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CX2SA > SATDIG 25.03.13 21:14l 786 Lines 30845 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. testing (Kevin Deane)
2. ANS-083 AMSAT News Service Weekly Bulletins (E.Mike McCardel)
3. satellite tracker update (Joseph Armbruster)
4. satellite los footprints (Joseph Armbruster)
5. Re: satellite los footprints (Gus)
6. Hawaii-FO-29 (John Fickes)
----------------------------------------------------------------------
Message: 1
Date: Sun, 24 Mar 2013 12:35:17 -0700
From: Kevin Deane <summit496@xxxx.xxx>
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] testing
Message-ID: <BLU174-W31E0305FD7BF28D82577E683D60@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
testing on fixed old computer...
Kevin
KF7MYK
------------------------------
Message: 2
Date: Sun, 24 Mar 2013 15:41:21 -0400
From: "E.Mike McCardel" <mccardelm@xxxxx.xxx>
To: Amsat - BBs <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] ANS-083 AMSAT News Service Weekly Bulletins
Message-ID:
<CAM5+sotn-udXE2eZz3kGu-qO3Bfh94L+Tham=JL7zHKOScyonA@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
AMSAT NEWS SERVICE
ANS-083
ANS is a free, weekly, news and information service of AMSAT North
America, The Radio Amateur Satellite Corporation. ANS reports on the
activities of a worldwide group of Amateur Radio operators who share
an active interest in designing, building, launching and
communicating through analog and digital Amateur Radio satellites.
Please send any amateur satellite news or reports to:
ans-editor@xxxxx.xxx
In this edition:
* Come See AMSAT at Dayton 2013
* Dayton Hamvention 2013 AMSAT Forum
* More 'AMSAT at Dayton' News
* ISS Expedition 35 Crew To Include Three Licensed Hams
* ARISS News
* [QB50] 5th European CubeSat Symposium - ESA sponsorship - Deadline
postponed
* March/April 2013 AMSAT Journal Heading for the Print Shop
* KiwiSAT - All systems are now flight ready
* New Swiss Small Satellite Launch System
* Raspberry Pi as WSPR transmitter up to 250 MHz
* Houston based WebSDR for 2m Ham Band
* AMSAT Helps at Monrovia HS Science Expo and ISS Downlink
* Music in Space Downlink With the International Space Station
* Argentine CubeBug-1 satellite will have amateur radio digipeater
SB SAT @ AMSAT $ANS-083.01
ANS-083 AMSAT News Service Weekly Bulletins
AMSAT News Service Bulletin 083.01
>From AMSAT HQ SILVER SPRING, MD.
March 24, 2013
To All RADIO AMATEURS
BID: $ANS-083.01
*****************************************************************
* Volunteers are needed to help at the AMSAT booth at Dayton. *
* Steve Belter N9IP, is looking for volunteers to help man the *
* AMSAT booth during the 2013 Hamvention. If you are willing *
* to help at the Hamvention, please send an e-mail by April 30 *
* to Steve Belter, n9ip@xxxxx.xxx. *
* *
* Monitor the 'AMSAT at Dayton Hamvention 2013' link on the new *
* AMSAT Web Site http://www.amsat.org for the latest AMSAT at *
* Dayton news and developments *
*****************************************************************
Come See AMSAT at Dayton 2013
The 2013 Dayton Hamvention, sponsored by the Dayton Amateur Radio
Association will be held this year on May 17-19, 2013. "Dayton" is
the largest hamfest in the United States, and AMSAT will be there
again this year.
AMSAT's theme for Dayton will be "AMSAT - A View to the Future."
Come see AMSAT in Ball Arena, right across from the ARRL area and
just inside the door from the Satellite Demonstration area.
The AMSAT booth will feature AMSAT Engineering, new publications,
new apparel, amateur satellite hardware and software. The AMSAT
Forum will be on Saturday May 18. Plan to visit all of the AMSAT
activities!
+ The booth will feature an engineering model of the 1U Fox Cubesat
+ AMSAT Publications
+ AMSAT Apparel
+ Station Hardware
+ The latest version SatPC32 tracking software
+ Renew your AMSAT membership at the AMSAT booth too.
