Ascent Ground and Satellite Demonstration By Ray Roberge, WA1CYB & Howie DeFelice, AB2S WA1CYB s1
Ascent Ground and Satellite Demonstration
By Ray Roberge, WA1CYB
& Howie DeFelice, AB2S
WA1CYB s1
• Place more capable satellites into higher orbits
• Utilize software defined radios
• A programmable transponder that supports multiple linear and
non-linear (FM) conversations simultaneously
• Digital modulation support
• Multi-users SHARING the Output Power
• Downlink assumed to be in X band (10.45 GHz), or greater
• Real time Doppler compensation
Big Picture Goals
WA1CYB s2
• C-Band Uplink, X-Band Downlink (five and dime)
• Provide Frequency/Time Locking Capability for the Ground Station
• Utilize SDR technology to maximize flexibility to Experiment and Modify Operation
• Optimize Satellite architecture to minimize Ground Station costs
• Provide for maximum Power Weighting @Output for the downlink to prevent satellite capture
• UHF/VHF/L-Band/S-Band/HF optional Uplinks
• Provide a Digital Downlink of Satellite Data
• Provide a Digital Downlink of ID, Time stamp, Location (ala GPS/Grid Square) and uploaded TLE
• Provide for a DVB-S2 Input & Output when available
• Build in Redundant paths where feasible
• Provide multiple Digital Downlink paths
• Provide multiple Voice Downlink paths with different modulation types
• Provide a Multi-channel In- Single Channel out for contact Initiation and/or emergency channel
• Provide a controlled Ham Band Scanner Survey Downlink Capability
Current Focus Goals
WA1CYB s3
Build and Demonstrate an example Ground and Satellite system that gives the user
a sense of what a modern satellite system might look and feel like
Concentrate on the system, not the implementation
Talk to me about GNU Radio flow graphs at the demonstration area
Incorporate the latest technology that is available and cost effective
Use hardware and software that is identical or mimics planned future systems
Make the communication architecture programmable to facilitate experimentation
and optimization
Use COTS SDR(s) likely to be used to facilitate early launch opportunities
General Approach
WA1CYB s4
Demonstration Approach
Satellite Demo:
Use available ETTUS SDR (N210) instead of the E310 or B205 that is desired.
Use a laptop running GNU Radio software with UBUNTU Linux
GNU Radio SW is loaded internally in the E310 version, but we needed a display
Use a cheap RTL-SDR as the second satellite receiver
Ground Station Demo:
Use available ETTUS SDR (N210) instead of the E310 or B205 that is desired.
Use a laptop running GNU Radio software with UBUNTU Linux
GNU Radio SW is loaded internally in the E310 version, but we needed a display
Use a cheap RTL-SDR as the local receiver in place of a microphone input
WA1CYB s5
Ascent Demonstration- AMSAT Symposium
Uplink-1Receiver
DownlinkTransmitter
‘Satellite’ Computer• Receives Ground Station C-band• Demodulates Uplink signals,
both Digital and Analog• Cleans them up and weights
them for retransmission• Adds frequency/time lock signal• Adds any cmd downlink and msg• Transmits to Ground (Downlink)
DownlinkReceiver
Local Receiver added &Tuned to VHF/UHFFor this Demonstration Only
LNB
Ground Station Computer• Receives Local Transmissions• Converts Audio for uplink• Transmits Audio(s) to ‘Satellite’• Receives Sat Sim via X-band• Processes received Data stream• Locks Frequency• Selects output channel(s)
LocalReceiver
UplinkTransmitter
~10.3 GHz
~0.6 GHz
What should be inside the SDR
Uplink-2Receiver
~5.6 GHz
0.44, 1.26, 2.4, 3.4 GHz bands
0.145, 0.44, 1.26 GHz bands
0.4 to 4.4 GHz
0.145, 0.44, 1.26 GHz bands
WA1CYB s6
3U Satellite Demo Connection Diagram (Commo)
Satellite Simulator Computer
• Boot to UBUNTU LINUX• Ascent Folder• Demo on Desktop
• Runs GNU radio /GRC
Patch
Up-ConverterOscillator 6 GHz
~
ETTUS SDR (XMTR)
0.4 to 4.4 GHz
Charger
5V Wart
SMA
SMASMASMA
Ground Node Computer
• Boot to UBUNTU LINUX• Ascent Folder• SDR-ConsoleV3 for testing• Demo on Desktop
• Runs GNU radio /GRC• 38+ Frequency “Channels”
LNB
Speaker
Avenger LNB
RTL-SDR(Rcvr)
Charger
18V Wart
Type-F
Type-F
Wire
SMA toMCX
SMA Atten
SMA Cable
Type-F toSMA
Type-F Cable
Dual DC PowerInserter
V
V
H
H
10.0 – 10.4 GHz
Pwr Strip
Pwr Strip
ETTUS SDR (Rcvr)
ETTUS SDR (XMTR)
SMA toMCX
SMA Atten
LPA
LPA
DCBlock
Local Receiver
5V Wart
5V Wart
RTL-SDR(Rcvr)
SMA toMCX
SMA Atten
RTL-SDR(Rcvr)
Vert.
