13 group channel bandwidth – gcbw chunk, 14 group centre frequencies – gcf_ chunk, 15 start of file header – sofh chunk – Wavecom PXGF streaming format (GEW) V1.24 User Manual

Page 15: 16 end of file header – eofh chunk, 17 text string – text chunk, Products

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Interface Requirement Specification for PXGF Streaming and File Format

3.4.13 Group Channel BandWidth – GCBW chunk

Element

Type

Description

iChannelBandwidth_uHz int64

The bandwidth of each channel contained in a GSIQ
chunk. Value stored in micro Hertz. It is assumed that
all of the channels are sampled at the same sample
rate, and therefore the bandwidth of all channels in the
group is equal.

Table 3.14: The GCBW chunk

3.4.14 Group Centre Frequencies – GCF_ chunk

Element

Type

Description

iNumChannels

int32

The number of channels in the group

alCentreFrequencies_uHz int64[iNumChannels] The centre frequency of each channel in micro

Hertz

Table 3.15: The GCF_ chunk

3.4.15 Start Of File Header – SOFH chunk

All files must be started with an instance of the SOFH chunk. The presence of this chunk can be used
to identify the file format as a PXGF file. For more information about what type of data is stored, the
remaining chunks before the EOFH chunk should be evaluated. This chunk must only appear once at
the start of a file.

Element

Type

Description

iFormat

int32

Identifier for the format used in a file. It is recommended that the
numeric value of the data chunk name used in the file be used for this,
e.g. SSIQ or GSIQ.

Table 3.16: The SOFH chunk

3.4.16 End Of File Header – EOFH chunk

This chunk must contain an empty data block, i.e. the size must be 0. It is used to indicate the end of
the header at the start of a file.

Element

Type

Description

Table 3.17: The EOFH chunk

3.4.17 TEXT string – TEXT chunk

Text chunk using ISO-8859-1 encoding. Each character is stored as a byte. This chunk can be used to
store meta data. It is suggested that this information appear in the header section of files. Text chunks
with different names could be created or meta data could be encoded in a single text chunk using
XML. See section 3.5.3 for a list of proposed text chunks.

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2009-01-13

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Page 14

Issue 1.24

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