Radio Frequency Interference Analysis of Spectra
from the Big Blade Antenna at the LWDA Site
Robert Duffin (GMU/NRL) and Paul S. Ray (NRL)
March 23, 2007
Introduction
The LWA analog receiver will be required to amplify and digitize RF signals over the full
bandwidth of at least 20–80 MHz. This frequency range is populated with a number of strong
sources of radio frequency interference (RFI), including several TV stations, HF broadcast
transmissions, ham radio, and is adjacent to the FM band. Although filtering can be used to
attenuate signals outside the band, the receiver must be designed with sufficient linearity and
dynamic range to observe cosmic sources in the unoccupied regions between the, typically
narrowband, RFI signals. A receiver of insufficient linearity will generate inter-modulation
products at frequencies in the observing bands that will make it difficult or impossible to
accomplish the science objectives. On the other hand, over-designing the receiver is undesirable
because any excess cost or power usage will be multiplied by the 26,000 channels in the full
design and may make the project unfeasible.
Since the sky background is low level and broadband, the linearity requirements primarily
depend on the RFI signals presented to the receiver. Consequently, a detailed study of the RFI
environment at candidate LWA sites is essential. Often RFI surveys are done using antennas
optimized for RFI detection such as discone antennas. However, such data are of limited
usefulness for setting the receiver requirements because what is relevant is what signals are
passed to the receiver when it is connected to the actual LWA antenna. Thus, we have chosen to
do an RFI survey using the Big Blade antenna that was specified as the strawman LWA antenna
design in LWA Memo #35.
We investigated the statistics of the RFI across the spectrum by looking at the minimum, median,
and maximum at each frequency over several different time intervals. We also tabulate the
maximum power in each of the known TV and FM channels in the band. Finally, we tabulate the
frequency and power spectral density (PSD) of all other RFI found in the spectra over several
different time intervals.
The measurements presented here were made at the LWDA site about 60 miles west of Socorro,
New Mexico near the center of the VLA. Clearly, this data collection and analysis needs to be
repeated at many (if not all) candidate LWA station sites.
Data Collection and Analysis
The Specmaster system (see LWA Memo #74) was configured to collect a spectrum from the
Big Blade antenna about once per second, with summed data dumped every two sweeps. We set
the averaging mode to power averaging (RMS) and the detector type to sample mode. Each
measured spectrum covers 2000 frequency bins over the range 13.0 to 115.0 MHz with a
resolution bandwidth (RBW) of 51 kHz per frequency bin. This densely samples the spectrum
over the full frequency range, i.e. even a narrowband signal can’t hide between two frequency
bins, as is possible when the RBW is less than the step between frequency bins. Data have been
collected in this basic configuration since October 2006. For the current analysis, we are using
the data from the Big Blade dipole oriented North-South. We chose to analyze a set of data from
2006-11-28 17:00 to 2006-11-29 1700 MT due to a lack of obvious solar bursts during that time
period.
Figure 1. Diagram of experimental set-up for big blade measurements. Balun gain was +24 dB,
amplifier gain +17 dB and the cable loss was calculated from site measurements.
Corrections Applied to Data
In all of our analysis, we report power spectral densities, in dB(mW/RBW), converted back to
the levels at the balun input. This requires correcting the measured power from the spectrum
analyzer to account for the active gain in the system, as well as the loss in the RF transmission
cable.
The active gain in the system is Gbalun = +24 dB from the Hicks/TeleTech balun, and Gamp = +17
dB from the Mini-Circuits ZHL-1A amplifier, both assumed to be independent of frequency. The
cable loss correction was derived from earlier measurements made by S. Ellingson of the same
cables, as documented in LWA Memo #42 (see Figure 7 in that memo). We used a simple linear
fit of the data (in dB) vs. frequency as our cable loss model, which is
Lcable (dB) = 0.0395 fMHz +1.6274 , where fMHz is the frequency in MHz
!
Sky Temperature Model
We define an objective criterion that RFI will be included in our lists if it exceeds the power
expected from the sky background in a 51 kHz bin by 10 dB. 10 dB was adopted as a fiducial
value, as levels below this are unlikely to cause linearity problems. We compute the expected
sky noise beginning with the model of Cane (1979, MNRAS, 189, 465), using for intensity
I! = I g! #0.52
1 # e #" (! )
+ I eg! #0.80 e #" (! )
" (! )
with units of W m-2 Hz-1 sr-1, where I g = 2.48 " 10 !20 (Galaxy contribution), # (" ) = 5.0" !2.1 ,
I eg = 1.06 " 10 !20 (extragalactic noise) and! (for this situation) is the frequency in MHz. (see
Eqn. 18 of LWA Memo #22 by S. Ellingson). The sky temperature model is converted from
units of T [K] to units of PSD[dB (mw/RBW), RBW=51 kHz] using
P = B kB T
where B is the bandwidth, kB is Boltzmann’s constant and T is temperature in Kelvin.