[ANS thanks JoAnne Maenpaa, K9JKM for the above information]
---------------------------------------------------------------------
Dayton Hamvention 2013 AMSAT Forum
This year's AMSAT Forum will be held is on Saturday in Room 5,
from 1115
to 1330 EDT. There will be an open Q&A session after the talks.
Moderator: Alan Biddle, WA4SCA
Speakers:
"AMSAT Status Report." Barry Baines, WD4ASW, AMSAT-NA President,
will highlight recent activities within AMSAT and discuss some of the
challenges, accomplishments, and exciting projects of the
organization.
"A report on ARISS." Frank Bauer, KA3HDO, AMSAT-NA Vice President
for Human Spaceflight, will discuss amateur operations on the
International Space Station.
"AMSAT Fox Satellite Program," Tony Monteiro, AA2TX, AMSAT-NA
Engineering VP, will present the current Status of the AMSAT Fox
CubeSat Projects.
"The AMSAT-UK FUNcube CubeSat." Howard Long, G6LVB, AMSAT-UK
Committee Member, will discuss the FUNcube project which will enable
amateurs and students to use and learn about satellites.
"Amateur Satellites, Education, and You!" Mark Hammond, N8MH, AMSAT-
NA Educational Relations VP, will discuss what satellite operators
can do to support the educational goals of AMSAT.
[ANS thanks Alan WA4SCA for the above information]
---------------------------------------------------------------------
More 'AMSAT at Dayton' News
+ AMSAT Hotel
The cutoff date to book a room with the AMSAT group is April 25.
If you are interested in staying with AMSAT at Dayton, please call
Martha at the AMSAT Office at 301-589-6062.
+ Thursday Night Dinner and Beverages at Tickets Pub and Eatery
Thursday night, May 16, 1830-???? at the Tickets Pub and Eatery in
Fairborn, OH. This is a great chance to relax after a hard day's
travel or setting up the AMSAT display area. Very informal. Click
the 'AMSAT at Dayton Hamvention 2013' button on the new Web Site:
http://www.amsat.org.
+ AMSAT/TAPR Friday Night Banquet
AMSAT/TAPR Banquet on Friday night, May 17 is one of the main AMSAT
activities during the 2013 Hamvention at Dayton. Banquet tickets
will not be sold at the AMSAT booth during the Hamvention so reser-
vations must be made through the AMSAT Store. For the latest details
about the Banquet go to the 'AMSAT at Dayton Hamvention 2013' button
on the new Web Site: http://www.amsat.org. The link to the AMSAT
Store to purchase the Banquet tickets will be found there. Tickets
are $30 apiece.
+ Satellite Demonstration Area
AMSAT is encouraging everyone attending the 2013 Dayton Hamvention
to come by the Satellite Demonstration Area just outside of the Ball
Arena entrance for live demonstrations making contacts using the
amateur satellites. There will be AMSAT volunteers there to explain
how to make the contacts and during actual satellite passes. Lists of
satellite pass times will be posted in the satellite demonstration
area and at the AMSAT booth.
[ANS thanks AMSAT's 2013 Dayton Committee for the above information]
---------------------------------------------------------------------
ISS Expedition 35 Crew To Include Three Licensed Hams
A report posted on Space-Travel.com says Russian cosmonauts Pavel
Vinogradov, RV3BS and Alexander Misurkin and NASA astronaut Chris
Cassidy have arrived at the Baikonur Cosmodrome in Kazakhstan to
prepare for the March 29 launch to the International Space Station.
Their Soyuz spacecraft is to reach the ISS in a record six hours
due to a new fast-track launch trajectory.
The ISS will have a crew of six upon arrival of the Soyuz when Vino-
gradov, Misurkin and Cassidy join with Russian cosmonaut Roman Roman-
enko, Canadian astronaut Chris Hadfield, KC5RNJ/VA3OOG, and US astro-
naut Thomas Marshburn, KE5HOC are already aboard the space station.