Vert.
LO = 9.75 GHz
6 m to 23 cm
6 m to 23 cm
10.0 – 10.4 GHz
5.65 – 5.67 GHz
250 – 650 MHz
AC Power
AC Power
0.4 to 4.4 GHz
WA1CYB s7
Example Downlink Frequency Band PlanArbitrary Peak Weighting
NB
FMUSBLS
B
Ton
e L
ock
ing
Car
rie
r
WB-Digital
PSK
31
PSK
31
USB
0-19 -9
-31
-32
-33
-35-37
-128kHz
-83
128kHz
-25
1. Tone Locking Carrier: Enables Ground Lock of Spectrum when Doppler is present2. NBFM: Voice Channel(s) Translated from a Low Band3. USB: Combined Multi-channel In Initiate contact and/or emergency channel down4. BPSK: ID, Telemetry and data stream from satellite5. CW: CW Bandwidth(s) Translated from a Low Band6. PSK31-3: Satellite broadcast of ID, Time stamp, Location (ala GPS) and TLE7. PSK31-2: Chat Channel #28. PSK31-1: Chat Channel #19. USB: Channel #310. LSB : Channel #411. Wide Band Digital: Channel #512. Location Pulse(s): Enables Precise Ranging/Location
-30
BP
SK
PSK
31 C
W
Tim
e
Location Pulse(s)
WA1CYB s8
As Seen at Avenger LNB Output(Noise in at 5.5 GHz, Few channels enabled, Sat Out at 10.45 GHz)
WA1CYB s9
Example Channel Breakdowns
FrequencyTranslateAnd Filter
FrequencyTranslateAnd Filter
FrequencyTranslateAnd Filter
FrequencyTranslateAnd Filter
SquelchAGCFrequencyTranslateAnd Filter
Wgt
Weighted Linear Channel
FilterCTCSS
SquelchAGC
SquelchAGC
FilterSquelchAGC
FrequencyTranslateAnd Filter
FrequencyTranslateAnd Filter
FrequencyTranslateAnd Filter
Wgt
Wgt
Wgt
NBFMRcvr
NBFMXmit
Weighted FM Channel
Weighted PSK-31 Linear Channel
9600BPSK
Demod
9600BPSKMod
Weighted 9600 BPSK
FrequencyTranslateAnd Filter
SquelchAGCFrequencyTranslateAnd Filter
Wgt
DVB-S2 FDM/TDM Channel
FilterFrequency
ChannelizerDemod /
ModTime
Multiplexer
WA1CYB s10
Demo Ground Station
Local ReceiverTuned to a ham band RTL: freq. <1300 MHz
LNB
Speaker
SDR-Rcvr.1
0.25->1.0 GHz
FDM Channel Select
SDR-Rcvr.2
SDR-Xmtr
FrequencyLock
Time Lock
Chat Display
10->10.5 GHz
9.75 GHz LO
Voce and Data Recorded Message s
0.4 to 4.4 GHzUplink
UHF/VHF/L-Band
FilterSquelchAGC NBFMRcvr
NBFMXmit
Freq. DivisionCombiner
Chat Channel Select
De modulation
FrequencyDisplay
WA1CYB s11
• 2nd receiver can be tasked to do other functions• Conduct an Amateur Frequency Survey (multi-bands)• Examine propagation via WSPR and WJT modes• Upper atmosphere scattering• Urban noise sources versus frequency etc.• Multiple frequency inputs on different bands with common output band channel
(Cross band input) for emergency use. “Hoot and Holler” Conference call• Shared Aperture Antenna Steering• Automatic logging of satellite users/peak signal level /vs satellite location• Very weak satellite transmitter power beacon experiments (no power amplifier,
straight SDR power)• Even more satellite input frequency receivers (1 chip for each 2 frequency bands)• Harmonic beacons for frequencies above x-band…… endless possibilities!
