Data 144 (Crash GNSS Data)

Packets the GNSS data when the crash event is detected.

Note

This data is only used for Record 76H. If another record carries this data, its ‘Data Length’ will always be 0.

The frame format of the Data 144 unit is as follows:

For example (Total 158 bytes):
80 90 80 9A 00 20 00 0A 09 07 3C 46 FF 01 DB 88 57 5E 36 2F 50 00 06 09 07 3C 46 FF 01 DB 88 58 5E 36 2F 51 00 06 09 07 3C 46 FF 01 DB 88 59 5E 36 2F 52 00 06 09 07 3C 46 FF 01 DB 88 5A 5E 36 2F 53 00 06 09 07 3C 46 FF 01 DB 88 5B 5E 36 2F 54 00 06 09 07 3C 46 FF 01 DB 88 5C 5E 36 2F 55 00 06 09 07 3C 46 FF 01 DB 88 5D 5E 36 2F 56 00 06 09 07 3C 46 FF 01 DB 88 5E 5E 36 2F 57 00 06 09 07 3C 46 FF 01 DB 88 5F 5E 36 2F 58 00 06 09 07 3C 46 FF 01 DB 88 60 5E 36 2F 59 00 06

Parts	Fields	Length (Byte)	Range/Format	Default
ID	Data ID	2	8090H (144)	8090H (144)
Length	Data Length	1 or 2	00H-7FH or 8080H-84A8H
Content	Crash ID	1	00H-FFH
	Data Type	1
	Samples of 0.2Hz GNSS Data	1	00H-FFH
	Samples of 1Hz GNSS Data	1	00H-FFH
	0.2Hz GNSS Data	m
	1Hz GNSS Data	n

• Crash ID

  When the terminal detects a crash event, it will automatically assign a crash ID.

  The ID is convenient to distinguish multiple adjacent crash events. It rolls from 00H to FFH.

• Data Type

  Indicates the unit data type and the time point of recorded data, and so on.

  Details are as follows:

  • Reserved (Bit7)

    Reserved bit, set to 0b0 by default.

  • Unit Data (Bit6 to Bit4)

    • 0b010 - Mini Location. Please refer to the Data 81.

    • 0b011 - Full Location. Please refer to the Data 82.

    • Others - Reserved.

  • Reserved (Bit3 to Bit1)

    Reserved bits, set to 0b000 by default.

  • Time Point (Bit0)

    • 0b0 - The data is recorded before crash.

    • 0b1 - The data is recorded after crash.

• Samples of 0.2Hz GNSS Data

  Indicates the total number of unit data contained in the ‘0.2Hz GNSS Data’ field.

  If the value is 0, the ‘0.2Hz GNSS Data’ field is absent.

• Samples of 1Hz GNSS Data

  Indicates the total number of unit data contained in the ‘1Hz GNSS Data’ field.

  If the value is 0, the ‘1Hz GNSS Data’ field is absent.

• 0.2Hz GNSS Data

  GNSS data sampled at 0.2Hz (i.e. a set of unit data every 5 seconds).

  This field consists of one or more sets of unit data. The unit data is indicated by ‘Data Type’.

• 1Hz GNSS Data

  GNSS data sampled at 1Hz (i.e. a set of unit data every 1 second).

  This field consists of one or more sets of unit data. The unit data is indicated by ‘Data Type’.

  The unit data of “0.2Hz GNSS Data” or “1Hz GNSS Data” is defined as follows:

  • Unit Data is ‘Mini Location’ (0b010)

    Each unit data occupies 15 bytes. Please refer to the Data 81.

    Fields		Length (Byte)
    Mini Location	Fix State & Fix Mode	1
    	Longitude	4
    	Latitude	4
    	UTC Time	4
    	Speed	2

  • Unit Data is ‘Full Location’ (0b011)

    Each unit data occupies 22 bytes. Please refer to the Data 82.

    Fields		Length (Byte)
    Full Location	Fix State & Fix Mode	1
    	Longitude	4
    	Latitude	4
    	UTC Time	4
    	Speed	2
    	HDOP	1
    	Azimuth	2
    	Altitude	3
    	Satellite Count	1