See http://tinyurl.com/March29-Launch (Space-Travel.com) for their
orginal posting.
[ANS thanks Space-Travel.com for the above information]
---------------------------------------------------------------------
ARISS News
Recent ARISS Contacts
+ Christ the King School, Adelaide, South Australia, Australia on 20
March 2013
A successful ARISS Contact was made with with participants at Christ
the King School, Adelaide, South Australia, Australia on 20 Mar. The
contact began at approximately 07:15 UTC, and lasted for about 9
minutes and 30 seconds. The contact was a telebridge between OR4ISS
and IK1SLD and was audible over Italy and adjacent areas.
Established by the Sisters of the Good Samaritan, Christ the King
School, Warradale, is a small, Reception to Year 5 Catholic parish
school within the Brighton Parish in Adelaide. The school has
approximately 190 students across 7 classes. In the Catholic
tradition, they seek to provide a comprehensive Catholic education
to children in a caring, faith community.
+ Ann Richards School for Young Women Leaders, Austin, TX on 20
March 2013
A successful ARISS Contact was made with with participants at Ann
Richards School for Young Women Leaders, Austin, TX on 20 Mar. The
contact began at approximately 14:20 UTC, and lasted for about 9
minutes and 30 seconds. The contact was a telebridge between NA1SS
and VK6MJ and was audible over portions of Australia and adjacent
areas.
The Ann Richards School for Young Women Leaders is a unique all-
girls school founded to educate young women and give them the
confidence and skills necessary to succeed in college, in their
careers, and in their communities. They are a public school in the
Austin Independent School District serving over 700 girls in 6th
through 12th grade. The girls partake and excel in engineering design
projects and robotics competitions. The demographics of our student
body mirror that of our local community. During the 2011 - 2012
school year, 61% percent of our students were Hispanic, 22% are
Caucasian, 13% were African-American, 3% were Asian-American and 1%
were American Indian/Alaskan Native. Two hundred of the girls were
gathered as 10 of their peers asked questions on behalf of all grade
levels during the ARISS contact.
+ UA Huntsville Space Hardware Club, Huntsville, AL, on 21 March 2013
A successful ARISS Contact was made with with participants at UA
Huntsville Space Hardware Club, Huntsville, AL, on 21 Mar. The
contact began at approximately 15:50 UTC, and lasted for about 9
minutes and 30 seconds. The contact was a direct between NA1SS and
K4UAH and was audible over portions of the U.S.
The Space Hardware Club is a UA Huntsville student organization. The
club is student run and is strictly volunteer. Using the capacities
of a multi-disciplinary team of engineering to conceptualize, design,
build, test and fly flight hardware for orbital spaceflight, high
altitude ballooning, competitive mock-satellite design, build, launch
competitions, and other space related engineering problems.
Involvement in The Space Hardware Club allows students to experience
real life time sensitive deadlines, and design payloads to mission
specification. The students learn to design mechanical structures,
software, and circuit boards while considering thermal forces, shock
loads, and other realistic environmental limitations.
Upcoming ARISS Contacs For This Week
+ Thornton Middle School, Katy, TX on 25 Mar. The event is scheduled
to begin at approximately 15:39 UTC. The duration of the contact is
approximately 9 minutes and 30 seconds. The contact will be direct
between NA1SS and KF5NZD. The contact should be audible over portions
of the U.S. Interested parties are invited to listen in on the 145.80
MHz downlink. The contact is expected to be conducted in English.
+ Des Cardinaux School, Sainte-Rose, Laval, Quebec, Canada on 26
Mar. The event is scheduled to begin at approximately 13:13 UTC. The
duration of the contact is approximately 9 minutes and 30 seconds.
The contact will be a telebridge between NA1SS and K6DUE. The contact
should be audible over the east coast of the U.S. Interested parties
are invited to listen in on the 145.80 MHz downlink. The contact is
expected to be conducted in French.