To compute the expected power from the sky, we corrected for the impedance mismatch
efficiency (IME) and predicted ground loss, as described in LWA Memo #40, eqns. 1–5. The
IME was computed using a NEC-2 model of the big blade, and the ground loss was modeled
using the data from Memo #40, Fig 11, which is for a somewhat different antenna, but is close
enough for the purposes of this work.
We then added 250K, independent of frequency, to the model to account for the excess noise
contributed by the balun. Note that the sky temperature model predicts the minimum power from
the sky since it is based on the sky spectrum at the galactic pole. The measured sky power can
exceed this by a couple of dB at the maximum of the diurnal variation, which will cause a slight
change in our RFI detection threshold as a function of local sidereal time.
Analysis
To show the overall character of the RFI, we plot the maximum, minimum and median power
spectral density (PSD) [dB (mw/RBW), RBW=51.0 kHz] over four different 5-minute intervals
separated by 6 hours (Figures 2–5). In Figure 6, we show the same statistics computed over a 24hour interval. Looking at the minima (blue line) it is clear that nearly all frequency bins are
unoccupied by RFI at least some of the time. The clear exception, are the TV stations and FM
stations. In addition, the TV and FM transmissions are of known frequency and bandwidth. As a
result, we have chosen to separately analyze the TV and FM signals from the rest of the
intermittent RFI.
The TV and FM signals are characterized in Tables 2 and 3, where the difference between the
tables is simply an integration time of 5 minutes for Table 2 and 24 hours for Table 3. For the
NTSC TV stations, we tabulate the maximum power in 306 kHz (6 RBW bins) bandwidth at the
audio and video carriers for each channel. We also tabulate the maximum total power in the full
6 MHz (118 RBW bins) ATSC frequency channel. For each of the 100 allocated FM stations, we
tabulate the maximum power in a 204 kHz (4 RBW bins) bandwidth over the integration time.
We then excluded the frequencies of the NTSC TV carriers and FM radio bands from the
analysis of the sporadic RFI environment. Tables 4–7 display the RFI signals above our
threshold over four 5-minute intervals spaced by 6 hours.
New 40 MHz RFI Signal Detected
With different data than used in the above analysis, a 40 MHz signal has been observed with the
EW polarization of the Big-Blade-1 antenna over a period of three months (Figure 7). This 40
MHz RFI has a central frequency at ~39.9 MHz, with a ~1.0 MHz bandwidth. This RFI has
been observed at varying strengths since as early as October 2006. The strength of this RFI
increased greatly after a 6 hour data gap on December 6, 2006. The 40 MHz signal was much
lower in strength by January 28th, but has increased in strength up to February 24th, with the
strength then being roughly constant up to the present (2007-03-06).
Analysis on the Fork (online 2007-01-17) and the new Big Blade antenna (Big-Blade-2, online
2007-02-16) may help with the determination of the source of the 40 MHz RFI. The 40 MHz
signal was not observed with the NS polarization of the Fork or of Big-Blade-1, but is now being
observed with the NS polarization of the Big-Blade-2. With the Big-Blade-1 balun apparently
turned off during the change-over from Big-Blade-1 to Big-Blade-2 on 2007-02-16, the 40 RFI
MHz signal was observed in the data gap (~19:45 to 20:32UT) for Big Blade-1 and the data gap
(~20:32 to 20:39UT) of Big-Blade-2, which strongly suggest that the RFI is internally generated.
Occupancy Rate Plots
Looking at occupancy rates for each frequency bin can help identify the more frequent RFI. As
an example, we made log plots of occupancy rates over the second week of November 2006
when higher intensity solar bursts were absent. For clarity we divided the 13 to 115 MHz range
into three sections 13 to 51 MHz, 49 to 89 MHz (covering all TV station bandwidths) and 87 to
115 MHz (covering all FM station bandwidths). The Figures 8-10 show some rates below 0.1%
from roughly 30 to 55 MHz, between the TV station signals and at frequencies above 108.5 MHz
(higher than FM station bandwidths).
Over the one week period, TV channel 2 and 5 showed rates of 100% occupancy; TV channel 3
showed rates of 1-10% for Video and Audio signal; TV channel 4 showed 100% for Video and
1-10% for Audio; TV channel 6 showed 1-10% for Video and 100% for the Audio signal.
