Successful systems engineering requires a broad understanding of the important principles of modern satellite communications and onboard data processing. This course covers both theory and practice, with emphasis on the important system engineering principles, tradeoffs, and rules of thumb. The latest technologies are covered, including those needed for constellations of satellites. This course is recommended for engineers and scientists interested in acquiring an understanding of satellite communications, command and telemetry, onboard computing, and tracking. Each participant will receive a complete set of notes.

1. ATI's Satellite RF Communications
and Onboard Processing course
Instructors:
Eric Hoffman
Robert C. Moore
ATI Course Schedule: http://www.ATIcourses.com/schedule.htm
ATI's Satellite RF Communications: http://www.aticourses.com/satellite_rf_communications.htm

2. www.ATIcourses.com
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Riva, Maryland 21140
with On-Site Courses Telephone 1-888-501-2100 / (410) 965-8805
Tailored to Your Needs
Fax (410) 956-5785
Email: ATI@ATIcourses.com
The Applied Technology Institute specializes in training programs for technical professionals. Our courses keep you
current in the state-of-the-art technology that is essential to keep your company on the cutting edge in today’s highly
competitive marketplace. Since 1984, ATI has earned the trust of training departments nationwide, and has presented
on-site training at the major Navy, Air Force and NASA centers, and for a large number of contractors. Our training
increases effectiveness and productivity. Learn from the proven best.
For a Free On-Site Quote Visit Us At: http://www.ATIcourses.com/free_onsite_quote.asp
For Our Current Public Course Schedule Go To: http://www.ATIcourses.com/schedule.htm

3. EjH yt0509
2

4. Special Characteristics of Space Links
The satellite is constantly moving -
• Antennas must be constantly pointed
• Doppler shift complicates receiver design
Example:
∆f/f up to ± 25 ppm for LEO
satellites (± 50 kHz at S-band).
• Poor station coverage, short pass times
– continuous coverage would require hundreds of ground stations
– may need data storage
– special communications orbits (geostationary, Molniya)
– data relay satellite
3
EjH rj0424

5. The One-Way Radar Range Equation
(3 Forms)
PtGt A e
r
(GAIN-AREA) Pr =
4πR2
PtGtλ2Gr PtGtGr c2
(GAIN-GAIN) Pr = =
4πR24π (4π)2R2 f2
Pt4πAe Ae PtAe Ae f2
t r t r
(AREA-AREA) Pr = =
λ24πR2 R2 c2
4
EjH yt0521

6. Typical Radiation Pattern of a High-gain Antenna
●
●
●
5
EjH yt0521

7. Helix Antennas for MSX
and GPS Satellites
6
EjH yt0521
EjH yt1121

8. APL Hybrid Inflatable Antenna
Source: APL Technical Digest, Jan ‘03 7
EjH ye0706

9. 8
EjH yt0509

10. M-ary Phase Shift Keying (m = 8)
For Pε small,
Power Spectra
9
EjH yn0822

11. Sun Noise
10
EjH rj0422

12. Shannon’s Channel Capacity
• Consider a channel with bandwidth W and signal-to-noise ratio S/N.
• In 1948 Claude Shannon proved “there exist” codes and
modulations which permit error-free communication,
provided the bit rate does not exceed
S
C = W log2 ( 1 + )
N
Claude Shannon
• Do not use this upper bound for design! 1916-2001
• By letting N = No W and W ∞, can show that error-free digital
communication cannot take place below E/No = -1.6 dB (ln 2)
• High performance exacts a price: bandwidth spreading, abrupt
thresholds, complex coding/decoding equipment, computational delays
11
EjH ys0622

13. Prototype of Ball Aerospace’s TSAT laser comm terminal.
Structure and all 3 mirrors made from SiC. 1.55 micron
wavelength. Sat-to-sat at 40 Gbps.* 2.5 Gbps demo’d to
aircraft.
* transmit Encyclopedia Britannica in .025 sec
12
Ref: AW&ST 20 Nov 2006
EjH ys1218