Amateur Radio Science Experiment Possibilities
~5 Minutes to Transfer 1 Complete Set of Measurements Using 1 Output Channel
WA1CYB s12
Go See the Demonstration!• The Following slides show in a series of 5 test builds what the satellite could do• If you want to build your own system, start with the simplest linear satellite (sat_test_1)• Git-hub site has all the sat_test flow diagrams• Helpful Notes contained in the flow graphs
Sat-test_1.grc• Linear repeater +/- 128 kHz w/ single agc and squelch • CW tone at the output center frequency , f0out
• ID (cw) at f0out – 30.5 kHz• Pseudo Doppler available (As if in LEO or higher orbit)
Sat-test_2.grc• Sat_test_1.grc capability plus• Added nbfm channel at receive center frequency, f0in
• Added nbfm output at f0out-9 kHz• Squelch shown set low, Noise in nbfm Channel only• Audio enabled for demo purposes
Sat-test_3.grc• Sat_test_2.grc capability plus• Shifted 128kHz of input to f0in-62.5 kHz
Sat-test_4_r3.grc• Sat_test_3.grc capability plus• 250 kHz noise shifted up 12.5 kHz and attenuated 100 dB• Added 32 (30 useable) linear channels (1.95 kHz bw)
• Output 30 channels at f0out-125 kHz to f0out-62.5 kHz• Added 8 input channels (7 useable) linear channels (7.81 kHz bw)
• Lower edge if the bank at f0out-13kHz, upper edge at f0out-59 kHz• Note that cw ID is also placed in the lower part of the 3rd filter from nbfm• Second receiver (SR2) enabled• Linear output of SR2 placed in the 1st filter from nbfm
Sat-test_5.grc• Sat_test_4_r3.grc capability plus• Adjusted nbfm bw on receive• Added three psk31 transmit streams, 1kHz apart , each with ID text
• Three placed in 4th 7.81 kHz linear channel at ~f0out-40 kHz• Placed another psk31 stream on a reduced output upper stream
• Output frequency just under f0out-125 kHz• Maxes out current external computer resource used for development
https://github.com/WA1CYB/satellite_ground_emulator/tree/master/Ascent/Concept%20Demo%20System WA1CYB s13
sat_test_1_0.png
Sat-test_1.grc• Linear repeater +/- 128 kHz w/ single agc and squelch • CW tone at the output center frequency , f0out
• ID (cw) at f0out – 30.5 kHz• Pseudo Doppler available (As if in LEO or higher orbit)
CW IDCD
Tone
Pseudo Doppler
TAB
WA1CYB s14
sat_test_1_1.png
Sat-test_1.grc• Linear repeater +/- 128 kHz w/ single agc and squelch • CW tone at the output center frequency , f0out
• ID (cw) at f0out – 30.5 kHz• Pseudo Doppler available (As if in LEO or higher orbit)
Pseudo Doppler set
to LEO
Equivalent Doppler Simulation for both Input and Output
WA1CYB s15
sat_test_2_0.png
Sat-test_2.grc• Sat_test_1.grc capability plus• Added nbfm channel at receive center frequency, f0in• Added nbfm output at f0out-9 kHz• Squelch shown set low, Noise in nbfm Channel only• Audio enabled for demo purposes
nbfmCarrier
WA1CYB s16
sat_test_2_1.png
Sat-test_2.grc• Sat_test_1.grc capability plus• Added nbfm channel at receive center frequency, f0in• Added nbfm output at f0out-9 kHz• Squelch shown set low, Noise in nbfm Channel only• Audio enabled for demo purposes