Most of the FM stations observed, showed 100% occupancy rate with others mostly above 10%.
These observations are some of the reasons why continued RFI monitoring is important to the
project. For reference, FCC frequency allocations 12.23 to 117.975 MHz are shown in Figure 11.
Figure 2. 5-min (period 1) spectra after gain & cable loss corrections.
Figure 3. 5-min (period 2) spectra after gain & cable loss corrections.
Figure 4. 5-min (period 3) spectra after gain & cable loss corrections.
Figure 5. 5-min (period 4) spectra after gain & cable loss corrections.
Figure 6. 24-hours of Spectra after gain and cable loss corrections.
Figure 7. One-hour spectra over 3 months showing 40 MHz RFI strength.
Figure 8. Occupancy plot (13-51 Mhz) showing percent of time PSD> Sky Temp Model+10 dB.
Figure 9. Occupancy plot (49-89 Mhz) showing percent of time PSD> Sky Temp Model+10 dB.
Figure 10. Occupancy plot (87-115 Mhz) showing percent of time PSD> Sky Temp Model+10 dB.
Figure 11. Frequency allocations from 12.23 to 117.975 MHz
(http://www.ntia.doc.gov/osmhome/allochrt.pdf)
Table 2. TV/FM ref. for instantaneous PSD[dB mw/RBW] at Balun Input
of Specmaster spectra. Max of sweeps: 2006-11-29 07:00-07:05 MT.
TV/FM CHNL
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
KASA
KASA
KASA
KENW
KENW
KENW
KOB
KOB
KOB
KNME
KNME
KNME
KOCT
KOCT
KOCT
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
2
2
2
3
3
3
4
4
4
5
5
5
6
6
6
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
KNMA
KLYT
KPKJ
990428MC
KNMI
KANW/KQAI
KELP
KVLK
KTDB
KUNM
KRDR/KRLU
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
KZRR
32
33
REF_FREQ
SIGNAL_TYPE
PSD_SUM PSD_UNITS_in_[RBW]
55.26
59.76
57.01
61.26
65.76
63.01
67.26
71.76
69.01
77.26
81.76
79.01
83.24
87.74
84.99
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
NTSC Video, -83.50 dB(mw/RBW) in
NTSC Audio, -92.56 dB(mw/RBW) in
ATSC,
-82.66 dB(mw/RBW) in
NTSC Video, -81.46 dB(mw/RBW) in
NTSC Audio, -91.22 dB(mw/RBW) in
ATSC,
-80.87 dB(mw/RBW) in
NTSC Video, -89.14 dB(mw/RBW) in
NTSC Audio, -92.75 dB(mw/RBW) in
ATSC,
-87.47 dB(mw/RBW) in
NTSC Video, -92.68 dB(mw/RBW) in
NTSC Audio, -92.92 dB(mw/RBW) in
ATSC,
-89.38 dB(mw/RBW) in
NTSC Video, -102.66 dB(mw/RBW) in
NTSC Audio, -103.98 dB(mw/RBW) in
ATSC,
-96.72 dB(mw/RBW) in
88.1
88.3
88.5
88.7
88.9
89.1
89.3
89.5
89.7
89.9
90.1
90.3
90.5
90.7
90.9
91.1
91.3
91.5
91.7
91.9
92.1
92.3
92.5
92.7
92.9
93.1
93.3
93.5
93.7
93.9
94.1
94.3
94.5
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
-96.81
-96.61
-99.12
-95.57
-95.82
-80.36
-102.91
-96.04
-91.68
-81.61
-103.32
-98.17
-98.18
-95.63
-103.87
-101.96
-100.92
-82.89
-103.49
-104.36
-103.85
-86.35
-98.10
-100.47
-92.23
-93.25
-81.61
-105.10
-100.06
-93.92
-85.15
-101.35
-95.47
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
306 kHz
306 kHz
6.018 MHz
306 kHz
306 kHz
6.018 MHz
306 kHz
306 kHz
6.018 MHz
306 kHz
306 kHz
6.018 MHz
306 kHz
306 kHz
6.018 MHz
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
Table 2 continued...
