From IT Wire:
The Government has announced its response to the Spectrum Review undertaken by the Department of Communications, in conjunction with the Australian Communications and Media Authority (ACMA).
The Government says it will implement the recommendations of its review of the way Australia’s spectrum is managed.
The review is now complete and is available here.
From the ARRL newsletter
A Virginia Tech undergraduate researcher and radio amateur has used Super Dual Auroral Radar Network (SuperDARN) and Reverse Beacon Network (RBN) data to study how solar flares impact HF radio propagation over the entire dayside — the time Earth is in sunlight — with communication loss related to both flare intensity and distribution. Carson Squibb, KM4MBQ, recently summarized his findings in a poster presentation, “Dayside Ionospheric Response to X-Class Solar Flare Events Observed with Reverse Beacon Network High Frequency Communication Links.” As most HF operators understand, higher-intensity flare events can cause complete signal loss on HF, while weaker flares may only partly inhibit radio propagation.
According to Squibb’s poster, a solar flare is an event in which the Sun emits high levels of ultraviolet and X-ray radiation, resulting in increased photoionization in the ionosphere, primarily in the D-layer, which is largely responsible for absorption of HF radio waves. So, as ionization increases during flare events, communication can be diminished or lost completely. Such fadeouts can occur in minutes, while subsequent recovery can take hours, “which is why understanding these flare effects is of critical importance,” Squibb said.
According to Squibb, the rate of communication loss is related to the increase in X-ray intensity, and the period of recovery is influenced by both flare intensity and the rate of decline in X-ray flux after peaking. Squibb determined that lower frequencies experience fades in propagation prior to the flare peak, with recovery taking longer, while the degree of loss is more severe as frequency decreases.
Squibb’s poster explains that SuperDARN detects a ground-scatter band that results from waves reflecting from the ionosphere and ground, and that this band is degraded during solar flare events. To determine the spatial distribution of flare effects, Squibb used data from four radars across North America. He used the RBN — an array of passive receivers which detects Amateur Radio signals and posts identifiable call signs on the Internet — to measure HF communication. Squibb chose 3.5, 7, 14, 21, and 28 MHz for study. Xâray flux data within the 0.05-0.4 nm and 0.1-0.8 nm ranges were taken from the GOES-15 geostationary weather satellite.
Squibb said future research should focus on quantifying the relationship between flare characteristics and HF signal fadeout.
Squibb conducted his research under the guidance of graduate student Nathaniel Frissell, W2NAF, and SuperDARN group supervisors Jo Baker and Mike Ruohoniemi, as part of his participation in the Research Experiences for Undergraduates (REU) program sponsored by the National Science Foundation and hosted by the Center for Space Science and Engineering Research (Space@VT). His co-authors included Magda Moses, KM4EGE, of Virginia Tech, and Robyn Fiori of the Canadian Space Weather Forecast Center.
As part of the GPSDO project I’ve been working on using a graphical display I picked up from Futurlec several years ago, a 128×64 Blue GLCD (CM12864-2) which uses the KS0108 chipset.
As I want to drive this from a Beaglebone Black I’ve opted to use a GLCD Backpack from Sparkfun to simplify the hookup and interfacing, sending serial commands should be far easier than sorting though GPIO… at least it _should_ have been.
The first issue is the backpack pinouts don’t match the pin layout on the LCD I have, so I’ll have to make up an adapter board. Some breadboard does the job while developing so not a huge issue there.
The standard firmware comes with a number of simple operations for displaying text and some basic geometry operations, functional but nothing flash.
Unfortunately I found the standard firmware to be a little slow on the refresh rate and came with two standard fonts, big and bigger.
A little research found an updated set of firmware listed at the bottom of the page.
I modified this to include a small 3*5 font reminiscent of 80’s era computer games in place of the standard ‘large’ font, and quickly put together a nice summary page for the state of the GPSDO.
There are some minor dislikes for the font, for example the ‘H’ and ‘N’ characters are identical, but it works well enough that I may live with it.
The software was written in perl and may be shared later, its all very straight forward decoding of the GPS messages and sending serial data to the display so nothing complex in there. I have included a ‘deltacache’ which detects data changes so only updates are posted to the LCD to conserve the limited serial bandwidth and avoid buffer overflows as I don’t have any flow control at this stage as the ‘TX’ pin isn’t connected to the BBB to avoid damaging the 3v IO pin.
All in all I’m happy with the results so far. I still have a lot of work to do but this is a promising result.
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Now that I have confirmed the Thunderbolt Trimble is working nicely down to 3.5ppt (3.5E-10) and getting more accurate as time goes on its time to put it in a box so its more durable and generally more usable. My plan is to add a Beaglebone Black, LCD and Keypad for display and control of the system alongside network.
* LCD to display the lock status, accuracy and any alarm conditions.
* Keypad for local interaction with the system.
* NTP server based off the GPS and PPS feed.
* Network support for NMEA and TSIP data from the GPS module.
* Multiple filtered and amplified 10MHz outputs to feed test equipment and VFO’s.
The best part is most of it is based on kit I already have in the junk box.
On the software level a number of existing open source projects will be used to build system:
The main components being:
* GPSD will listen to the serial connection and receive the data from the GPS module, this daemon will be configured to start receiving the data immediately rather than waiting for a client connection so it can feed the NTP server.
This is a nice tool for working with the GPS with _almost_ no configuration required to get it working, it also nice to be able to feed the data from a single GPS to multiple targets without having to code around it.
