U.S. Non-Federal-Government Allocations
EARTH EXPLORATION-SATELLITE (passive)
RADIO ASTRONOMY US74
SPACE RESEARCH (passive)
SpectrumWiki
Radio spectrum allocations
Look up a frequency or a range.
Examples: 88.5 MHz, 1350–1430 MHz, 2.4 GHz
1.4 GHz (1,400,000,000 Hz)
U.S. Federal Government Allocations
EARTH EXPLORATION-SATELLITE (passive)
RADIO ASTRONOMY US74
SPACE RESEARCH (passive)
ITU Region 1 Allocations
EARTH EXPLORATION-SATELLITE (passive)
RADIO ASTRONOMY
SPACE RESEARCH (passive)
ITU Region 2 Allocations
EARTH EXPLORATION-SATELLITE (passive)
RADIO ASTRONOMY
SPACE RESEARCH (passive)
ITU Region 3 Allocations
EARTH EXPLORATION-SATELLITE (passive)
RADIO ASTRONOMY
SPACE RESEARCH (passive)
Footnotes
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5.340 All emissions are prohibited in the following bands:
1 400-1 427 MHz,
2 690-2 700 MHz, except those provided for by No. 5.422,
10.68-10.7 GHz, except those provided for by No. 5.483,
15.35-15.4 GHz, except those provided for by No. 5.511,
23.6-24 GHz,
31.3-31.5 GHz,
31.5-31.8 GHz, in Region 2,
48.94-49.04 GHz, from airborne stations
50.2-50.4 GHz*,
52.6-54.25 GHz,
86-92 GHz,
100-102 GHz,
109.5-111.8 GHz,
114.25-116 GHz,
148.5-151.5 GHz,
164-167 GHz,
182-185 GHz,
190-191.8 GHz,
200-209 GHz,
226-231.5 GHz,
250-252 GHz. (WRC 03) -
5.341 In the bands 1 400-1 727 MHz, 101-120 GHz and 197-220 GHz, passive research is being conducted by some countries in a programme for the search for intentional emissions of extraterrestrial origin.
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US74 In the bands 25.55-25.67, 73-74.6, 406.1-410, 608-614, 1400-1427, 1660.5-1670, 2690-2700, and 4990-5000 MHz, and in the bands 10.68-10.7, 15.35-15.4, 23.6-24.0, 31.3-31.5, 86-92, 100-102, 109.5-111.8, 114.25-116, 148.5-151.5, 164-167, 200-209, and 250-252 GHz, the radio astronomy service shall be protected from unwanted emissions only to the extent that such radiation exceeds the level which would be present if the offending station were operating in compliance with the technical standards or criteria applicable to the service in which it operates. Radio astronomy observations in these bands are performed at the locations listed in US385.
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US246 No station shall be authorized to transmit in the following bands: 73-74.6 MHz, 608-614 MHz, except for medical telemetry equipment1 and white space devices,2 1400-1427 MHz, 1660.5-1668.4 MHz, 2690-2700 MHz, 4990-5000 MHz, 10.68-10.7 GHz, 15.35-15.4 GHz, 23.6-24 GHz, 31.3-31.8 GHz, 50.2-50.4 GHz, 52.6-54.25 GHz, 86-92 GHz, 100-102 GHz, 109.5-111.8 GHz, 114.25-116 GHz, 148.5-151.5 GHz, 164-167 GHz, 182-185 GHz, 190-191.8 GHz, 200-209 GHz, 226-231.5 GHz, 250-252 GHz.
1Medical telemetry equipment shall not cause harmful interference to radio astronomy operations in the band 608-614 MHz and shall be coordinated under the requirements found in 47 CFR 95.1119.
2White space devices shall not cause harmful interference to radio astronomy operations in the band 608-614 MHz and shall not operate within the areas described in 47 CFR 15.712(h).
Wiki entries
Radio Astronomy (1400-1427 MHz)
Current Use
1400–1427 MHz Neutral hydrogen (HI)
This band is one of the most important bands for radio astronomy, since it encompasses a fundamental spectral line of hydrogen, which is by far the most prevalent element in the Universe.
Neutral (non-ionized) hydrogen naturally emits (or absorbs) at the frequency of 1420.4058 MHz due to a "spin flip" transition in energy states. Referred to as the HI line (pronounced "H-one line"), it can be observed throughout the cosmos and is heavily used for probing conditions in our own Galaxy and in other galaxies.