CW tone, cw ID and nbfmshifted w/ Doppler
Pseudo Doppler set
to LEO
WA1CYB s17
sat_test_2_2.png
Sat-test_2.grc• Sat_test_1.grc capability plus• Added nbfm channel at receive center frequency, f0in• Added nbfm output at f0out-9 kHz• Squelch shown set low, Noise in nbfm Channel only• Audio enabled for demo purposes
nbfmModulation
WA1CYB s18
sat_test_3_0.png
Sat-test_3.grc• Sat_test_2.grc capability plus• Shifted 128kHz of input to f0in-62.5 kHz
Squelch set to -58 dB
WA1CYB s19
sat_test_3_1.png
Sat-test_3.grc• Sat_test_2.grc capability plus• Shifted 128kHz of input to f0in-62.5 kHz
Squelch set to -64 dB
Max GainUpper Noise apparent
WA1CYB s20
sat_test_3_2.png
Sat-test_3.grc• Sat_test_2.grc capability plus• Shifted 128kHz of input to f0in-62.5 kHz
Squelch set to -64 dB
Gain reduced 3 dB (.707 voltage)
Upper Noise < squelch
WA1CYB s21
sat_test_4_0.png
Sat-test_4_r3.grc• Sat_test_3.grc capability plus• 250 kHz noise shifted up 12.5 kHz and attenuated 100 dB• Added 32 (30 useable) linear channels (1.95 kHz bw)• Output 30 channels at f0out-125 kHz to f0out-62.5 kHz• Added 8 input channels (7 useable) linear channels (7.81 kHz bw)• Upper edge if the bank at f0out-13kHz, lower edge at f0out-59 kHz• Note that cw ID is also placed in the lower part of the 3rd filter from nbfm• Second receiver (SR2) enabled• Linear output of SR2 placed in the 1st filter from nbfm
WA1CYB s22
sat_test_4_2.png
Sat-test_4_r3.grc• Sat_test_3.grc capability plus• 250 kHz noise shifted up 12.5 kHz and attenuated 100 dB• Added 32 (30 useable) linear channels (1.95 kHz bw)• Output 30 channels at f0out-125 kHz to f0out-62.5 kHz• Added 8 input channels (7 useable) linear channels (7.81 kHz bw)• Upper edge if the bank at f0out-13kHz, lower edge at f0out-59 kHz• Note that cw ID is also placed in the lower part of the 3rd filter from nbfm• Second receiver (SR2) enabled• Linear output of SR2 placed in the 1st filter from nbfm
Sat Receiver #2Signal received Spectrum shifted to
this output channel
WA1CYB s23
sat_test_4_3.png
Sat-test_4_r3.grcSat_test_3.grc capability plus250 kHz noise shifted up 12.5 kHz and attenuated 100 dBAdded 32 (30 useable) linear channels (1.95 kHz bw)Output 30 channels at f0out-125 kHz to f0out-62.5 kHzAdded 8 input channels (7 useable) linear channels (7.81 kHz bw)Upper edge if the bank at f0out-13kHz, lower edge at f0out-59 kHzNote that cw ID is also placed in the lower part of the 3rd filter from nbfmSecond receiver (SR2) enabledLinear output of SR2 placed in the 1st filter from nbfm
Spectrum shifted to this output channel
Zoomed in with greater resolution
WA1CYB s24
sat_test_4_4.png
Sat-test_4_r3.grc• Sat_test_3.grc capability plus• 250 kHz noise shifted up 12.5 kHz and attenuated 100 dB• Added 32 (30 useable) linear channels (1.95 kHz bw)• Output 30 channels at f0out-125 kHz to f0out-62.5 kHz• Added 8 input channels (7 useable) linear channels (7.81 kHz bw)• Upper edge if the bank at f0out-13kHz, lower edge at f0out-59 kHz• Note that cw ID is also placed in the lower part of the 3rd filter from nbfm• Second receiver (SR2) enabled• Linear output of SR2 placed in the 1st filter from nbfm