[ANS thanks ARISS for the above information]
---------------------------------------------------------------------
[QB50] 5th European CubeSat Symposium - ESA sponsorship - Deadline
postponed
Cem O. Asma, PhD, Aeronautics & Aerospace Dept von Karman Institute,
reports, "We have good news regarding the 5th European CubeSat
Symposium that
will be held on 3-5 June 2013 at Brussels, Belgium. The Education
Office of European Space Agency has kindly offered scholarships to
selected students to attend the European CubeSat Symposium. More
information on the rules and how to apply are given at the Symposium
web site:
https://cubesatsymposium.eu/
We have therefore decided to postpone the deadline of abstract
submission to 29 Mar 2013 so that those who consider an ESA
sponsorship can apply as well."
[ANS thanks Cem O. Asma, PhD for the above information]
---------------------------------------------------------------------
March/April 2013 AMSAT Journal Heading for the Print Shop
AMSAT Journal Editor, JoAnne K9JKM reports that the March/April
2013 issue is on its way to the print shop this week. It should
reach your mailbox in early to mid-April. This issue features two
technical projects, operating features, and the latest news from
AMSAT's officers.
We'll update you on all the content next week when the March/April
Issue is completed, packed up, and ready for delivery.
Thanks for all the help from our Journal Editorial Team: Douglas
Quagliana, KA2UPW/5; Mike Sedlak, K4ERA; Bernhard Jatzeck, VA6BMJ;
Bill Hook, W3QBC, and Martha at the AMSAT Office.
The AMSAT Journal is pleased to publish your articles and photos of
satellite operations and all aspects of amateur radio in space.
Send your ideas and questions to journal at amsat.org.
[ANS thanks AMSAT Journal Editor JoAnne Maenpaa, K9JKM for the above
information]
---------------------------------------------------------------------
KiwiSAT - All systems are now flight ready
The KiwiSAT website reports that all hardware is complete and the
KiwiSAT micro-satellite is operational. Final integration to launch
ready awaits completion of command and control testing.
They say software is being developed and launch negotiation is
underway in New Zealand. Earlier reports indicated that $1 million
was required for a launch to a 700 km orbit.
Read the status report dated March 13, 2013 at
http://www.kiwisat.org.nz/status.html
[ANS thanks Trevor M5AKA and AMSAT-UK for the above information]
---------------------------------------------------------------------
New Swiss Small Satellite Launch System
Swiss Space Systems ? S3 a new Swiss aerospace company, was
officially inaugurated in Payerne on Thursday, March 14, in the
presence of representatives of the national authorities and of
prestigious Swiss and international partners such as the ESA,
Dassault Aviation, the Von Karman Institute, Sonaca, Meggitt and
Stanford University. S3 aims to develop, build, certify and operate
suborbital space shuttles dedicated to launching small satellites,
enabling space access to be made more democratic thanks to an
original system with launching costs reduced to a quarter of the
present cost. The first test launches are planned to be carried out
by the end of 2017.
The Swiss Space Systems launch model uses an Airbus A300, an
aircraft already certified for zero gravity flights, to take the
shuttle up to 10,000m on its back; the shuttle will then be launched
from there. Combining the internal architecture developed by the
French company Dassault for Hermes with the external architecture
developed by the Belgian companies Sonaca and Space Application
Services will develop the shuttle. Discussions are at an advanced
stage concerning the engine supplier. The shuttle-drone will take
care of the next part of the ascent up to an altitude of 80km, the
height at which the upper stage will be launched in order to put the
satellites into orbit. Once this operation has been completed, the
shuttle will return to earth by gliding towards its launch airport,
where it will be taken care of by the maintenance teams who will
prepare it for a new launch.
S3 say agreements have already been signed for four launches for the
Von Karman Institute.
How will the in-orbit delivery of small satellites work ? Video at
http://tinyurl.com/b27atko
Swiss Space Systems ? S3 http://www.s-3.ch/
[ANS thanks AMSAT-UK for the above information]
---------------------------------------------------------------------
Raspberry Pi as WSPR transmitter up to 250 MHz
Guido PE1NNZ has released code that he says enables the Raspberry Pi
to operate as a WSPR transmitter at HF and VHF.
