VHF SATELLITES

1
VHF SATELLITES
Gregor Poar, S53RA
Whitton Amateur Radio Group, London 16. March 2007
2
VHF SATELLITES - definition by S53RA -)
satellites that can be heard on VHF - not about
amateur satellites, neither about military sats
in 200-400 MHz band - almost all in Low Earth
Orbit (LEO) - 400-3000 km, usually abt. 800-900
km above ground
above GEO satellite
left LEO satellites
3
TOOLS - FM and SSB VHF (136-180 MHz)
receiver - PC with soundcard, audio cable -
Software (free downloadable) satellite tracking,
spectrogram,... - satellite tracking -
SatScape (G4ILO) - frequency vs time graphs
(waterfall) - SpectrumLab (DL4YHF) - weather
image decoding - WXtoIMG weather
images SIGNALS - non-modulated carriers
(beacons) - some kind of telemetry -
navigational data - WX APT images - power from
miliwatts to a couple of watts.
4
Satellite tracking software - SatScape screenshot
5
Audio spectrum analyzer software Spectrum Lab
screenshot time vs frequency
diagram (SSB mode)
Time
Doppler Shift satellite signal easily
recognizable, heard as a falling tone or viewed
as (a section of) the Doppler curve (-3kHz on
VHF).
6
Most satellites can be received with fairly
simple equipment Example of a station setup in a
hotel in Central London
My equipment - Yaesu FT-100d - Kenwood TH-28 -
Laptop with Satscape and SpectrumLab
Software - Hand-held VHF antenna on a window
7
NOAA Weather Satellites - National Oceanic
Atmospheric Administration - polar satellites
(inclination near 90 deg.) - a flypast takes abt.
15 minutes - transmiting on SHF (1,6 GHz) and
also on VHF - VHF 137 MHz FM APT WX image and
beacon/telemetry data - similar to SSTV, scanning
line after line, continous transmission, 5W -
transmits two channels (two pictures), visible
light and infrared - bandwidth 36 kHz not
suitable for commercial HAM receivers - dedicated
receivers, top-line scanners (AoR5000), home-made
receiver - with limitations a HAM FM radio can be
used to some point NOAA 12 137,500 APT,
136,770 beacon/telemetry NOAA 14 APT
N/A, 137,770 beacon/telemetry NOAA 15
137,500 APT, 137,350 beacon/telemetry NOAA
16 APT N/A, 137,770
beacon/telemetry NOAA 17 137,620 APT,
137,350 beacon/telemetry NOAA 18 137,910
APT, 137,350 beacon/telemetry - WXtoIMG
software (free)
8
Improvised setup - Kenwood TH-28e and a 2m GP
antenna
9
Example of a received WX image - visible light
channel - some noise fading (GP antenna) -
cca. 15 minutes
10
Both channels displayed - channel A (left) -
visible light - channel B (right) infrared -
bandwidth limitations
11
NOAA beacon/telemetry - heard on 136,770
137,350 137,770 MHz - either non-modulated
carrier or telemetry (-8kHz, 8320bps, PSK
Split-Phase, TIP-Tiros Information Processor) -
power 0,5 or 1 W
12
OTHER WEATHER SATELLITES ON VHF - METOP-A, a new
European WX LEO satellite - Similar in function
to the NOAA satellites, more sophisticated -
Launched in autumn 2006 - Reported healthy on all
systems - Should be transmitting on VHF also
(137,100 MHz) - Russian Meteor, Okean, Resurs
and similar (137 MHz) - None heard, probably
malfunctioning or dead - Chinese Feng-Yun -
Feng-Yun 1C and 1D heard at 180,006 and 180,007
MHz carrier only
FengYun 1C 180,006 MHz
FengYun 1D 180,007 MHz
destroyed Jan 2007
13
ORBCOMM - short messages relaying system - M2M
applications (machine-to-machine) - channels on
137-138 MHz - constellation of cca. 36
satellites - strong signal, 20W SD-PSK user
signal at 4800 bit/s - 5W Gateway Transmitter,
