Data Format Descriptions

DRX

DRX data consist of a time series of complex data sampled at fS / Decimation Factor from the beamformer. The data are divided into packets of 4096 samples per beam per tuning per polarization.

Note

Fields are big endian

Byte(s)

Name

Description

0-3

Sync Word

0xDECODE5C

4-6

Frame Count

Always zero

7

ID

Packed frame source ID

8-11

Second Count

Always zero

12-13

Decimation Factor

Decimation factor of fS

14-15

Time Offset

Time correction to the time tag

16-23

Time tag

Time tag [1]

24-28

Flags

Always zero

29-31

Tuning Word

Tuning frequency [2]

32-4127

Data

ci4 data - [time,]

The packing on the ID field is:

Bit(s)

Description

0-2

Beam

3-5

Tuning

6

Always zero

7

Polarization

The ci4 aka “4+4-bit complex integer” data are stored as two’s complement integers with the real part stored in the first four bits of the byte.

DR Spectrometer

DR Spectrometer data contain DRX data that has been transformed to the Fourier domain, converted to power, and integrated on-the-fly by the data recorder. The format allows for variable integration times, channel counts, and polarization products to be stored.

Byte(s)

Name

Description

0-3

Magic Word 1

0xC0DEC0DE

4-11

Time tag

Time tag of first frame [1]

12-13

Time offset

Time correction to the time tag

14-15

Decimation Factor

Decimation factor of fS

16-23

Tuning Word[2]

Tuning frequencies [2] [3]

24-39

Fills[4]

Fill counts [4]

40-43

Errors[4]

Error flags [4]

44

Beam

Beam

45

Stokes Format

Polarization format code

46

Version

Packet format version

47

Flags

Bit flags

48-51

Nfreq

Transform length [5]

52-53

Nint

Integration count [5]

54-67

Sats[4]

Saturation counts [4]

68-71

Magic Word 2

0xED0CED0C

72-N

Data

float data - [pol,chan]

The Stokes Format is a bit field that defines what polarizations are included in the packet data. The fields are:

Value

Pol. Product

0x01

XX*

0x02

Real(XY*)

0x04

Imag(XY*)

0x08

YY*

0x10

I

0x20

Q

0x40

U

0x80

V

The data are stored as little endian float values.

TBX

TBX is a complex frequency-domain product that contains blocks of up to 16 channels from all stands and polarizations. Each channel has a bandwidth of fC (25 kHz) and there may be up to 224 different values of First Channel within a single recording. The stand ordering is based on the input into the digital system rather than the stand number in the array.

Note

Fields are big endian

Byte(s)

Name

Description

0-3

Sync Word

0xDECODE5C

4-6

Frame Count

Frame number within capture

7

NDP ID

Always 0x08

8-11

Second Count

Always zero

12-13

First Channel

First channel in packet

14-15

Unassigned

Always zero

16-23

Time tag

Time tag [1]

24-N

Data

ci4 data - [chan,stand,pol]

The ci4 aka “4+4-bit complex integer” data are stored as two’s complement integers with the real part stored in the first four bits of the byte.

COR

The COR format contains full polarization complex visibility data for 132 channels from a single baseline pair. Each channel has a bandwidth of fC (25 kHz) and there may be up to six different contiguous values of First Channel within a single recording. The stand numbering for the baseline pair is based on the input into the digital system rather than the stand number in the array.

Note

Fields are big endian

Byte(s)

Name

Description

0-3

Sync Word

0xDECODE5C

4-6

Frame Count

Server ID

7

NDP ID

Always two

8-11

Second Count

Always zero

12-13

First Channel

First channel in packet

14-15

Gain

COR gain used

16-23

Time tag

Time tag [1]

24-27

Navg

Integration time in samples

28-29

Stand 1

First stand in baseline

30-31

Stand 2

Second stand in baseline

32-4255

Data

Complex<float> data - [chan,pol1,pol2]

The data are stored as little endian Complex<float> values.