TV/FM CHNL
REF_FREQ
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
94.7
94.9
95.1
95.3
95.5
95.7
95.9
96.1
96.3
96.5
96.7
96.9
97.1
97.3
97.5
97.7
97.9
98.1
98.3
98.5
98.7
98.9
99.1
99.3
99.5
99.7
99.9
100.1
100.3
100.5
100.7
100.9
101.1
101.3
101.5
101.7
101.9
102.1
102.3
102.5
102.7
102.9
103.1
103.3
103.5
103.7
103.9
104.1
104.3
34
35
36
37
38
39
Magdelena
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
SIGNAL_TYPE
PSD_SUM PSD_UNITS_in_[RBW]
-103.31
-98.07
-97.43
-95.45
-94.76
-94.15
-99.82
-96.05
-84.75
-97.48
-108.01
-103.30
-95.57
-86.61
-98.10
-97.24
-103.46
-103.51
-100.49
-84.27
-98.14
-103.75
-100.51
-102.49
-86.54
-102.23
-100.37
-104.93
-84.78
-101.44
-105.34
-103.97
-98.27
-96.96
-95.71
-99.69
-104.56
-92.77
-93.79
-101.30
-104.02
-99.04
-100.23
-82.51
-106.67
-101.25
-103.18
-85.62
-104.48
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
Table 2 continued...
TV/FM CHNL
REF_FREQ
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
104.5
104.7
104.9
105.1
105.3
105.5
105.7
105.9
106.1
106.3
106.5
106.7
106.9
107.1
107.3
107.5
107.7
107.9
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
SIGNAL_TYPE
PSD_SUM PSD_UNITS_in_[RBW]
-95.95
-87.53
-101.62
-86.55
-94.20
-90.55
-102.80
-87.82
-105.99
-95.82
-104.92
-93.28
-96.87
-88.32
-99.03
-97.27
-102.32
-83.70
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
Table 3. TV/FM ref. for instantaneous PSD[dB mw/RBW] at Balun Input of
Specmaster spectra. Max of sweeps: 2006-11-28 17:00 MT to 2006-11-29 17:00 MT
TV/FM CHNL
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
TV
KASA
KASA
KASA
KENW
KENW
KENW
KOB
KOB
KOB
KNME
KNME
KNME
KOCT
KOCT
KOCT
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
2
2
2
3
3
3
4
4
4
5
5
5
6
6
6
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
KNMA
KLYT
KPKJ
990428MC
KNMI
KANW/KQAI
KELP
KVLK
KTDB
KUNM
KRDR/KRLU
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
KZRR
32
REF_FREQ
SIGNAL_TYPE
55.26
59.76
57.01
61.26
65.76
63.01
67.26
71.76
69.01
77.26
81.76
79.01
83.24
87.74
84.99
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
NTSC Video,
NTSC Audio,
ATSC,
NTSC Video,
NTSC Audio,
ATSC,
NTSC Video,
NTSC Audio,
ATSC,
NTSC Video,
NTSC Audio,
ATSC,
NTSC Video,
NTSC Audio,
ATSC,
88.1
88.3
88.5
88.7
88.9
89.1
89.3
89.5
89.7
89.9
90.1
90.3
90.5
90.7
90.9
91.1
91.3
91.5
91.7
91.9
92.1
92.3
92.5
92.7
92.9
93.1
93.3
93.5
93.7
93.9
94.1
94.3
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
PSD_SUM PSD_UNITS_in_[RBW]
-81.84
-89.27
-81.16
-78.81
-91.22
-78.51
-83.42
-90.57
-82.48
-88.98
-90.63
-87.01
-89.51
-94.58
-87.94
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
306 kHz
306 kHz
6.018 MHz
306 kHz
306 kHz
6.018 MHz
306 kHz
306 kHz
6.018 MHz
306 kHz
306 kHz
6.018 MHz
306 kHz
306 kHz
6.018 MHz
-89.39
-93.36
-88.91
-89.63
-79.65
-78.97
-91.06
-91.14
-87.61
-80.57
-85.75
-91.18
-85.59
-86.38
-85.33
-84.00
-93.26
-80.45
-89.46
-94.57
-86.23
-84.01
-88.42
-90.52
-91.22
-89.33
-79.34
-96.91
-88.90
-86.37
-84.28
-92.71
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
Table 3 continued...
