


### Command Line Tools
There are command line tools for merging, splitting, truncating and inspecting
L0 PDS files.

    * edosl0merge
    * edosl0split
    * edosl0trunc
    * edosl0info
    * rdr2l0


If you have quesions or comments related to this software contac
brucef@ssec.wisc.edu.