Structure of "Meteor-M" 2 satellite data
transmitted via L-band in direct broadcast mode


This section describes the structure of a signal that contains data from "Meteor-M" 2 satellite instruments. Data is transmitted in direct broadcast mode via L-band. Signal contains information from the following instruments:

  • MSU-MR scaner data
  • MTVZA microwave sounder data
  • information from data collection platforms (DCP)

Information from service equipment (on-Board Informational System - BIS-M), telemetry sensors and satellite clock is also included in the stream.

Signal is transmitted as a continuous sequence of phase-shift keyed “Manchester” code at 665.4 Kbit/s rate (transport rate is 1330.8 Kbit/s). Logical "1" is represented by symbol “10” (two bits), and logical "0" - by symbol "01" (two bits).

Data is packed into frames that are sent continuously one after another without intervals using time-division multiplexing. One frame consists of 1024 octets (bytes). Most significant bit of each octet comes first. The structure of information from service and scientific equipment, that is included in a transport frame is given in tables below.

Signals containing satellite clock data are included in the telemetry data stream. The structure of telemetry data stream is given in Table 2. Telemetry string length is 74 bytes. Telemetry data is contained in 2 bytes of a data frame (bytes 5 and 6), so to obtain a full string of telemetry data ground receiving station should accumulate telemetry data from an uninterrupted sequence of 37 data frames.

Data from MSU-MR scanner has its own structure, that is given in Table 4. Frames and strings of MSU-MR data are transmitted one after another without intervals.

Byte values in all data streams are given in decimal.


Table 1
Structure of a transport frame

Byte number Information Byte value Number
of bytes
1 Frame start marker
(32 bit PN sequence)
26 1
2 207 1
3 252 1
4 29 1
5, 6 Telemetry data 0...255 2
7...10 BIS-M data 0...255 4
11..14 SSPD data 0...255 4
1522 MTVZA data 0...255 8
23...260 MSU-MR data 0...255 238
261, 262 Telemetry data 0...255 2
263...266 BIS-M data 0...255 4
267...270 SSPD data 0...255 4
271...278 MTVZA data 0...255 8
279...516 MSU-MR data 0...255 238
517, 518 Telemetry data 0...255 2
519...522 BIS-M data 0...255 4
523...526 SSPD data 0...255 4
527...534 MTVZA data 0...255 8
535...772 MSU-MR data 0...255 238
773, 774 Telemetry data 0...255 2
775...778 BIS-M data 0...255 4
779...782 SSPD data 0...255 4
783...790 MTVZA data 0...255 8
791...1024 MSU-MR data 0...255 234


Table 2
Telemetry data frame structure

Byte number Information Byte value Number
of bytes
Comments
1 Sync-word
(64 bit PN sequence)
2 1  
2 24 1  
3 167 1  
4 163 1  
5 146 1  
6 221 1  
7 154 1  
8 191 1  
9 Telemetry cycle number 0...255 2 most significant word
10 0...255 least significant word
11 Channel number 0...255 1  
12 Satellite clock data 0...23 1 hours
13 0...59 1 minutes
14 0...59 1 seconds
15 Sync-word delay
relative to seconds
of the satellite clock. 

Sampling interval
~ 24 microseconds
0...255 2 most significant word
16 0...255 least significant word
17...26 Spare words   10  
27...55 Telemetry sensors data 0...255 29  
56...74 Spare words   19  


Table 3
Type "0" BIS-M frame structure

Byte number Information Byte value Number
of bytes
Comments
1 Sync-word (32 bit PN sequence) 113 1  
2 222 1  
3 44 1  
4 216 1  
5 Frame type 0 1  
6 Frame checksum 0...255 1  
7...10 Satellite clock time 0...255 4  
11...14 Satellite clock mode 0...255 4  
15...22

Satellite coordinates

0...255 8 Coordinate X
23...30 0...255 8 Coordinate Y
31...38 0...255 8 Coordinate Z
39...42 Satellite velocity 0...23 1 Velocity VX
43...46 0...59 1 Velocity VY
47...50 0...59 1 Velocity VZ
51...56 Spare words   6  
57...62 Time of aquiring last data on
angular velocity in this frame
0...255 6  
63...66 Angular velocities
(sensor #1 data)
0...255 4 Angular
velocity WX1
67...70 0...255 4 Angular
velocity WY1
71...74 Angular velocities
(sensor #1 data)
0...255 4 Angular
velocity WY2
75...78 0...255 4 Angular
velocity WZ2
79...82 Angular velocities
(sensor #1 data)
0...255 4 Angular
velocity WZ3
83...86 0...255 4 Angular
velocity WX3
87 Code word for angular
velocity sensors overall status
0...255 1  
88 Spare words   1  