TV/FM CHNL
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
33
34
35
36
37
38
39
Magdelena
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
REF_FREQ
94.5
94.7
94.9
95.1
95.3
95.5
95.7
95.9
96.1
96.3
96.5
96.7
96.9
97.1
97.3
97.5
97.7
97.9
98.1
98.3
98.5
98.7
98.9
99.1
99.3
99.5
99.7
99.9
100.1
100.3
100.5
100.7
100.9
101.1
101.3
101.5
101.7
101.9
102.1
102.3
102.5
102.7
102.9
103.1
103.3
103.5
103.7
103.9
104.1
104.3
104.5
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
SIGNAL_TYPE
PSD_SUM PSD_UNITS_in_[RBW]
-85.27
-89.36
-88.32
-90.19
-86.84
-87.81
-83.46
-95.78
-86.52
-81.91
-87.28
-93.18
-87.72
-90.71
-84.80
-89.28
-88.98
-89.67
-89.25
-87.23
-83.00
-90.93
-90.07
-89.78
-87.13
-83.26
-91.79
-87.45
-92.81
-80.82
-91.36
-84.15
-99.12
-89.40
-92.42
-82.95
-92.43
-90.62
-89.64
-91.92
-93.35
-92.43
-89.05
-91.71
-80.27
-91.64
-92.90
-91.74
-82.68
-95.26
-92.52
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
Table 3 continued...
TV/FM CHNL
REF_FREQ
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
FM
104.7
104.9
105.1
105.3
105.5
105.7
105.9
106.1
106.3
106.5
106.7
106.9
107.1
107.3
107.5
107.7
107.9
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
MHz
SIGNAL_TYPE
PSD_SUM PSD_UNITS_in_[RBW]
-82.30
-96.12
-83.58
-89.00
-88.06
-85.86
-85.08
-85.35
-88.18
-93.60
-93.28
-91.84
-87.11
-89.48
-93.15
-90.14
-81.41
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
dB(mw/RBW)
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
in
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
204
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
kHz
Table 4. Unknown RFI of Specmaster spectra (2006-11-28 19:00-19:05 MT) >
(SkyTMod+10), PSD[dB mw/RBW] at Bal Input (max per frequency channel).
SM MAX FREQ[MHz]
13.05
13.10
13.20
13.26
13.31
13.36
13.46
13.61
13.66
13.71
13.77
14.99
15.14
15.19
15.25
15.30
15.35
15.40
15.45
15.50
15.65
15.70
15.76
17.08
17.13
17.64
17.69
49.89
75.91
75.97
108.01
108.06
108.11
SM PEAK[PSD] SkyTmod+10[PSD]
-115.00
-111.56
-100.08
-85.89
-88.53
-109.78
-115.32
-107.54
-102.01
-108.92
-105.80
-112.72
-104.36
-95.80
-99.38
-111.80
-100.84
-78.60
-75.42
-88.70
-105.12
-93.37
-98.26
-107.09
-111.51
-106.30
-106.18
-107.17
-110.60
-111.44
-95.83
-106.03
-110.12
-115.49
-115.47
-115.43
-115.41
-115.39
-115.37
-115.33
-115.26
-115.24
-115.22
-115.19
-114.61
-114.53
-114.50
-114.47
-114.45
-114.42
-114.39
-114.36
-114.34
-114.25
-114.22
-114.20
-113.42
-113.39
-113.08
-113.05
-109.11
-112.34
-112.34
-114.29
-114.29
-114.30
Table 5. Unknown RFI of Specmaster spectra (2006-11-29 01:00-01:05 MT) >
(SkyTMod+10), PSD[dB mw/RBW] at Bal Input (max per frequency channel).
SM MAX FREQ[MHz]
13.15
13.20
13.36
13.41
13.46
13.56
13.61
13.66
15.14
15.19
15.35
15.40
15.45
17.64
43.21
43.62
75.91
75.97
108.01
108.06
108.11
SM PEAK[PSD] SkyTmod+10[PSD]
-113.36
-109.61
-115.14
-108.28
-113.08
-109.66
-97.57
-101.95
-109.74
-104.84
-110.91
-105.40
-113.27
-111.58
-104.38
-107.42
-111.25
-112.29
-97.64
-105.65
-109.41
-115.45
-115.43
-115.37
-115.35
-115.33
-115.28
-115.26
-115.24
-114.53
-114.50
-114.42
-114.39
-114.36
-113.08
-107.71
-107.81
-112.34
-112.34
-114.29
-114.29
-114.30
Table 6. Unknown RFI of Specmaster spectra (2006-11-29 07:00-07:05 MT) >
(SkyTMod+10), PSD[dB mw/RBW] at Bal Input (max per frequency channel).
