Join AMSAT-UK

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Founded in 1975 AMSAT-UK is a voluntary organisation that supports the design and building of equipment for amateur radio satellites.

AMSAT-UK initially produced a short bulletin called OSCAR News to give members advice on amateur satellite communications. Since those early days OSCAR News has grown in size and the print quality has improved beyond recognition. Today, OSCAR News is produced as a high-quality quarterly colour A4 magazine consisting of up to 40 pages of news, information and comment about amateur radio space communications.

The new lower-cost E-membership provides OSCAR News as a downloadable PDF file giving members the freedom to read it on their Tablets or Smartphones anytime, anyplace, anywhere.

AMSAT-UK FUNcube Mission Patch Rev4 20100609

AMSAT-UK FUNcube Mission Patch

An additional advantage is that the PDF should be available for download up to 2 weeks before the paper copy is posted.

Take out Electronic Membership or Postal Membership at the AMSAT-UK shop

E-members can download their copies of OSCAR News from http://www.amsatuk.me.uk/on

A sample issue of OSCAR News can be downloaded here.

Amateur Satellite Tutorial Videos

David Casler KE0OG has released a series of tutorial videos for the US Extra class license two of which cover amateur radio satellites.

The first deals with Orbital Mechanics and the second covers the radio aspects of amateur satellites.

Watch Extra Lesson 2.3, Amateur Satellites (Part 1)

Watch Extra Class Section 2.3 Satellite Operations (Part 2)

See the other tutorial videos at https://www.youtube.com/user/davecasler/videos

MEO and HEO satellite orbits

Orbits - Illustration by B. Jones, P. Fuqua, J. Barrie, The Aerospace Corporation

Orbits – Illustration by B. Jones, P. Fuqua, J. Barrie, The Aerospace Corporation

David Bowman G0MRF describes the coverage area that might be provided by an amateur radio Medium Earth Orbit (MEO) satellite (MEOSAT). He suggests there is a region of space that would be optimum for such satellites.

The Van Allen radiation belts are separated into two layers. The lower layer is comprised of high energy protons between 600 and 6000km. The second belt is essentially electrons and that occupies altitudes above 12,000km.  So a MEOSAT could avoid damaging radiation by orbiting in the “safe zone” between 7,000 and 11,000 km.

Read David’s MEO article at http://g0mrf.com/MEOSAT.htm

Watch the MEO satellites presentation given to the AMSAT-UK International Space Colloquium 2009
Video made by the British Amateur Television Club (BATC) Slides here

Elliptical Satellite Orbits

The paper Revisiting elliptical satellite orbits to enhance the O3b constellation by Lloyd Wood, Yuxuan Lou and Opeoluwa Olusola of the University of Surrey is now available for download.

Orbital altitudes of satellite systems

Orbital altitudes of satellite systems

Early low-orbiting satellites were launched into Highly Elliptical Orbits (HEO) as a result of not having much control over trajectory. Circular orbits with minimal eccentricity offer consistent altitudes, with the benefits of consistent free space losses and link budgets throughout the orbit, and soon became the norm. Highly elliptical orbits fell from favor for communications use.

Highly elliptical orbits can be used to provide targeted satellite coverage of locations at high latitudes. We review the history of use of these orbits for communication. How elliptical orbits can be used for broadband communication is outlined. We propose an addition of known elliptical orbits to the new equatorial O3b satellite constellation, extending O3b to cover high latitudes and the Earth’s poles. We simulate the O3b constellation and compare this to recent measurement of the first real Internet traffic across the newly deployed O3b network.

Download the paper from http://arxiv.org/pdf/1407.2521v1 Source page http://arxiv.org/abs/1407.2521

Orbit Perturbation Analysis

The orbits of satellites at altitudes above 2500 km can decay faster than might at first be expected. The Dash-2 satellite was a 1 kg 2.5 meter diameter balloon launched on July 19, 1963 with the West Ford Needles. The 3500 km orbit, originally circular, increased in eccentricity rapidly under the action of solar radiation pressure. Dash 2 reentered the Earth’s atmosphere less than 8 years later on April 12, 1971.