Pseudo Doppler set
to LEO
Expect +/- 250 kHz in 600 seconds, Demo scaled to 30 seconds
WA1CYB s25
sat_test_4_6.png
Sat-test_4_r3.grc• Sat_test_3.grc capability plus• 250 kHz noise shifted up 12.5 kHz and attenuated 100 dB• Added 32 (30 useable) linear channels (1.95 kHz bw)• Output 30 channels at f0out-125 kHz to f0out-62.5 kHz• Added 8 input channels (7 useable) linear channels (7.81 kHz bw)• Upper edge if the bank at f0out-13kHz, lower edge at f0out-59 kHz• Note that cw ID is also placed in the lower part of the 3rd filter from nbfm• Second receiver (SR2) enabled• Linear output of SR2 placed in the 1st filter from nbfm
Input Attenuation set to -20 dB, Squelch to -28 dB (so no nbfm)
Shows the six 7.8 kHz linear channels. One with
the cw ID added
Built in Test equipment Stack used.Wide Band Noise Applied to input
WA1CYB s26
sat_test_4_7.png
Sat-test_4_r3.grc• Sat_test_3.grc capability plus• 250 kHz noise shifted up 12.5 kHz and attenuated 100 dB• Added 32 (30 useable) linear channels (1.95 kHz bw)• Output 30 channels at f0out-125 kHz to f0out-62.5 kHz• Added 8 input channels (7 useable) linear channels (7.81 kHz bw)• Upper edge if the bank at f0out-13kHz, lower edge at f0out-59 kHz• Note that cw ID is also placed in the lower part of the 3rd filter from nbfm• Second receiver (SR2) enabled• Linear output of SR2 placed in the 1st filter from nbfm
Input Attenuation set to -20 dB, Squelch down to -51 dB
Upper linear Channel Bank now visible
WA1CYB s27
sat_test_5_0.png
Sat-test_5.grc• Sat_test_4_r3.grc capability plus• Adjusted nbfm bw on receive• Added three psk31 transmit streams, 1kHz apart , each with ID text• Three placed in 4th 7.81 kHz linear channel at ~f0out-40 kHz• Placed another psk31 stream on a reduced output upper stream
• Output frequency just under f0out-125 kHz• Maxes out current external computer resource used for development !
Shows three psk31 channels sharing one
7.8 kHz channel
Upper psk31 channel sharing one 1.95 kHz
linear channel
WA1CYB s28
sat_test_5_1.png
Sat-test_5.grc• Sat_test_4_r3.grc capability plus• Adjusted nbfm bw on receive• Added three psk31 transmit streams, 1kHz apart , each with ID text• Three placed in 4th 7.81 kHz linear channel at ~f0out-40 kHz• Placed another psk31 stream on a reduced output upper stream
• Output frequency just under f0out-125 kHz• Maxes out current external computer resource used for development!
Upper psk31 channel sharing one 1.95 kHz
linear channel
dB
WA1CYB s29
sat_test_5_2.png
Sat-test_5.grc• Sat_test_4_r3.grc capability plus• Adjusted nbfm bw on receive• Added three psk31 transmit streams, 1kHz apart , each with ID text• Three placed in 4th 7.81 kHz linear channel at ~f0out-40 kHz• Placed another psk31 stream on a reduced output upper stream
• Output frequency just under f0out-125 kHz• Maxes out current external computer resource used for development!