SM MAX FREQ[MHz]
13.00
13.05
13.10
13.15
13.20
13.26
13.31
13.36
13.41
13.46
13.51
13.56
13.61
13.66
13.71
13.77
13.82
13.87
13.92
13.97
14.02
14.07
14.12
14.17
14.22
14.28
14.33
14.38
14.43
14.48
14.53
14.58
14.63
14.68
14.73
14.79
14.84
14.89
14.94
14.99
15.04
15.09
15.14
15.19
15.25
15.30
15.35
15.40
15.45
15.50
SM PEAK[PSD] SkyTmod+10[PSD]
-102.74
-102.66
-94.04
-100.29
-106.98
-106.29
-97.35
-103.30
-109.96
-107.83
-95.71
-85.97
-80.35
-70.82
-74.62
-77.57
-84.42
-93.51
-110.45
-107.53
-104.03
-97.70
-106.16
-100.65
-98.78
-99.50
-105.80
-107.56
-109.81
-104.61
-109.56
-105.25
-104.22
-104.42
-109.26
-109.69
-113.15
-112.18
-111.59
-109.37
-100.88
-80.13
-78.02
-74.60
-70.27
-77.04
-63.37
-66.22
-88.03
-104.53
-115.51
-115.49
-115.47
-115.45
-115.43
-115.41
-115.39
-115.37
-115.35
-115.33
-115.30
-115.28
-115.26
-115.24
-115.22
-115.19
-115.17
-115.15
-115.12
-115.10
-115.08
-115.05
-115.03
-115.01
-114.98
-114.96
-114.94
-114.91
-114.89
-114.86
-114.84
-114.81
-114.79
-114.76
-114.74
-114.71
-114.69
-114.66
-114.63
-114.61
-114.58
-114.55
-114.53
-114.50
-114.47
-114.45
-114.42
-114.39
-114.36
-114.34
Table 6 continued...
SM MAX FREQ[MHz]
15.55
15.60
15.65
15.70
15.76
15.81
15.86
15.91
15.96
16.01
16.16
16.21
16.42
16.47
16.52
16.57
16.62
16.67
16.72
16.78
16.83
16.88
16.93
16.98
17.08
17.13
17.18
17.24
17.29
17.34
17.39
17.44
17.49
17.54
17.59
17.64
17.69
17.75
17.80
17.85
17.90
17.95
18.00
18.05
18.10
18.15
18.20
18.66
18.71
18.77
SM PEAK[PSD] SkyTmod+10[PSD]
-95.75
-99.11
-91.48
-74.14
-71.42
-80.21
-84.70
-94.93
-101.14
-113.55
-113.23
-112.55
-111.71
-98.13
-100.12
-98.97
-92.37
-94.79
-110.03
-105.41
-103.93
-110.08
-110.66
-109.10
-101.96
-91.36
-96.13
-96.61
-98.33
-103.69
-105.52
-104.45
-102.11
-88.25
-81.08
-89.31
-80.46
-69.50
-74.79
-74.00
-83.23
-109.65
-102.12
-89.55
-93.32
-104.69
-110.92
-105.06
-98.24
-105.95
-114.31
-114.28
-114.25
-114.22
-114.20
-114.17
-114.14
-114.11
-114.08
-114.05
-113.97
-113.94
-113.82
-113.79
-113.76
-113.73
-113.70
-113.67
-113.64
-113.61
-113.58
-113.54
-113.51
-113.48
-113.42
-113.39
-113.36
-113.33
-113.30
-113.27
-113.23
-113.20
-113.17
-113.14
-113.11
-113.08
-113.05
-113.01
-112.98
-112.95
-112.92
-112.89
-112.86
-112.82
-112.79
-112.76
-112.73
-112.44
-112.41
-112.38
Table 6 continued...