Guido has modified the WsprryPi code originally developed by Dan
Ankers MD1CLV. He says the Raspberry Pi requires just a Low Pass
Filter (LPF) and antenna connected to the GPIO4 pin in order to
function as a WSPR transmitter.
The PE1NNZ code and binary is available at
https://github.com/threeme3/WsprryPi
Turning the Raspberry Pi into an FM Transmitter
http://www.southgatearc.org/news/march2013/
turning_the_raspberry_pi_into_an_fm_transmitter.htm
Dan Ankers MD1CLV WSPR
http://m0xpd.blogspot.co.uk/2013/01/raspberry-whispers.html
WSPR on the Raspberry Pi
http://www.southgatearc.org/news/march2013/
wspr_on_the_raspberry_pi.htm
[ANS thanks Southgate Amateur radio News for the above information]
---------------------------------------------------------------------
Houston based WebSDR for 2m Ham Band
Thomas Krahn KT5TK has made available a Houston-based Web Software
Defined Radio for the 144-146 MHz amateur radio band.
The WebSDR receiver is located in the 8th floor of a Houston office
building. The receiver is a simple RTLSDR dongle with an Elonics E4000
tuner. The brand is: Terratec NOXON DAB/DAB+ USB dongle (rev 2).
Currently a telescopic antenna is being used but it's planned to
change to a bi-quad antenna.
Thomas notes that the Houston AMSAT NET can be heard on Tuesdays at
8pm Central Time (Wednesday 0100 UT) 0n 145.470 MHz FM. (Also
available on Echolink AMSAT node.)
The Houston 2m WebSDR is available at
http://websdr.tkrahn.com:8901
[ANS thanks Southgate ARC for the above information]
---------------------------------------------------------------------
AMSAT Helps at Monrovia HS Science Expo and ISS Downlink
On Saturday, March 2, the Pasadena Radio Club participated in the
Monrovia High School Science Expo with the help of local AMSAT
members.Set up started at 8 am and the display began at 10. Tom Berne
gave students the opportunity to talk over amateur radio while
Robert and Irene Allen and Kate Hutton transmitted radiograms. Tom
Mikkelsen, Tim LaMarca, and Dale Hunzeker demonstrated amateur radio
satellite communications with an AMSAT satellite simulator and a
satellite receiving station. All spent considerable time answering questions
and sharing their ham radio experiences.
Other actives at the Science Expo included a FIRST Robotics
competition, demonstrations by the Remote Control Aircraft Club, and
booths from Sidewalk Astronomers, NASA, Planetary Society, FTC/FRC
Robotics, and Miachi/UniTek. Stargazing activities continued into the
evening.
Science Expo activities continued on Tuesday, March 5, with a NASA
sponsored live International Space Station downlink. Over one
thousand 5th - 12th grade Monrovian students watched as three
astronauts "floated" inside the space station while answering
students' questions. Tim LaMarca, Jutti Marsh, and Dale Hunzeker were
in the audience. These activities are examples of ways amateur radio
can work with schools in STEM (Science, Technology, Engineering, and
Mathematics) education.
[ANS thanks Dale L. Hunzeker, KJ6VUC for the above information]
---------------------------------------------------------------------
Music in Space Downlink With the International Space Station
Join NASA's Johnson Space Center, or JSC, Digital Learning Network for
a live International Space Station downlink with astronaut Chris
Hadfield, space station commander. Commander Hadfield and students
from the Pasadena Independent School District's Pearl Hall Elementary
will explore the many cultures and music surrounding the International
Space Station partners. Students will perform songs at JSC with
astronaut Dan Burbank and with space station astronaut Chris Hadfield.
Students from Pearl Hall Elementary in Pasadena, Texas, and the Chris
Hadfield Public School in Ontario, Canada, will speak to Chris while
exploring about the connection between the arts and science,
technology, engineering and mathematics.
Watch the webcast live on March 27, 2013, from 2:30-3:45 p.m. CDT* by
clicking on the link below.
http://tinyurl.com/2aufnge
Questions about the program may be directed to
Patricia Moore at patricia.l.moore@xxxx.xxx.