14. 13
EjH yt1121

15. Supraluminal (faster-than-c) Communications
• Can a particle be accelerated to c?
• Can a particle have a velocity > c?
- Tachyons: how generate, modulate,
detect?
• Wormholes. Spacewarps through higher
dimensions.
• Would supraluminal communications violate the
Causality Principle?
References: “Particles That Go Faster Than Light,” Gerald Feinberg, Sci. Amer., 222, 2, Feb. 1970
Tachyon, http://en.wikipedia.org/wiki/Tachyon
Timescape, Gregory Benford, Simon & Schuster, 1980
A Brief History of Time, Steven W. Hawking, Bantam, 1988
“Faster than Light?” R. Y. Chiao et al, Sci Amer., Aug. 1993
Nine Crazy Ideas in Science, Robert Ehrlich, Princeton Univ. Press, 2001 14
“Time Travel,” Stephen Hawking, Discovery Channel, Apr 2010
EjH ra1015

16. Satellite “Tracking”
• Tracking: knowledge of satellite position and velocity (past, present,
and future).
• What are the tracking requirements and what drives them?
– orbit insertion (“quick look” orbit determination)
– precision orbit maintenance (e.g., 10 m)
– ground station “alerts”
– delayed commanding for future operations
– processing of data post facto
– satellite intercept and rendezvous
– satellite avoidance
– autonomous tracking required?
• Orbit perturbations can limit the ability to predict the future or
reconstruct the past. Perturbations may result from gravity
harmonics, drag, radiation pressure, Sun and Moon, maneuvers, etc.
Drag can be very unpredictable.
15
EjH gj0506

17. Typical NAVSPASUR
Fan-beam Antenna
16
EjH xu0405

18. 17
EjH gj0506

19. Maui Space Surveillance Site Atop
Mt. Haleakala (alt. 10,000 ft)
Air Force Maui Optical Station (AMOS)
Maui Optical Tracking and Identification
Facility (MOTIF)
Ground-based Electro-optical
Surveillance System (GEODSS)
18
EjH yt1120

20. Constellation Design
Things to think about . . .
• Size of coverage circle
• Dwell time over service area
• Repeatability of ground track
• Orbital perturbations
• Van Allen radiation belts
• Eclipse time
• Launch energy required
– altitude, inclination, eccentricity
• Minimum number of satellites
– how many planes?
– how many satellites per plane?
• Intra-sat comms and timing
• Sparing and replacement
19
EjH yt1124

21. AT
IM
AT w ate
I
M w ri
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
er w D rs ot
ia w o es D
l• w. N .c up
D AT ot
o Ic u D om lic
N ou pl
at
e
ot ic
w D rs a
es te
AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
er ou A at
w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
AT Ic ot ia
IM ou D l•
D
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler) TI lic
Ic N M at
ou ot
rs D at e
es up er
ia
.c lic
om a l
te
Encryption / Decryption Model
3

22. AT
IM
AT w ate
I
M w ri
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
er w D rs ot
ia w o es D
l• w. N .c up
D AT ot
o Ic u D om lic
N ou pl
at
e
ot ic
w D rs a
es te
AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
er ou A at
w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
AT Ic ot ia
IM ou D l•
D
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler) TI lic
Ic N M at
ou ot
rs D at e
es up er
ia
.c lic
om a l
te
End-to-End Command Flow
4

23. AT
M I
AT w ate
M I w ri
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
er w D rs ot
ia w o
SENSORS
es D
SELECTORS
l•
ACQUISITION
w. N .c up
CONVERTERS
D
CONDITIONERS
AT ot
o Ic u D om lic
N ou pl
at
e
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w D rs a
es te
AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
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w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
ia
STORAGE
AT Ic ot l•
PROCESSING
ou D
FORMATTERS
IM D
COMPRESSORS
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler) TI lic
Ic N M at
ou ot
rs D at e
es up er
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om a l
te
Spacecraft Telemetry System
ANTENNA
ENCODER
MODULATOR
5
TRANSMITTER
TRANSMISSION

24. AT
IM
AT w ate
I
M w ri
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
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l• w. N .c up
D AT ot
o Ic u D om lic
N ou pl
at
e
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w D rs a
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AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
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w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
AT Ic ot ia
IM ou D l•
D
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler) TI lic
Allan Deviation of
Ic N M at
ou ot
rs D at e
es up er
ia
.c lic
om a l
te
Precision Frequency Standards
6