* NTPD will listen to the GPS and PPS data via shared memory alongside several external ntp servers to establish the base time. This time will be available to external systems, when tuned it should be reasonably accurate. A minor modification to the Beaglebone will be required to significantly increase the accuracy of this service.
This is a fairly standard protocol. Chrony may be used instead given its more suitable for a low power system, time will tell.
* An embedded network client will most likely be built to feed the NMEA data into my IC-7100 transceiver for an accurate position fix. I have the data, so why not 😉
* A GPSD monitor will be developed to process the TSIP data for analysis (ADEV) and reporting on the attached LCD and via a web interface. The TSIP data has to be processed as the NMEA and JSON feeds produced by GPSD don’t include the additional metrics and alarms states sent from the GPS unit.
* All performance data will be stored in a Round Robin Data Base for reporting over time. This is important in understanding the long term performance of the GPSDO.
* LCDProc will be run to control the graphical LCD, displaying system, performance, and GPS status information. An attached keypad will be processed by LIRC and used to switch displays and perform configuration options without requiring an external PC. (i.e. Run Self Survey).
* GPSCTL is part of the GPSD package and will be used to send commands to the GPS unit for any configuration changes to the applied.
* And finally, a NODE.js interface will be coded to make the whole lot available via a web interface, simply because its time I learnt node…
There’s a lot in this little project, I’m really enjoying it so far.
The Thunderbolt Trimble arrived during the week, and after 48 hours for the self survey and to calibrate the internal PID loops its delivering a nice level of performance, the only disagreement with my HP 5335 Counter is down in the 10E-15 territory which is outside the resolution of this GPSDO.
The entire ensemble is, however, untidy. The GPS unit itself is in a small metal box, I have an external laptop power supply to provide the required voltage levels, serial connections, antenna connection, and then the outputs… untidy. It gets worse when I run a serial cable to monitor it via Lady Heather or similar.
I want to be able to leave this system running all the time, so it needs to go in a box and include its own monitoring. I also don’t want to spend a fortune here but I also wanted rack mount, and sometimes things just work out with a 2RU rackmount PLA project box at the local Jaycar for $20 😉
The internals for the box are mostly coming out of my ‘junk’ box, bits and peices I’ve collected over the years, including:
* Beaglebone Black
This board will be used to ‘monitor’ the GPS unit and provide network connectivity for ntp etc. This board will also run the display, keypad, etc so I can monitor the system without using an external PC.
* USB to Serial converter.
An old prolific (PL2303) USB<->Serial converter will be used, while strictly not necessary it removes the need for level conversions here and the BBB has a usb port readily available.
* CM12864-2 128×64 White on Blue Graphical LCD bought for a project several years ago and never used. This will make a nice display for this project.
* 16 character keypad picked up at a field day somewhere. I don’t _need_ 16 keys, but it looks ok and will support any additional functionlity I may add later. Its been sitting in a drawer for years so the price is right 😉
*Amphenol case mount BNC connectors, I picked up a box of ~20 of these for $2 at a field day recently.
* level converters should these be necessary, I suspect they won’t be needed.
I have ordered on additional item:
Sparkfun Graph LCD serial backpack for the display, simply because this will be more convenient wiring the display up to the BBB.
The next steps:
* Code up a parser for the messaging coming from the GPS.
* Wire up the keypad and code up a driver using GPIO pins.
* Wire up the display and see if I can find a driver somewhere, I suspect I can.
* Code away.
all up the boxing project will cost approximately $50 out of pocket given I already have all the key components, and $30 of that is the backpack for the LCD panel to save some time.
This very special activation of the ANZAC callsign is expected to happen over this weekend. There will be a level of uncertainty in being able to operate mostly due to the Antarctic weather. Currently there is a blizzard occurring with 100 knot winds. I will keep sending information via email and WIA web site www.wia.org.au
Fred Swainston VK3DAC WIA ANZAC Event Co-ordinator
The activation of VI0ANZAC on Casey Station in the Australian Antarctic Territory is due to start operation, as part of the Wireless Institute of Australia ANZAC 100 program.
Doug VK0DMV is working at Casey Station and has great pleasure in activating the VI0ANZAC callsign. His role keeps him extremely busy and can only operate when his duties allow. This will mean that some published operation time may not occur due to operational requirements and the weather conditions.
VI0ANZAC will use the commercial Qmac HF90 transceiver with an output power of 50 watts into a dipole antenna.
Doug thanks both the WIA and the Australian Antarctic Division for this opportunity in this the 100th Anniversary year of the Gallipoli campaign in WWI. QSL in strictly eQSL.
Fred VK3DAC, the ANZAC 100 coordinator will be on air as a control station. Potential operating dates are the 8th and 9th of August, start time at 0000UTC which is 10am AEST,8am at Casey Station and operate for 2 hours, and then stop.
Doug is and experienced radio man but has had little experience in amateur radio, Patience is required
To set up a contact you can email firstname.lastname@example.org
Proposed schedule for Saturday the 9th August and Sunday 10th August the UTC times proposed are: are:
0000 to 0200
0400 to 0600
0900 to 1100
The frequencies are:
0000 to 0030 on 7.095MHz
0030 to 0130 on 14.250MHz
0130 to 0200 on 21.250MHz
0400 to 0430 on 7.095MHz
0430 to 0530 on 14.250MHz
0530 to 0600 on 21.250MHz
0900 to 1030 on 14.250MHz
1030 to 1100 on 3.585MHz