Scientific Computing

In Libreoffice Calc, to have the first two letters capitalized when the third letter is lowercase:

Tools → Autocorrect → Options → uncheck “Correct TWo INitial CApitals”

Sometimes for large number > 10000, Matlab/Octave axes ticks will appear as exponentials. Fix this to the desired number of digits by:

set(gca,'YTickLabel',sprintf('%7d|',get(gca,'YTick')))

This example is for 7 digits.

This was the first night of operations. No GPS 1 PPS timing on either station.

The data will be put in Zenodo, but is available via Google Drive, email me to access.

I found that there was no known special hotkey that will allow one to choose which device to boot when powering-up the PC.

What I found was to keep pressing Delete key upon booting, which brings you into BIOS setup. Under the Boot tab, scroll to the bottom, where you will see “force boot” choices. Click the one you want and the PC will do a one-time boot from that device.

Here’s what to check before fielding a Windows PC in a remote location.

• SSH server
• Windows Subsystem for Linux
• Windows Firewall open on SSHD port
• open Windows Firewall to pinging
• Depending on your preferences, set Windows Update to not update automatically (since this can make your PC reboot in the middle of good data-taking).

P.C. Hansen 1998. Rank-Deficient and Discrete Ill-Posed Problems. SIAM.

Data drive write caching can lead to data loss upon unplugging an external flash drive or hard drive. Inexpensive USB flash drives may write data slowly. Operating systems use RAM to cache write data, making the copy/write operation appear done while the final data writing is actually still underway. If the drive is removed before the writing is done, that file or even the whole disk can become corrupted and unreadable.

For example, a drive writing at 10 MByte / second for a 1 GByte file could take 1000 / 10 = 100 seconds, despite the file copy operation appearing done in less than 10 seconds.

On macOS or Linux, verify writing to a flash drive is completed with sync and then click the Eject icon next to the drive’s name in Finder or File Manager.

Monitor macOS or Linux file write progress with iotop.

For Windows, use the Safely Remove Hardware icon in the system tray. Monitor Windows file write progress with Task Manager or Process Explorer.

Large pixel-count or frame-count AVIs can be converted frame-by-frame to PNG. One can then use Irfanview or other common image browser to flick back and forth between movie frames.

The conversion uses ImageMagick, which calls FFmpeg.

magick -verbose CMOSvideoshorter_halfspeed.avi -type Grayscale CMOSvideo_%03d.png

Change the baud rate of the Kenwood TS-2000 over the RS-232 serial COM port locally or remotely. Faster rates are less reliable but enable quick parameter changes. 57600 has been reliable for me with the Kenwood TS-2000 for many years, but if you have high stakes operation or a noisy environment, in general slower serial speeds are more robust.

Local baud rate change

1. menu 56
2. select baud rate. Hamlib/rigctl recommends using the highest possible baud rate i.e. 57600 baud.
3. power cycle the radio.

Remote baud rate change

1. CAT EX menu item 56.

2. Read the current baud rate by sending

    EX0560000;
   

3. The radio will answer back

    EX05600004;
   

   which implies 57600 baud since the last digit is 4.

The last digit to baud is:

0: 4800
1: 9600
2: 19200
3: 38400
4: 57600

To set baud rate remotely, send the corresponding command. E.g. to set 57600 send:

EX05600004;

and turn off the TS-2000 by sending

PS0;

Now disconnect, and reconnect at the new baud rate (here, 57600) and turn the radio on by sending:

PS1;

Note: Lost communication with the TS-2000 requires a site visit. Be prepared.

collection of Bash scripts for extensive command line control of radios and rotors via Hamlib rigctld and rotctld

NOTE: if using GPredict with Hamlib, do not use -v verbose options, since the extra text output will confuse Gpredict.