25. e
e
at
at
lic
l
ia
om lic
up
er
.c up
at
D
Telemetry Multiple Access
es D
IM
ot
rs ot
N
om AT
ou N
o
Ic o
D
.c •
AT l • D
l
ia
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l•
er
rs a
ia
w. a
ic
at
• Frequency division multiple access (FDMA): different data on
om er
w ri
ou pl
M
w ate
.c at
Ic u
different sub-carrier frequencies
TI
D
es M
M
•A
AT ot
rs TI
• Time division multiple access (TDMA): a cyclic data frame is
I
AT
w. N
ou A
om te
defined in which different bit fields in the frame are assigned to
w o
Ic te •
.c ca
D
te
es li
different users
ca
l•
om a
rs up
.c lic
ia
w. li
ou D
w
w up
er
es up
• Code division multiple access (CDMA): coding techniques are used
AT
Ic ot
at
w D
rs D
AT N
to avoid interference between different users. Each different coding
M
ot
ou ot
o
N
I
Ic N
algorithm is decoded using a separate decoder (e.g., ±90º, ±180º phase
w. D
AT
o
AT o
w l•
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shift; orthogonal binary pseudo-random modulations; frequency-
D
ia
l•
w. •
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hopping)
w al
ia
at
w eri
er
w
IM
• Polarization division multiple access (PDMA): two signal sources
at
at
IM
AT
IM
use orthogonal polarizations of single carrier
AT
AT
• Space division multiple access (SDMA): spot-beam antennas
provide spatial separation of RF links
March 2004 Command / Telemetry / Data Processing (Sampler) 7

26. AT
M I
AT
w ate
M I
w ri
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
er w D rs ot
ia w o es D
l• w. N .c up
D AT ot
o Ic u D om lic
N ou pl
at
e
ot ic
w D rs a
es te
AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
er ou A at
w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
AT Ic ot ia
IM ou D l•
D
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler) TI lic
Ic N M at
Super-Commutation
ou ot
rs D at e
Sub-Commutation and
es up er
ia
.c lic l
They are sub-commutated in three successive minor frames.
om a
te
Data type 1 is super-commutated. It is sampled more than once in
each minor frame. Data types 2a, 2b, and 2c are sampled less often.
8

27. AT
IM
AT w ate
I
M w ri
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
er w D rs ot
ia w o es D
l• w. N .c up
D AT ot
o Ic u D om lic
N ou pl
at
e
ot ic
w D rs a
es te
AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
er ou A at
w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
AT Ic ot ia
IM ou D l•
D
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler) TI lic
Ic N M at
ou ot e
Structure of a Typical
rs D at
es up er
ia
.c lic
om a l
te
Packetized Telemetry Frame
9

28. e
e
at
at
lic
l
ia
om lic
Structure of a Typical Real-Time
up
er
.c up
at
D
es D
IM
ot
rs ot
N
Communications Bus Schedule
om AT
ou N
o
Ic o
D
.c •
AT l • D
l
ia
es te
l•
er
rs a
ia
w. a
ic
at
om er
w ri
ou pl
M
w ate
.c at
Ic u
TI
D
es M
M
•A
AT ot
rs TI
I
AT
w. N
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om te
w o
Ic te •
.c ca
D
te
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ca
l•
om a
rs up
.c lic
ia
w. li
ou D
w
w up
er
es up
AT
Ic ot
at
w D
rs D
AT N
M
ot
ou ot
o
N
I
Ic N
w. D
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o
AT o
w l•
D
D
ia
l•
w. •
er
w al
ia
at
w eri
er
w
IM
at
at
125 real-time slots, each 8 ms in duration
IM
AT
IM Instrument short data: 256-byte packets, 13 Hz maximum
AT
AT
Instrument long data: 1024-byte packets, 15 Hz maximum
Instrument command: 250-byte packets, 15 Hz maximum
RT reset (slot 58) occurs at 1/8 Hz (i.e., every 8 seconds)
March 2004 Command / Telemetry / Data Processing (Sampler) 10

29. AT
IM
AT w ate
I
M w ri
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
er w D rs ot
ia w o es D
l• w. N .c up
D AT ot
o Ic u D om lic
N ou pl
at
e
ot ic
w D rs a
es te
AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
er ou A at
w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
AT Ic ot ia
l•
System
IM ou D
D
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler) TI lic
Ic N M at
ou ot
rs D at e
es up er
ia
.c lic l
Spacecraft Data Processing
om a
te
12

30. AT
IM
AT w ate
I
M w ri
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
er w D rs ot
ia w o es D
l• w. N .c up
D AT ot
o Ic u D om lic
N ou pl
at
e
ot ic
w D rs a
es te
AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
er ou A at
w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
AT Ic ot ia
IM ou D l•
D
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler) TI lic
Ic N M at
ou ot
rs D at e
es up er
ia
.c lic l
Spacecraft Block Diagram
om a
te
13