O-QPSK at 57,6 kbps, 137,56 MHz - non-modulated
beacon on 400,1 MHz - in the past interfered with
NOAA satellites transmissions - telemetry can be
decoded
above Orbcomm, 400.1 MHz right
Orbcomm, 137 MHz
14
NNSS (Navy Navigational Satellite System) -
first trials in 1964 - initially for military use
only, later available for civilian use also -
satellites known also as TRANSIT or OSCAR (not
to be confused with HAM OSCAR sats) - last
launches in spring and summer 1988 - discontinued
for navigation at the end of 1996 - now used as
NIMS Navy Ionospheric Monitoring System -
characteristic multi-tone audio NNS O-23 O-25
149,988 MHz and 399,968 MHz NNS O-31 O-32
149,978 MHz and 399,942 MHz
15
- example of FM demodulation spectrogram -
components at 2200-2400 and 4500-4700 kHz (and
higher) - melodic multi-tone audio, little known
about data format and encoding - power 0,75 1 W
16
Special place in history Transit 5B-5 (NNS
O-2) - launched 15 december 1964 - useless
due to malfunctioning two weeks after launch, but
continued to transmit - probably the oldest
satellite still transmitting - 136,650 MHz -
signal sounds similar to other NNS sats (but at
twice the speed and components at 5,4 kHz
and just under 10 kHz) - or simple carrier
only - or a typical unstable signal - this
probably depends on whether satellite has enough
power (sunlit, etc...)
17
Transit 5b5 NNS O-2 spectrogram examples SSB
spectrogram
above unstable signal
right 5.4 kHz signal
18
Transit 5b5 NNS O-2 spectrogram examples
FM spectrogram
5.4 kHz
10 kHz
19
Russian LEO navigational satellites
COSMOS-PARUS - two sub-systems, Nadezhda (civil,
no longer active) and Parus (military) - Parus -
6 orbital planes 30 deg. apart, usualy one active
satellite per orbital plane - easy to detect,
strong signals (1W) - RTTY, 50bit/s - 3 kHz and
5 kHz (plus 7kHz time reference signal) - signal
contains standard Moscow time information and
satellite positions - frequencies 149.910,
149.940, 149.970 and 150.030 MHz) - new
satellites, e.g. Cosmos 2414 january 2005 Cosmos
2398 (149,910 MHz and 399,760 MHz) Cosmos 2378
(149,940 MHz and 399,840 MHz) Cosmos 2407
(149,970 MHz and 399,920 MHz) Cosmos 2414
(149,970 MHz and 399,920 MHz)
20
COSMOS PARUS, FM signal
- 3 and 5 kHz RTTY components (50 bit/s) - 7 kHz
attenuated by receiver filters and barely visible
21
COSMOS PARUS, SSB signal examples
left 3 and 5 kHz components
below 7 kHz time reference
right UHF signal
22
SATELLITE BEACONS AT 150,0125 MHz
- quite a few satellites are carrying a beacon on
this frequency, some more to be launched in the
near future (NPSAT, STPSAT1, C/NOFS,...). -
usually also a beacon at 400,032 MHz (and some in
L-band also) - Main use of the beacons are
ionospheric measurements (similar to the
ex-navigation NIMS sats) by measuring the delay
in VHF and UHF signal arrival various parameters
of the ionosphere can be estimated (e.g. TEC
total electron content, ionospheric tomography,
etc.)
23
SATELLITE BEACONS AT 150,0125 MHz
- GEOSAT (GEOdetic SATellite), U.S. Navy sat,
main equipment is radar altimeter for precision
measurement of sea waves height) - GFO - GEOSAT
FOLLOW-ON, similar to GEOSAT in purpose -
RADCAL, used as a target for C-band radars
calibration, GPS attitude
demonstrator, UHF store-and-forward - SIX
FORMOSAT 3 series satellites (3A,3B,3C,3D,3E,3F)
, joint USA-Taiwan project, known also as
COSMIC (Constellation Observing System for
Meteorology, Ionosphere and Climate), same
spacecraft type as the Orbcomm ones.