Due to relative motions between us and the cosmic sources being observed, the HI line can be seen at frequencies other than its rest frequency of 1420.4058 MHz. In fact, it is believed that neutral hydrogen can be observed at such great distances (and therefore many billions of years in the past), that its signal would be redshifted to 100 MHz or even below as a result of the expansion of the Universe. The allocated range, 1400 - 1427 MHz, therefore encompasses only a small portion of the frequency range that is needed to observe HI throughout the Universe.
The line is sometimes also referred to as the 21 cm line, referring to its rest wavelength.
HI observations are made at many radio astronomy observatories worldwide.
Neutral (non-ionized) hydrogen naturally emits (or absorbs) at the frequency of 1420.4058 MHz due to a "spin flip" transition in energy states. Referred to as the HI line (pronounced "H-one line"), it can be observed throughout the cosmos and is heavily used for probing conditions in our own Galaxy and in other galaxies.
Due to relative motions between us and the cosmic sources being observed, the HI line can be seen at frequencies other than its rest frequency of 1420.4058 MHz. In fact, it is believed that neutral hydrogen can be observed at such great distances (and therefore many billions of years in the past), that its signal would be redshifted to 100 MHz or even below as a result of the expansion of the Universe. The allocated range, 1400 - 1427 MHz, therefore encompasses only a small portion of the frequency range that is needed to observe HI throughout the Universe.
The line is sometimes also referred to as the 21 cm line, referring to its rest wavelength.
HI observations are made at many radio astronomy observatories worldwide.
Soil Moisture Active Passive (SMAP) Satellite
Current Use
1400–1427 MHz SMAP passive radiometer
The Soil Moisture Active Passive (SMAP) satellite is a planned NASA satellite mission to monitor soil moisture around the globe. It is planned for launch in 2014.
As its name implies, the Soil Moisture Active Passive (SMAP) satellite uses active and passive radio systems to measure soil moisture around the globe. The spacecraft is in a sun-syncronous orbit that passes overhead of its target areas around 6 AM and 6 PM, approximately every 3 days at the equator and every 2 days at high latitudes.
SMAP's sensors can determine soil moisture down to a depth of approximately 5-10 cm. The active radar provides approximately 3 km resolution on the ground, using a 6 m antenna and measuring reflections in HH, VV, and HV polarization modes. The radar works in frequency hopping mode to avoid interference to and from aviation radars that operate in the same band. The instantaneous signal from the radar consists of two separate signals each of ~1.4 MHz bandwidth, separated by 5 MHz. It pulses every ~354 microseconds, for a duration of ~10-20 microseconds per pulse. The radar transmit power (not EIRP) is a few hundred watts.
SMAP will operate in a circular orbit of 670 km altitude. The ground footprint of the radar is approximately 1000 km. Resolution of the radar in low-resolution mode is approximately 40 km, and in high-resolution mode the resolution is approximately 3 km.
Soil moisture data can be used for improving numerical weather prediction, including seasonal climate prediction and rainfall prediction.
Like the European SMOS satellite, it is anticipated that SMAP's passive sensor will be subject to illegal RFI in the passive-only 1400-1427 MHz band.
As its name implies, the Soil Moisture Active Passive (SMAP) satellite uses active and passive radio systems to measure soil moisture around the globe. The spacecraft is in a sun-syncronous orbit that passes overhead of its target areas around 6 AM and 6 PM, approximately every 3 days at the equator and every 2 days at high latitudes.
SMAP's sensors can determine soil moisture down to a depth of approximately 5-10 cm. The active radar provides approximately 3 km resolution on the ground, using a 6 m antenna and measuring reflections in HH, VV, and HV polarization modes. The radar works in frequency hopping mode to avoid interference to and from aviation radars that operate in the same band. The instantaneous signal from the radar consists of two separate signals each of ~1.4 MHz bandwidth, separated by 5 MHz. It pulses every ~354 microseconds, for a duration of ~10-20 microseconds per pulse. The radar transmit power (not EIRP) is a few hundred watts.
SMAP will operate in a circular orbit of 670 km altitude. The ground footprint of the radar is approximately 1000 km. Resolution of the radar in low-resolution mode is approximately 40 km, and in high-resolution mode the resolution is approximately 3 km.
Soil moisture data can be used for improving numerical weather prediction, including seasonal climate prediction and rainfall prediction.
Like the European SMOS satellite, it is anticipated that SMAP's passive sensor will be subject to illegal RFI in the passive-only 1400-1427 MHz band.