pyall

• created: August 2016
• version 1.50
• by: p.kennedy@fugro.com
• description: python module to read an Kongsberg .ALL file
• notes: See main at end of script for example how to use this
• based on ALL file version October 2013
• developed for Python version 3.4

Done

• Added A_Attitude decode
• Added n_Attitude network attitude decode
• Added method to read rawbytes for an entire datagram including header. This is needed to exclude datagrams when conditioning files.
• Added functionality for 'U' UNKNOWN_RECORD so we handle all records in an identical manner
• Added functionality to return 'data' property for each class so we can access raw bytes
• Added decode for N (travel time) records
• Added backward support for python 2.7. Needed to add support for timestamp as this was only availble in python 3.4
• Added error trap for reading a corrupt .all file
• Added support for I installation datagram into a key/value pair
• Added loadnavigation method which reads all nav into a list
• Trialled some struct speed-ups. no success
• Patched D decode to simplify and repair missing field (maxbeams)
• Patched print statement for python 3.x instead of only python 2.x
• Added read for trailing bytes in 'P' records for M3 sonar which appears to write imperfect records
• now read the full 5 fields in the header so we can access the record time. then resent the pointer so the full record can be read and parsed. This would appear to be IO inefficient, but it is not as the OS buffers 4 k when reading
• Basic read loop is in place. reads datagram header and skips to next record. THis is quick
• P = 80 P Position record decode in place
• X = 88 X depth record decode in place. Beam data is in a list of depths[], alongtrack[] etc instead of a beam object. This may be more efficient?
• Tested X reader by making a waterfall image. Results look good

2Do

E = 69 F = 70 G = 71 H = 72 I = 73 J = 74 K = 75 L = 76 M = 77 O = 79 Q = 81 R = 82 S = 83 T = 84 U = 85 V = 86 W = 87 Y = 89

Example Reader

    r = allreader("C:/development/all/sampledata/EM2040/GeoFocusEM2040400kHzdual-Rx0.5degx1degPitchStabilised.all")
    start_time = time.time() # time the process

    while r.moreData():
        # read a datagram.  If we support it, return the datagram type and aclass for that datagram
        # The user then needs to call the read() method for the class to undertake a fileread and binary decode.  This keeps the read super quick.
        TypeOfDatagram, datagram = r.readDatagram()

        if TypeOfDatagram == 'P':
            datagram.read()
            print ("Lat: %.5f Lon: %.5f" % (datagram.Latitude, datagram.Longitude))

        if TypeOfDatagram == 'X':
            datagram.read()

    print("Read Duration: %.3f seconds" % (time.time() - start_time)) # print the processing time. It is handy to keep an eye on processing performance.

    r.rewind()
    print("Complete reading ALL file :-)")
    r.close()    
    # see the test code in main() at the end of pyall for more details.  Have Fun

Data Type Conversions from ALL to Python::     
    * ALL types to python struct types
    * signed char = 1 byte = "b"
    * unsigned char = 1 byte = "B"
    * XTFWORD = signed int 2 bytes = h
    * XTFWORD = UNsigned int 2 bytes = H (for unipolar data)
    * DWORD = unsigned int 4 bytes = "L"
    * short = short integer 2 bytes = "h"
    * char = 1 byte = "c"