31. AT
IM
AT w ate
I
M w ri
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
er w D rs ot
ia w o es D
l• w. N .c up
D AT ot
o Ic u D om lic
N ou pl
at
e
ot ic
w D rs a
es te
AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
er ou A at
w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
AT Ic ot ia
IM ou D l•
D
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler)
Block Diagram of
Ic N TI lic
ou ot M at
e
rs D at
Error-Correcting Logic
es up er
ia
.c lic
om a l
te
14

32. e
e
at
at
lic
l
ia
om lic
Earth-Orbit
up
er
.c up
at
D
es D
IM
ot
rs ot
N
Radiation Environment
om AT
ou N
o
Ic o
D
.c •
AT l • D
l
ia
es te
l•
er
rs a
ia
• Low altitude (200 – 500 km), low inclination (i ≤ 28°)
w. a
ic
at
om er
w ri
ou pl
M
w ate
.c at
– 100 – 1k rad(Si)/year. Design to 10k rad(Si)/year. Incident charged
Ic u
TI
D
es M
M
particles, Van Allen Belts, make SEUs an important concern at low
•A
AT ot
rs TI
I
inclination.
AT
w. N
ou A
om te
w o
Ic te •
• Low altitude (200 – 1000 km), high inclination (i > 28°)
.c ca
D
te
es li
ca
l•
– 1k – 10k rad(Si)/year. Design to 100k rad(Si)/year. More protons from
om a
rs up
.c lic
ia
w. li
ou D
Van Allen Belts, so use Adams ten percent worst case environment for
w
w up
er
es up
AT
Ic ot
SEU calculations.
at
w D
rs D
AT N
M
ot
ou ot
• Medium altitude (1000 – 4000 km)
o
N
I
Ic N
w. D
AT
– 100k – 1M rad(Si)/year. Design to 1M rad(Si)/year. Almost no
o
AT o
w l•
D
D
ia
geomagnetic shielding. Must use the most radiation-tolerant parts
l•
w. •
er
available.
w al
ia
at
w eri
er
w
IM
• High altitude (> 5000 km); e.g., geosynchronous (36,000 km)
at
at
IM
AT
IM
– 1k – 5k rad(Si)/year. Design to 50k rad(Si)/year. Spacecraft charging
AT
occurs as Earth’s magnetic field interacts with Solar wind, so SEU
AT
effects are dominated by the Adams ten-percent worst-case
environment.
March 2004 Command / Telemetry / Data Processing (Sampler) 15

33. AT
M I
w ate AT
M w ri I
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
er w D rs ot
ia w o es D
l• w. N .c up
D AT ot
o Ic u D om lic
N ou pl
at
e
ot ic
w D rs a
es te
AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
er ou A at
w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
AT Ic ot ia
IM ou D l•
D
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler) TI lic
Ic N M at
Systems (Box-level)
ou ot
rs D at e
es up er
ia
.c lic
om a l
Cross-Strapping Redundant
te
16
No single-point failure should be able to drag down both sides!

34. AT
IM
AT w ate
I
M w ri
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
er w D rs ot
ia w o es D
l• w. N .c up
D AT ot
o Ic u D om lic
N ou pl
at
e
ot ic
w D rs a
es te
AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
er ou A at
w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
AT Ic ot ia
IM ou D l•
D
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler) TI lic
Ic N M at
ou ot
rs D at e
es up er
ia
.c lic
om a l
te
Hot Tips for Flight Software
17

35. AT
IM
AT w ate
I
M w ri
AT at w. a
er AT l • D
March 2004
IM ia Ic o
at l• ou N
er w D rs ot
ia w o es D
l• w. N .c up
D AT ot
o Ic u D om lic
N ou pl
at
e
ot ic
w D rs a
es te
AT w up
w. li
ca .c •
IM AT om AT
at Ic te • IM
er ou A at
w ia rs TI er
w l• es M ia
w. D .c at l
AT N o om er
AT Ic ot ia
Hybrid
IM ou D l•
D
at rs up o
w eri
es li
.c ca N
w al ot
w. • om te D
AT o D •A up
Command / Telemetry / Data Processing (Sampler) TI lic
Ic N M at
ou ot
rs D at e
es up er
ia
.c lic
om a l
te
Image Compression Algorithm
18

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