Shows three psk31 channels sharing one 7.8 kHz channel
- Better resolution -
Upper linear Channel Bank not visible,
Not breaking squelch
WA1CYB s30
sat_test_5_3.png
Sat-test_5.grc• Sat_test_4_r3.grc capability plus• Adjusted nbfm bw on receive• Added three psk31 transmit streams, 1kHz apart , each with ID text• Three placed in 4th 7.81 kHz linear channel at ~f0out-40 kHz• Placed another psk31 stream on a reduced output upper stream
• Output frequency just under f0out-125 kHz• Maxes out current external computer resource used for development! C
W ID
PSK
31
(s)
Upper linear Channel Bank not visible,
Not breaking squelch
WA1CYB s31
sat_test_5_4.png
Sat-test_5.grc• Sat_test_4_r3.grc capability plus• Adjusted nbfm bw on receive• Added three psk31 transmit streams, 1kHz apart , each with ID text• Three placed in 4th 7.81 kHz linear channel at ~f0out-40 kHz• Placed another psk31 stream on a reduced output upper stream
• Output frequency just under f0out-125 kHz• Maxes out current external computer resource used for development !
Upper psk31 channel sharing one 1.95 kHz
linear channel, zoomed in
WA1CYB s32
sat_test_5_5.png
Sat-test_5.grc• Sat_test_4_r3.grc capability plus• Adjusted nbfm bw on receive• Added three psk31 transmit streams, 1kHz apart , each with ID text• Three placed in 4th 7.81 kHz linear channel at ~f0out-40 kHz• Placed another psk31 stream on a reduced output upper stream
• Output frequency just under f0out-125 kHz• Maxes out current external computer resource used for development!
Squelch at -46 dBUpper linear channels noise over threshold
PSK31Visible
PSK31Visible
PSK31Not
Visible
WA1CYB s33
sat_test_5_6.png
Sat-test_5.grc• Sat_test_4_r3.grc capability plus• Adjusted nbfm bw on receive• Added three psk31 transmit streams, 1kHz apart , each with ID text• Three placed in 4th 7.81 kHz linear channel at ~f0out-40 kHz• Placed another psk31 stream on a reduced output upper stream
• Output frequency just under f0out-125 kHz• Maxes out current external computer resource used for development !
Squelch at -40 dBUpper linear channels noise under threshold
PSK31Visible
PSK31Visible
PSK31Visible
WA1CYB s34
Go See the Demonstration!
WA1CYB s35
Operational Procedure- rev AOperation of the Ground Station
1 Warm up receiver and LNB
2 Run Frequency Calibration using ATSC pilots (Resulting error between 500 and 650MHz is less than 100 Hz
3 Turn GS receiver on SDR w/ LNB), input offset if needed
4 Turn GS C-band transmitter at known frequency and look for 2nd Harmonic in GS receiver SDR w/ LNB)
5 Measure Offset error and save, This is the LNB error + transmitter error + corrected SDR receiver error (GS error). Restart if required
6 Wait for Satellite, monitor beacon frequency range
7 After CW/Range beacon is visible, Center manually on the display. This is the GS error+ Satellite error + Doppler + Satellite frequency error
8 Subtract the GS error in step 5 from the measured frequency in step 7. This is the Satellite error + Doppler + Satellite frequency error
9 Turn on the Satellite error + Doppler + Satellite frequency error lock circuit
10 All receiver channels should be locked to the satellite and track it within +/-250Khz (LEO X-band)11 Transmit with selected offset (channel) on a unused channel12 Verify receiver picks up transmitter on frequency translation to X-Band.13 Antenna Rotation Control not demonstrated (this time)
Operation of the Satellite Station1 Warm up SDRs (Receiver and Transmitter)2 Bypass command structure and turn on system manually3 Enable CW/Range Beacon
4 Enable C-band receiver Band5 Enable Transmitter
System Operation Verification1 Use HT to talk to ground station on Channel zero
2 Verify reception on Channel zero on the Ground Station at X-band
WA1CYB s36