24
SATELLITE BEACONS AT 150,0125 MHz
GEOSAT, 150.0125 MHz
RADCAL, 150.0125 MHz
GFO, 150.0125 MHz
25
SATELLITE BEACONS AT 150,0125 MHz
FORMOSAT 3D, 3E, 3B - formation flight
At the beginning all three sats (flying
relatively close together) have the same speed
relative to the receiver. As the satellites are
approaching us, their speed difference relative
to the receiver increases (due to different
spatial position of each satellite) and the
traces spread. While flying away, the opposite
happens and at the end the traces merge into a
single one.
26
OTHER SATELLITES IN THE 136-138 MHz BAND
- some older survived sats Tiros-N (137.500
MHz and 137.770 MHz) Tiros-10 (136.233 MHz)
Nimbus-4 (136.500 MHz) Solrad 7B (136.800
MHz) Isis-1 (136.410 MHz) EGRS-13 /
Secor-13 (136.800 MHz) Timation-2 (137.380
MHz) ERS-15 (136.400 MHz) Poppy 6 (137.410
MHz) and Poppy 7 (137.080 MHz) Shinsei
(136.695 MHz) Eutelsat 1-F4 (137.142 MHz) -
some newer also Mimosa (137.140MHz), Compass-2
(137.350MHz), Hamsat VO-52 (137.150 MHz,
137.200 MHz, 137.225 MHz) - usually some kind of
telemetry, unstable signal or non-modulated
carrier - there are some other reported (ERS-20,
etc.) but I was not able to hear them.
Solrad-7B
Tiros-10
Nimbus-4
Tiros-N
Poppy
Shinsei
Isis-1
EGRS-13
Mimosa
Compass-2
27
OTHER SATELLITES IN THE 136-138 MHz BAND Old
weather satellites (Tiros 10, Tiros N)
Tiros-N, 137,770 MHz
Tiros-N, 137,500 MHz
Tiros-10, 136,233 MHz 1,3 kHz AM
28
OTHER SATELLITES IN THE 136-138 MHz BAND Old
weather satellites (Nimbus-4, 136.500 MHz)
left Nimbus-4, 4000bps PCM/PM VIP (Versatile
Information Processor) data.
right Nimbus-4, unstable signal, sometimes
fluctuating at random, sometimes a stable
carrier...
29
OTHER SATELLITES IN THE 136-138 MHz BAND
a few other examples
ERS-15
SOLRAD 7B
SOLRAD 7B, unstable attitude
30
OTHER SATELLITES IN THE 136-138 MHz BAND
above MIMOSA (and VO-52)
above Compass-2
left HamSat (VO-52)
31
PASSIVE SATELLITE REFLECTIONS NAVSPASUR RADAR
- U.S. Navy satellite - tracking radar -
continous non-modulated TX, separate TX-RX sites
- 3 TX sites Gila River 216.970MHz
Jordan Lake 216.990 MHz
Lake Kickapoo 216.980 MHz (the
strongest) - 3,2 km linear array 2556 dipoles,
each has 300W amp - 767kW input power and 40dB
antenna gain -gt 6,3 GW ERP - fence-shaped
antenna pattern - moonbounce reflection with RX
dipole in USA - moon and sat reflections can be
observed in Europe GRAVES, 143.050 MHz - active
since 2006 - similar in purpose to NAVSPASUR -
but less powerful (heights up to 1000 km) - ERP
several megawatts - located in France, TX
(central France) - RX (south France) cca 300 km
32
THANK YOU!
33
SOME USEFUL LINKS
http//fpp.hamradio.si/s53ra/xhamradio/hamsatvar
1.html http//www.uhf-satcom.comhttp//mdkenny.
customer.netspace.net.au/emitters.htmlhttp//www.
zarya.info http//www.svengrahn.pp.sehttp//space
.skyrocket.dehttp//home.arcor.de/satellitenwelt
http//www.itr-datanet.com/pe1itr/ http//www.hea
vens-above.comhttp//nssdc.gsfc.nasa.gov/nmc/sc-q
uery.htmlhttp//centaur.sstl.co.uk/sshphttp//ww
w.hearsat.org Satscape www.satscape.co.ukDL4YH
F Spectrum Lab http//people.freenet.de/dl4yhf/sp
ectra1.html