SM MAX FREQ[MHz]
18.87
18.92
18.97
19.02
19.07
19.12
19.28
19.33
19.38
19.43
19.48
19.53
19.58
19.63
19.74
19.84
19.89
19.94
19.99
20.04
20.09
20.14
20.19
20.25
21.01
21.06
21.11
21.32
21.37
21.47
21.52
21.57
21.62
21.67
21.93
21.98
22.34
22.39
22.44
22.49
23.21
26.98
27.08
27.13
27.19
27.29
33.00
75.91
108.01
108.06
108.11
SM PEAK[PSD] SkyTmod+10[PSD]
-103.63
-94.55
-100.90
-107.60
-101.53
-101.96
-101.59
-95.44
-102.58
-103.19
-103.85
-108.34
-100.68
-107.03
-110.31
-104.23
-106.65
-108.73
-111.09
-104.64
-100.92
-108.81
-108.94
-108.89
-106.04
-98.42
-106.15
-105.46
-109.85
-105.46
-104.20
-88.47
-84.27
-94.44
-107.19
-108.60
-108.11
-102.09
-107.31
-105.77
-108.96
-105.09
-103.51
-106.94
-106.84
-106.86
-106.09
-112.10
-96.07
-105.15
-110.64
-112.31
-112.28
-112.25
-112.22
-112.18
-112.15
-112.06
-112.02
-111.99
-111.96
-111.93
-111.90
-111.86
-111.83
-111.77
-111.71
-111.67
-111.64
-111.61
-111.58
-111.55
-111.52
-111.48
-111.45
-110.98
-110.95
-110.92
-110.80
-110.77
-110.70
-110.67
-110.64
-110.61
-110.58
-110.43
-110.40
-110.18
-110.15
-110.12
-110.09
-109.66
-107.63
-107.59
-107.57
-107.54
-107.50
-106.16
-112.34
-114.29
-114.29
-114.30
Table 7. Unknown RFI of Specmaster spectra (2006-11-29 13:00-13:05 MT) >
(SkyTMod+10), PSD[dB mw/RBW] at Bal Input (max per frequency channel)
SM MAX FREQ[MHz]
13.00
13.05
13.10
13.15
13.20
13.26
13.31
13.36
13.41
13.46
13.51
13.56
13.61
13.66
13.71
13.77
13.82
13.87
13.92
13.97
14.02
14.07
14.12
14.17
14.22
14.28
14.33
14.38
14.43
14.48
14.53
14.58
14.63
14.68
14.73
14.79
14.84
14.89
14.94
14.99
15.04
15.09
15.14
15.19
15.25
15.30
15.35
15.40
15.45
SM PEAK[PSD] SkyTmod+10[PSD]
-84.87
-77.01
-85.41
-86.81
-94.44
-101.19
-100.50
-101.86
-101.72
-101.18
-94.40
-85.59
-92.64
-93.37
-89.13
-75.33
-58.96
-59.90
-79.35
-100.06
-90.90
-89.22
-87.45
-85.91
-83.63
-73.21
-78.34
-103.63
-113.23
-100.69
-95.98
-106.87
-94.33
-92.72
-106.84
-103.13
-110.09
-113.06
-108.98
-99.96
-93.81
-74.14
-72.25
-79.63
-72.31
-81.11
-92.67
-84.86
-81.88
-115.51
-115.49
-115.47
-115.45
-115.43
-115.41
-115.39
-115.37
-115.35
-115.33
-115.30
-115.28
-115.26
-115.24
-115.22
-115.19
-115.17
-115.15
-115.12
-115.10
-115.08
-115.05
-115.03
-115.01
-114.98
-114.96
-114.94
-114.91
-114.89
-114.86
-114.84
-114.81
-114.79
-114.76
-114.74
-114.71
-114.69
-114.66
-114.63
-114.61
-114.58
-114.55
-114.53
-114.50
-114.47
-114.45
-114.42
-114.39
-114.36
Table 7 continued...
SM MAX FREQ[MHz]
15.50
15.55
15.60
15.65
15.70
15.76
15.81
15.86
15.91
15.96
16.01
16.06
16.11
16.16
16.21
16.27
16.32
16.37
16.42
16.47
16.52
16.57
16.62
16.67
16.72
16.78
16.83
16.88
16.93
16.98
17.03
17.08
17.13
17.18
17.24
17.29
17.34
17.39
17.44
17.49
17.54
17.59
17.64
17.69
17.75
17.80
17.85
17.90
17.95
18.00
SM PEAK[PSD] SkyTmod+10[PSD]
-90.56
-94.67
-88.00
-78.44
-75.42
-72.89
-86.17
-92.21
-93.00
-88.83
-99.19
-101.62
-94.05
-101.34
-77.10
-71.54
-82.07
-112.27
-107.39
-108.21
-103.24
-94.04
-92.99
-106.06
-107.87
-86.33
-83.63
-97.53
-101.05
-101.18
-98.82
-87.97
-76.90
-82.49
-90.69
-94.66
-97.92
-103.12
-98.44
-75.22
-69.16
-66.75
-77.23
-82.96
-73.55
-71.82
-67.54
-76.73
-102.75
-110.64
-114.34
-114.31
-114.28
-114.25
-114.22
-114.20
-114.17
-114.14
-114.11
-114.08
-114.05
-114.02
-113.99
-113.97
-113.94
-113.91
-113.88
-113.85
-113.82
-113.79
-113.76
-113.73
-113.70
-113.67
-113.64
-113.61
-113.58
-113.54
-113.51
-113.48
-113.45
-113.42
-113.39
-113.36
-113.33
-113.30
-113.27
-113.23
-113.20
-113.17
-113.14
-113.11
-113.08
-113.05
-113.01
-112.98
-112.95
-112.92
-112.89
-112.86
Table 7 continued...