Table 3a
Type "255" BIS-M frame structure

Byte number Information Byte value Number
of bytes
Comments
1 Sync-word (32 bit PN sequence) 113 1  
2 222 1  
3 44 1  
4 216 1  
5 Frame type 255 1  
6 Frame checksum 0...255 1  
7...10 Satellite clock time scale 0...255 4  
11, 12 STAT status word 0...255 2  
13...16

BOKZ-M star tracker
measurement time

0...255 4  
17...32

Location of body-fixed
coordinate system relative to
default coordinate system

0...255 16  
33...36 Time of satellite clock
status word generation
0...255 4  
37...38 Satellite clock
status word
0...255 2  

39...44

Time of aquiring last data
on pitch and roll from
vertical sensors
0...255 6  
45, 46 Pitch angle
(vertical sensor #1 data)
0...255 2  
47, 48 Roll angle
(vertical sensor #1 data)
0...255 2  
49, 50 Pitch angle
(vertical sensor #2 data)
0...255 2  
51, 52 Roll angle
(vertical sensor #2 data)
0...255 2  
53...56 Additional timestamps delay
relative to satellite clock
0...255 4  
57...62 Last angular velocity measurement time in this frame 0...255 6  
63...66 Angular velocities
(sensor #1 data)
0...255 4 Angular
velocity WX1
67...70 0...255 4 Angular
velocity WY1
71...74 Angular velocities
(sensor #2 data)
0...255 4 Angular
velocity WY2
75...78 0...255 4 Angular
velocity WZ2
79...82 Angular velocities
(sensor #3 data)
0...255 4 Angular
velocity WZ3
83...86 0...255 4 Angular
velocity WX3
87 Code word for angular
velocity sensors overall status
0...255 1  
88 Spare words   1  


Table 4
Structure of MSU-MR frame

Byte
number
Information Byte value Number
of bytes
Comments
1 Sync-word
(64 bit PN sequence)
2 1  
2 24 1  
3 167 1  
4 163 1  
5 146 1  
6 221 1  
7 154 1  
8 191 1  
9 Satellite clock data 0...23 1 hours
10 0...59 1 minutes
11 0...59 1 seconds
12 Sync-word delay
in reference to seconds
of the satellite clock. 
0...255 1
Sampling interval
~ 4 microseconds
13 Number of MSU-MR
unit and number of
active subsystem
xxxx 0000
xxxx 1111
1 xxxx - serial number
of unit
0000 - main subsystem
1111 - reserve subsystem
14 Data type marker 0 or 15 1 0000 0000 -
digital information
0000 1111 -
analog information
15...30 MSU-MR telemetry data 0...255 16  
31...35 Reserve 0...255 5  
36...50 Calibration signals 0...255 5  
51...11840 Video-information 0...255 11790  
11841
...
11850
Spare words   10  


Table 5
MTVZA frame structure

Byte
number
Information Byte value Number
of bytes
Comments
1 Sync-word
(32 bit PN sequence)
251 1  
2 56 1  
3 106 1  
4 69 1  
5...248 MTVZA data 0...255 244  


Table 6
SSPD frame structure

Byte
number
Information Byte value Number
of bytes
Comments
1 Sync-word
(24 bit PN sequence)
66 1  
2 187 1  
3 31 1  
4...15 Auxiliary data 0...255 12  
16...51 SSPD data 0...255 36  
52...63 Auxiliary data 0...255 12  
64...99 SSPD data 0...255 36  


Table 7
Structure of MSU-MR calibration data string

Byte number Value Comments
36 29WL1ch 28WL1ch 27WL1ch 26WL1ch 25WL1ch 24WL1ch 23WL1ch 22WL1ch Calibration signals brightness values
(10-bit encoding)