Read the paper Atmospheric Density Variations at 1500-4000 km Height Determined from Long Term Orbit Perturbation Analysis by Bruce R. Bowman
http://sol.spacenvironment.net/~JB2008/pubs/JB2006_AAS_2001_132.pdf

Medium Earth Orbiting satellites by David Bowman G0MRF http://g0mrf.com/MEOSAT.htm

MEO slides from the presentation given by David Bowman G0MRFDownload PDF Here

Earth’s Safe Zone http://www.nasa.gov/vision/universe/solarsystem/safe_zone.html

Amateur Radio CubeSat to HEO ? by Brent Salmi KB1LQD
https://amsat-uk.org/2013/09/02/amateur-radio-cubesat-to-heo/

The AMSAT-UK International Space Colloquium is being held at the Holiday Inn, Guildford, GU2 7XZ on July 26-27, 2014. The event is open to all, further details at https://amsat-uk.org/colloquium/colloquium-2014/

Facebook plans Internet satellites

Internet platforms at different altitudesMark Zuckerberg says Facebook’s Connectivity Lab plans to build satellites to bring the Internet to more people.

“In our effort to connect the whole world with Internet.org, we’ve been working on ways to beam internet to people from the sky.

Today, we’re sharing some details of the work Facebook’s Connectivity Lab is doing to build drones, satellites and lasers to deliver the internet to everyone.

Our goal with Internet.org is to make affordable access to basic internet services available to every person in the world.”

“Our team has many of the world’s leading experts in aerospace and communications technology, including from NASA’s Jet Propulsion Lab and Ames Research Center. Today we are also bringing on key members of the team from Ascenta, a small UK-based company whose founders created early versions of Zephyr, which became the world’s longest flying solar-powered unmanned aircraft. They will join our team working on connectivity aircraft.”

Read his full post at https://www.facebook.com/zuck/posts/10101322049893211

In this paper Mark describes the challenges and opportunities of a new generation of connectivity platforms: https://fbcdn-dragon-a.akamaihd.net/hphotos-ak-ash3/t39.2365-6/851574_611544752265540_1262758947_n.pdf

Ofcom Consultation: 146-147 MHz for Amateur Radio use in UK

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Ofcom has published a consultation on the release of around 6 MHz of very high frequency (VHF) spectrum in the 143 to 169 MHz band, which has been returned for civil use.

The consultation says:

1.7 As demand for both operational and potential future services in the short to medium term is likely to be low we are also proposing to permit temporary access to 1 MHz of this spectrum (146 to 147 MHz) for Amateur Radio use, until such a time as it is needed by Business Radio or other services. Should additional spectrum be needed to meet operational requirements, we will remove the temporary allocation. Amateur Radio use of this frequency will be on a non-protection/ non-interference basis and will be subject to some geographical restrictions to ensure that there is no interference to neighbouring countries. We propose that the authorisation will be implemented by an individual Notice of Variation (NoV) to the Amateur Radio licence.

The consultation summarises responses to an earlier Call for Input on the release of spectrum in England, Wales and Northern Ireland between 143 and 156 MHz spectrum. Today’s document also encompasses spectrum that has been returned for civil use between 168 MHz and 169 MHz. Since the Call for Input was published, this spectrum is now available on a UK-wide basis.

The consultation explains Ofcom’s proposed approach to allocating the released spectrum, including a proposal that spectrum be made available on a first-come-first-served basis through Ofcom’s current Business Radio licence products.

Responses to the proposals are invited by 26 May 26, 2014, make your response at
http://stakeholders.ofcom.org.uk/consultations/vhf-143-169mhz/howtorespond/

Consultation document
http://stakeholders.ofcom.org.uk/binaries/consultations/vhf-143-169mhz/summary/VHF_consultation.pdf

Consultation: Responses to the Call for Input and Consultation on next steps of the release of spectrum within the frequency ranges 143 MHz to 169 MHz
http://stakeholders.ofcom.org.%20uk/consultations/vhf-143-%20169mhz/