*The webcast time is subject change due to communication with the
space station. Please visit http://dln.nasa.gov for the most recent
information.
[ANS thanks NASA Education Express Message -- March 21, 2013
---------------------------------------------------------------------
Argentine CubeBug-1 satellite will have amateur radio digipeater
CubeBug-1 is the first technology demonstration mission for a new
CubeSat platform design (mechanics, hardware and software) intended
to be released as Open Source and Open Hardware for its use in
Amateur projects, University projects and research labs.
The project is sponsored by the Argentinian Ministry of Science,
Technology and Productive Innovation.
Payloads on this first mission include:
? an ARM based on-board computer
? a nano-reaction wheel with its driver circuit
? a low resolution camera
all based on COTS components
CubeBug-1 is a 2U CubeSat and the team are planning to use half
duplex communications on 437.445 MHz with 9k6 GMSK data. Telemetry
information is at http://1.cubebug.org/coms/telemetry
After the technology demonstration part of the mission is over, the
satellite will enter a mode that will include services to the Amateur
radio community, including a Digipeater, science data downloads from
the payload (including images if possible).
CubeBug-1 is expected to launch on a Long March CZ-2D rocket from
the Jiuquan Space Center on April 28, 2013. Other satellites on the
same launch include NEE-01 Pegasus and TURKSAT-3USAT.
Watch a CubeBug-1 video at http://vimeo.com/56055215
CubeBug-1 website http://1.cubebug.org/
[ANS thanks AMSAT-UK for the above information]
In addition to regular membership, AMSAT offers membership in the
President's Club. Members of the President's Club, as sustaining
donors to AMSAT Project Funds, will be eligible to receive addi-
tional benefits. Application forms are available from the AMSAT
Office.
Primary and secondary school students are eligible for membership
at one-half the standard yearly rate. Post-secondary school students
enrolled in at least half time status shall be eligible for the stu-
dent rate for a maximum of 6 post-secondary years in this status.
Contact Martha at the AMSAT Office for additional student membership
information.
73,
This week's ANS Editor,
EMike McCardel, KC8YLD
kc8yld at amsat dot org
------------------------------
Message: 3
Date: Mon, 25 Mar 2013 00:27:45 -0400
From: Joseph Armbruster <josepharmbruster@xxxxx.xxx>
To: "amsat-bb@xxxxx.xxx BB" <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] satellite tracker update
Message-ID: <7D82F32B-6F75-4B51-A805-3064B2724712@xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
All,
I've been hacking away at my google earth based satellite tracker. I
received several responses to this, so I wanted to send out a brief update
to the bb. I cleaned the project page up and added a formal download, this
way you do not need git to get started. I added some documentation to the
wiki, including installation instructions and inner-workings. This content
is subject to change by the hour, so for now take it with a grain of salt.
Since the last email, I have implemented the following:
- Ground Stations: Google Earth Satellite Tracker - Ground Stations U...
- Line of Sight Indicators: Google Earth Satellite Tracker - Line of Sight
Upd...
If you have any questions, let me know.
Joseph Armbruster
------------------------------
Message: 4
Date: Mon, 25 Mar 2013 11:15:35 -0400
From: Joseph Armbruster <josepharmbruster@xxxxx.xxx>
To: "amsat-bb@xxxxx.xxx BB" <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] satellite los footprints
Message-ID: <430FA79B-7265-468F-BB36-3651F7C15D37@xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
I can not decide how to implement ground footprints with my google earth
satellite tracker. I figured, since I can't make up my mind, I should get a
second (and third, and fourth) opinion. For this thread, I would like to
discuss how satellite ground-footprints should be implemented. A quick
brainstorm led me to three possible implementations (I am leaning towards
3). For each of these, I assume that a geographic line-of-sight footprint
is desired with no RF characteristics taken into consideration:
option 1 : assume a spherical earth model and project a polygon downwards
towards the footprint
- note: this is obviously the easiest approach but will result in the most
error
option 2 : assume an ellipsoidal earth model and project an irregularly
shaped polygon downwards towards the footprint
- note: this is arguably more difficult than option 1 and would result in
less error
option 3 : use a digital elevation model and an ellipsoidal model to
cull-out regions that are not visible due to geographic features and project
an irregularly shaped polygon downwards towards the footprint
- note: In this case, our footprint polygon would have holes cut out for the
regions that are culled out by mountain ranges, canyons / etc... Obviously,
this would be the most difficult to implement but would likely be the best
visual representation. The problem is, I would never dream of distributing
DEMs for the entire Earth with my tool, even DTED0 would be absurd in my
opinion. I could make the elevation queries accessible using a web-service,
but then the user would be tied to the internet. The other option would be
to allow the users to download their elevation data into a cache, then the
tool would just load / use it. This way the user would only have to obtain
the elevation data for their region of interest. Maybe that would be the
best approach? I am open to suggestions!
