Posts Tagged ‘weak-signal’
While many are talking about how Solar Cycle 24 is the weakest since the Maunder Minimum (the period starting in about 1645 and continuing to about 1715 when sunspots became exceedingly rare, as noted by solar observers of the time — see this Wiki entry), there are moments when activity on the Sun strongly increases, providing brief moments of excitement.
Here is a case in point, witnessed by the Solar Dynamics Observatory (SDO; see SDO Mission) on June 7, 2011, when the Sun unleashed a magnitude M2 (a medium-sized) solar flare with a spectacular coronal mass ejection (CME). The large cloud of particles mushroomed up and fell back down looking as if it covered an area almost half the solar surface.
SDO observed the flare’s peak at 1:41 AM ET. SDO recorded these images in extreme ultraviolet light that show a very large eruption of cool gas. It is somewhat unique because at many places in the eruption there seems to be even cooler material — at temperatures less than 80,000 K.
This video uses the full-resolution 4096 x 4096 pixel images at a one minute time cadence to provide the highest quality, finest detail version possible. The color is artificial, as the actual images are capturing Extreme Ultraviolet light.
It is interesting to compare the event in different wavelengths because they each see different temperatures of plasma.
Credit: NASA SDO / Goddard Space Flight Center
Video: http://g.nw7us.us/1aOjmgA – Massive Solar Eruption Close-up (2011-06-07 – NASA SDO)
Ubuntu 10.10 – Maverick Meerkat
Russ upgraded from 10.04 to 10.10, which isn’t particularly easy. as 10.04 is the long-term-support (LTS) version, but 10.10 isn’t.
There is a command line command to upgrade:
which will work, but you must first make a change in the Ubuntu software center. Click Edit -> Software Sources -> Updates tab. At the bottom of the Updates tab, there are three options for the release upgrade: Never, Long-term Support Only, and Normal Releases. You must select “Normal Releases”. Russ then issued the do-release-upgrade command. Once the downloads were complete, the upgrade just took about 45 minutes. A reboot is necessary due to the newer kernel.
The desktop background is a bit different, but otherwise it looks and runs much the same as 10.04. Russ had some performance issues with 10.04 on some of his machines. He thinks 10.10 runs much better.
- GNOME updated to current 2.32 version.
- Gnome desktop manager (gdm) version 3. Russ thinks it looks more like OS-X.
- Evolution updated to version 2.30. Russ thinks they should drop Evolution entirely. There would be room for GIMP if Evolution were deleted.
- Shotwell replaces F-Spot as the default photo manager. F-Spot replaced GIMP in a previous release due to space issues, and now Shotwell replaces that. Isn’t this kind of silly?
- Gwibber updated to use Twitter’s new authentication scheme.
- More updates to KDE.
- Updates to Qt, and KDE (4.5.1).
- Switched to PulseAudio. Russ says: BOOOOO!, because he’s unhappy with all audio systems on Linux.
Ubuntu Server changes:
- Eucalyptus updated for cloud computing environments.
- 2.6.35-22.33 Based on 184.108.40.206 upstream stable kernel.
- Support for i586 and older processors, and i686 processors without the conditional move opcode (CMOV), has been dropped. Bad news for older machines.
WSPR was highlighted in the November, 2010 issue of QST.
- What is WSPR? From the WSPR Users Guide:WSPR (pronounced “whisper”) stands for “Weak Signal Propagation Reporter.” The WSPR software is designed for probing potential radio propagation paths using low-power beacon-like transmissions. WSPR signals convey a callsign, Maidenhead grid locator, and power level using a compressed data format with strong forward error correction and narrow-band 4-FSK modulation. The protocol is effective at signal-to-noise ratios as low as –28 dB in a 2500 Hz bandwidth. Receiving stations with internet access may automatically upload reception reports to a central database. The WSPRnet web site http://wsprnet.org/drupal/ provides a simple user interface for querying the database, a mapping facility, and many other features.
- Developed by Joe Taylor, K1JT.
- System Requirements:
- SSB receiver or transceiver and antenna.
- Computer running the Windows, Linux, FreeBSD, or OS X operating system.
- 1.5 GHz or faster CPU and at least 100 MB of available RAM.
- Monitor with at least 800 x 600 resolution.
- Sound card supported by your operating system and capable of 48 kHz sample rate.
- If you will transmit as well as receive, an interface using a serial port to key your PTT line or a serial cable for CAT control. Linux and FreeBSD versions can also use a parallel port for PTT. Alternatively, you can use VOX control.
- Audio connection(s) between receiver/transceiver and sound card.
- A means for synchronizing your computer clock to UTC.
- Yaesu FT-897D Transceiver.
- G5RV Antenna.
- Rascal GLX sound card interface.
- Ubuntu 9.10.
- 3 gigs of memory and an Intel 3.0 Ghz CPU.
- Onboard sound card.
- Richard downloaded what looked like the .deb package from the web site.
- He used Gdebi to unpack and install it, but could not get it to stay running. Every time he tried to do anything it crashed.
- After reading the Linux installation instructions from the user guide, he attempted to install it in the manner described:
- Download the appropriate file from http://physics.princeton.edu/pulsar/K1JT/wspr.html, place it in your home directory, and run the following commands in a terminal
$ sudo dpkg --instdir=. -i wspr_2.00r1714_i386.deb $ cd WSPR $ ./wspr
- This resulted in a program that would receive after some fooling around with the sound card, but no rig control, and no transmit.
- As a last resort, Richard downloaded the Windows version and loaded it under Wine, which gave him rig control, transmit, and receive, without much of a problem.
- It did leave him with a few minor annoyances: he has to start it from the file manager with “Open with Wine” from the directory “.wine/Drive_c/Program Files/WSPR”. The menu bar at the top was only partially functional, but he thinks it has to do with his USB mouse, as keyboard control works fine.
- Richard was heard in Argentina on 40m running 5 watts and reported on the wsprnet site.
- WSPRNet website
- WSPR net offers a wide variety of information on the network in real time.
- Page of stations currently active on WSPR.
- Map of stations that can be filtered by callsign and/or band.
- Offers dicussion forums for Q and A, setting up schedules, and general WSPR discussion.
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