SM MAX FREQ[MHz]
18.05
18.10
18.15
18.20
18.26
18.31
18.36
18.41
18.46
18.51
18.56
18.61
18.66
18.71
18.77
18.82
18.87
18.92
18.97
19.02
19.07
19.12
19.17
19.23
19.28
19.33
19.43
19.48
19.53
19.63
19.68
19.74
19.79
19.84
19.89
19.99
20.04
20.09
20.19
20.25
20.30
20.35
20.40
20.45
20.50
20.55
20.60
20.65
20.81
20.86
SM PEAK[PSD] SkyTmod+10[PSD]
-104.17
-85.41
-80.09
-90.39
-105.82
-100.50
-106.52
-110.02
-109.02
-105.01
-105.05
-112.02
-103.26
-100.90
-104.99
-100.71
-85.93
-82.87
-96.11
-111.04
-110.98
-111.30
-108.08
-108.08
-101.74
-105.45
-106.38
-105.49
-106.46
-106.05
-105.46
-105.41
-110.85
-104.77
-103.47
-110.94
-104.07
-108.98
-108.84
-104.05
-107.76
-106.21
-95.24
-99.42
-105.05
-104.55
-103.04
-104.04
-108.65
-109.72
-112.82
-112.79
-112.76
-112.73
-112.70
-112.66
-112.63
-112.60
-112.57
-112.54
-112.50
-112.47
-112.44
-112.41
-112.38
-112.34
-112.31
-112.28
-112.25
-112.22
-112.18
-112.15
-112.12
-112.09
-112.06
-112.02
-111.96
-111.93
-111.90
-111.83
-111.80
-111.77
-111.74
-111.71
-111.67
-111.61
-111.58
-111.55
-111.48
-111.45
-111.42
-111.39
-111.36
-111.33
-111.30
-111.26
-111.23
-111.20
-111.11
-111.08
Table 7 continued...
SM MAX FREQ[MHz] SM PEAK[PSD] SkyTmod+10[PSD]
20.91
20.96
21.01
21.06
21.22
21.27
21.32
21.37
21.42
21.47
21.52
21.57
21.62
21.67
21.78
21.88
21.93
21.98
22.08
22.13
22.18
22.24
22.29
22.34
22.39
22.44
22.49
22.54
22.59
22.64
22.69
22.75
22.85
22.90
22.95
23.00
23.05
23.10
23.15
23.21
23.26
23.31
23.36
23.41
23.46
23.51
23.56
23.61
23.66
23.72
-101.43
-93.92
-101.98
-110.15
-110.10
-109.72
-110.52
-109.28
-108.31
-89.02
-82.24
-75.03
-70.62
-82.17
-108.16
-104.70
-109.16
-107.74
-103.72
-96.13
-99.08
-104.33
-106.54
-99.61
-95.52
-92.93
-96.86
-94.20
-94.60
-109.86
-109.38
-101.86
-99.66
-95.85
-94.23
-107.14
-94.88
-90.80
-89.57
-98.67
-108.52
-105.83
-88.51
-87.93
-93.96
-88.19
-91.93
-90.87
-87.48
-100.16
-111.05
-111.01
-110.98
-110.95
-110.86
-110.83
-110.80
-110.77
-110.73
-110.70
-110.67
-110.64
-110.61
-110.58
-110.52
-110.46
-110.43
-110.40
-110.33
-110.30
-110.27
-110.24
-110.21
-110.18
-110.15
-110.12
-110.09
-110.06
-110.03
-110.00
-109.97
-109.94
-109.87
-109.84
-109.81
-109.78
-109.75
-109.72
-109.69
-109.66
-109.63
-109.60
-109.57
-109.54
-109.51
-109.48
-109.45
-109.42
-109.39
-109.36
Table 7 continued...
SM MAX FREQ[MHz]
23.82
23.87
23.92
23.97
24.02
24.07
24.12
24.17
24.23
24.28
24.68
26.57
32.90
75.91
108.01
108.06
108.11
SM PEAK[PSD] SkyTmod+10[PSD]
-108.36
-100.52
-89.20
-94.35
-107.20
-99.33
-94.23
-91.08
-97.67
-102.02
-106.92
-105.82
-104.59
-111.47
-94.78
-104.43
-109.88
-109.30
-109.27
-109.24
-109.21
-109.18
-109.15
-109.12
-109.09
-109.06
-109.03
-108.80
-107.82
-106.16
-112.34
-114.29
-114.29
-114.30