If you have any experience visualizing footprints, please let me know. I
would be interested in hearing your lessons-learned. These are what the
line-of-sight indicators look like right now: Google Earth Satellite
Tracker - Line of Sight Update
I am open to comments and suggestions,
Joseph Armbruster
------------------------------
Message: 5
Date: Mon, 25 Mar 2013 13:22:43 -0400
From: Gus <8p6sm@xxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: satellite los footprints
Message-ID: <515087E3.5000801@xxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I would suggest you go with #1 or #2. The added complexity of method #3
probably won't pay any significant dividends in practical terms. You
could always implement #3 for version II. :-)
Will you be considering squint? Frankly, I'm not sure any current
satellites are using antennas where squint would play a part.
Regards...
On 03/25/2013 11:15 AM, Joseph Armbruster wrote:
> I can not decide how to implement ground footprints with my google earth
satellite tracker. I figured, since I can't make up my mind, I should get a
second (and third, and fourth) opinion. For this thread, I would like to
discuss how satellite ground-footprints should be implemented. A quick
brainstorm led me to three possible implementations (I am leaning towards
3). For each of these, I assume that a geographic line-of-sight footprint
is desired with no RF characteristics taken into consideration:
>
> option 1 : assume a spherical earth model and project a polygon downwards
towards the footprint
>
> - note: this is obviously the easiest approach but will result in the most
error
>
> option 2 : assume an ellipsoidal earth model and project an irregularly
shaped polygon downwards towards the footprint
>
> - note: this is arguably more difficult than option 1 and would result in
less error
>
> option 3 : use a digital elevation model and an ellipsoidal model to
cull-out regions that are not visible due to geographic features and project
an irregularly shaped polygon downwards towards the footprint
>
> - note: In this case, our footprint polygon would have holes cut out for
the regions that are culled out by mountain ranges, canyons / etc...
Obviously, this would be the most difficult to implement but would likely be
the best visual representation. The problem is, I would never dream of
distributing DEMs for the entire Earth with my tool, even DTED0 would be
absurd in my opinion. I could make the elevation queries accessible using a
web-service, but then the user would be tied to the internet. The other
option would be to allow the users to download their elevation data into a
cache, then the tool would just load / use it. This way the user would only
have to obtain the elevation data for their region of interest. Maybe that
would be the best approach? I am open to suggestions!
>
> If you have any experience visualizing footprints, please let me know. I
would be interested in hearing your lessons-learned. These are what the
line-of-sight indicators look like right now: Google Earth Satellite
Tracker - Line of Sight Update
>
> I am open to comments and suggestions,
> Joseph Armbruster
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
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--
73, de Gus 8P6SM
Barbados, the easternmost isle.
------------------------------
Message: 6
Date: Mon, 25 Mar 2013 12:41:49 -0500
From: John Fickes <kc0bmf@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Hawaii-FO-29
Message-ID:
<CAG-+cOYFsi08zj0VwJTrTietq+nmj0JiJhEk0x6oE=ZRTOVgRg@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Any Hawaii hams around for FO-29 pass today (3-25) 19:30utc to Iowa EN31
Thanks John KC0BMF
------------------------------
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End of AMSAT-BB Digest, Vol 8, Issue 93
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