Further to a comment (thanks Jean-Jacques!), an option has been added to GRBlocator software to enable or disable the calculation of atmospheric refraction.

GRBlocator is a new software that helps determine the visibility of a GRB at the sub-reflective point of the path between an transmitter and a station monitoring VLF signals propagation.

The site has been updated with a page dedicated to loop antenna noise levels at VLF frequencies and calculations of SNR obtained with several antennas configurations.

The SWPC (Space Weather Prediction Center) has posted on its website the following information related to GOES X-ray data measurements:

GOES-10 X-ray Data Returns
GOES-11 Xray Data LOST

February 12, 2008 -- GOES-10 data has resumed and GOES-10 has been designed the SWPC primary GOES Satellite for X-ray data.
GOES-11 Xray Data has become unavailable and is not expected to return.
GOES-11 Data Lists ended on Feb 10, 2008.
GOES-11 Data Lists have been discontinued.

The X-ray measurements shown on this site account for this change that took place on February 12, 2008.

I wish you and your loved ones a very Happy New Year!

The website has been updated with some more theoretical additions:

• a page describing the radio noise
• mathematical description and SPICE simulations of the antenna theory, applicable to air-core and ferrite-core loops

The website has been updated with the following additions:

• a page about the solar activity
• a list of VLF transmitters

The SEC (Space Environment Center) has posted on its website the following information related to GOES X-ray data measurements:

GOES-12 X-ray Lists End
November 27, 2007 -- the GOES-12 X-ray list has been discontinued because the X-ray sensor is not operating.

The X-ray measurements shown on this site account for this change that took place on November 27, 2007.

The real-time measurements are now available again! Thanks for your patience.

The SEC (Space Environment Center) has posted on its website the following information related to GOES X-ray data measurements:

GOES Primary and Secondary Satellite Change
GOES 11 Primary, GOES 10 Secondary

Due to an anomaly on the GOES 12 X-ray Sensor (XRS) no GOES 12 X-ray data
has been available at SEC since April 12, 2250 UTC. SEC has changed its
Primary and Secondary X-ray satellite designations to GOES 11 Primary and
GOES 10 Secondary.

There may be minor differences between GOES XRS sensors but the differences
should not affect products.

For now GOES X-ray data files will be created for all three GOES satellites,
GOES 11, GOES 10, and GOES 12 in case GOES 12 data is available again.

The X-ray measurements shown on this site account for this change that took place on April 12, 2007 at 22:50 UTC.

Due to a relocation of the station, the real-time data may be available for a few days or weeks during the month of April 2007. The monitoring remains full-time operational and all data measurements are archived. Sorry for the inconvenience.

On Jan 02, DHO38 has resumed transmission and signals are being received since then with a very high amplitude. The gain of the VLF receiver has been reduced to avoid overloads of the ADC converter. The change is effective at about 06:00 UTC on January, 13th 2007.

I wish you and your loved ones a very Happy New Year! Among the New Year Resolutions, one is to spend some time to finalize the version 2 of the SIDmonitor software... This version will include significant enhancements and additional functionalities, including a software multichannel VLF receiver based on the PC sound card.

The signal level of DHO38 being very low since mid of October 2006 (frequently lower than 1V at midday), I have decided to increase the gain of the VLF receiver to make a better use of the signal level ADC converter. The change is effective at about 20:00 UTC on December, 7th 2006.

A bug in the website was leading to corruption of some file downloads. It was affecting download of reports, receiver schematics and software builds. This has been fixed and download functionality should now work correctly. Do not hesitate to send me comments if you detect some more problems. Sorry for the inconvenience.

The SID monitoring station has now received the observer code A118 from the AAVSO SID Program. Data submission will start in July 2006.

Version 1.1.0 of SID Monitor is now available. It has the capability to download of GOES-11 X-ray measurements in addition to GOES-10 and GOES-12.
It also includes several bug fixes and robustness code changes in the 'Generate Report' and 'View Report' windows.

The SEC has announced Secondary GOES Spacecraft Change. Refer to SEC Info for details. GOES-10 has been replaced by GOES-11 since the 22^nd of June 06.
A new version of SID Monitor is currently under test to support update of GOES-10, 11 and 12 spacecrafts.

SID Monitoring Station web site offers now Graph and News feeds.
The News feed provides access to information and announcements related to the Station such as software updates or Web site major changes. The Graph feed provides access to a daily graph displaying the station measurements.
Both are available in Atom 1.0 and RSS 2.0 formats.