15 bytes
37 21WL1ch 20WL1ch 29BL1ch 28BL1ch 27BL1ch 26BL1ch 25BL1ch 24BL1ch
38 23BL1ch 22BL1ch 21BL1ch 20BL1ch 29WL2ch 28WL2ch 27WL2ch 26WL2ch
39 25WL2ch 24WL2ch 23WL2ch 22WL2ch 21WL2ch 20WL2ch 29BL2ch 28BL2ch
40 27BL2ch 26BL2ch 25BL2ch 24BL2ch 23BL2ch 22BL2ch 21BL2ch 20BL2ch
41 29WL3ch 28WL3ch 27WL3ch 26WL3ch 25WL3ch 24WL3ch 23WL3ch 22WL3ch
42 21WL3ch 20WL3ch 29BL3ch 28BL3ch 27BL3ch 26BL3ch 25BL3ch 24BL3ch
43 23BL3ch 22BL3ch 21BL3ch 20BL3ch 29CL4ch 28CL4ch 27CL4ch 26CL4ch
44 25CL4ch 24CL4ch 23CL4ch 22CL4ch 21CL4ch 20CL4ch 29HL4ch 28HL4ch
45 27HL4ch 26HL4ch 25HL4ch 24HL4ch 23HL4ch 22HL4ch 21HL4ch 20HL4ch
46 29CL5ch 28CL5ch 27CL5ch 26CL5ch 25CL5ch 24CL5ch 23CL5ch 22CL5ch
47 21CL5ch 20CL5ch 29HL5ch 28HL5ch 27HL5ch 26HL5ch 25HL5ch 24HL5ch
48 23HL5ch 22HL5ch 21HL5ch 20HL5ch 29CL6ch 28CL6ch 27CL6ch 26CL6ch
49 25CL6ch 24CL6ch 23CL6ch 22CL6ch 21CL6ch 20CL6ch 29HL6ch 28HL6ch
50 27HL6ch 26HL6ch 25HL6ch 24HL6ch 23HL6ch 22HL6ch 21HL6ch 20HL6ch




Table 8.
Structure of MSU-MR video-information string

Byte number Value Comments
51 291p1ch 281p1ch 271p1ch 261p1ch 251p1ch 241p1ch 231p1ch 221p1ch

Video-data

11 790 bytes

52 211p1ch 201p1ch 292p1ch 282p1ch 272p1ch 262p1ch 252p1ch 242p1ch
53 232p1ch 222p1ch 212p1ch 202p1ch 293p1ch 283p1ch 273p1ch 263p1ch
54 253p1ch 243p1ch 233p1ch 223p1ch 213p1ch 203p1ch 294p1ch 284p1ch
55 274p1ch 264p1ch 254p1ch 244p1ch 234p1ch 224p1ch 214p1ch 204p1ch
56 291p2ch 281p2ch 271p2ch 261p2ch 251p2ch 241p2ch 231p2ch 221p2ch
57 211p2ch 201p2ch 292p2ch 282p2ch 272p2ch 262p2ch 252p2ch 242p2ch
58 232p2ch 222p2ch 212p2ch 202p2ch 293p2ch 283p2ch 273p2ch 263p2ch
59 253p2ch 243p2ch 233p2ch 223p2ch 213p2ch 203p2ch 294p2ch 284p2ch
60 274p2ch 264p2ch 254p2ch 244p2ch 234p2ch 224p2ch 214p2ch 204p2ch
61

11840
... ... ... ... ... ... ... ...
                   

Comments for tabless 7 and 8:

  1. Most significant bits come first.
  2. Channels 1, 2, 3 are visible range and channels 4, 5, 6 are IR range.
  3. Each channel has 1572 10-bit pixels of the earth surface image.
  4. Bytes 36...11790 contain 10-bit words in the following encoding:
    2NWLLch Channel L white level, Nth bit, where 1≤L≤3 and 0≤N≤9.
    2NBLLch Channel L black level, Nth bit, where 1≤L≤3 and 0≤N≤9.
    2NCLMch Channel M Cold Black Body Level, Nth bit, where 4≤M≤6 and 0≤N≤9.
    2NHLMch Channel M Hot Black Body Level, Nth bit, where 4≤M≤6 and 0≤N≤9.
    2NXPYch Xth pixel of channel Y image, Nth bit, where 1≤X≤1540, 1≤Y≤6
    and 0≤N≤9.
  5. Video-information is transmitted in the following order:
    • 5 octets (4 pixels, 10 bits each) of channel 1
    • 5 octets (4 pixels, 10 bits each) of channel 2
    • 5 octets (4 pixels, 10 bits each) of channel 3
    • 5 octets (4 pixels, 10 bits each) of channel 4
    • 5 octets (4 pixels, 10 bits each) of channel 5
    • 5 octets (4 pixels, 10 bits each) of channel 6
    • next 5 octets (4 pixels, 10 bits each) of channel 1,
      etc.
  6. String length remains constant (11790 octets), strings come one after another, without intervals.
  7. Satellite clock data is transmitted as a 17-bit binary data.



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