开云体育

Below is my spectrum of M101 taken with 20m Skynet radio dish at Green Bank: 10 x 1s observations, with 10 x 1s reference samples (every other observation sample) 1.5 degrees apart. Peak is at -250 km/s. This matches Wikipedia record = Heliocentric radial velocity 241 ± 2 km/s The following graph is published on ResearchGate, and comes from “An improved CESE method and its application to steady-state coronal structure simulation”, June 2013, Science China Earth Sciences 57(1). Looking at the graphs above, 250 km/s = 5-6 R (MPc) distance from ourselves on radial line of site (rlRs). From Wikipedia, Distance to M101 from Earth = 20.9 ± 1.8 Mly (6.4 ± 0.5 Mpc). So, my observations match closely to published data on velocity and distance of M101. All those astrophotographers in my astronomy club with remote observing rigs they rent ain’t seen nothing yet……I’ve got a 20m scope at Green Bank Observatory!!!! Yippee! Andy

My first observations with the 20m radio telescope at Green Bank. Andy

These LNAs are designed to pass 1420dB +/- 30MHz, and the product sheet states they produce 40dB amplification – this analysis with a NanoVNA supports that – S21 Logmag = 0.15dB + 40dB attenuation in the circuit (the gold device in series with LNA is a variable RF attenuator set to 40dB) = 40.15dB, and a reasonably flat top to the curve in the area of 1420MHz as well. …..so this Nooelec is good…..now to test the other ones I have! Andy

Hello Folks We now have 5 operational receivers in the UK Meteor radar network which can be viewed at https://ukmeteorbeacon.org/beaconclient/ . We have also made more than 48 hours of recordings of the full bandwidth data from all 5 receivers . During this period, meteor events have been occurring at a rate of about 2 per minute so there's plenty of data to work with and we will be making more recordings in the future especially around the time of major meteor showers. These data are available to download along with some contemporaneous notes and manual observations of the first hour of recording as a guide. It would be of great interest if there is anyone out there who could take this data and work out how to input it to software such as Spectrum Lab or SDR Console for analysis and display. To find out more go to the project web site at:- https://ukmeteorbeacon.org/LivestreamRecordingsList to find the recorded data along with guiding notes and description of the data and timing formats. Brian

Today's echo of the day shows examples of some of the properties you can observe from the UK Meteor Radar project live stream at https://ukmeteorbeacon.org/beaconclient/. The first echo. At the bottom of the screens was seen strongly by the Norman Lockyer receiver ( No 1, top left) and by both the NW Hampshire receivers, ( Nos 4 and 5, Bottom row) but not by the Armagh receiver (No 2). This shows that this echo was highly directional and either not strongly linearly polarised or, more likely, that it was linearly polarised but aligned equally for both vertical and horizontal antennas perhaps at about 45 degrees to both. The next very small echo was only seen by receivers 4 and 5, much more strongly with horizontal polarisation than with vertical polarisation. The next echo immediately above the last is also much stronger at the horizontally polarised antenna ( receiver 4 ) indicating that it is strongly linearly polarised. It is also directional as receiver 2, Armagh didn't “see” it. This head echo has another interesting feature, the pulsing effect. This is caused by interference patterns resulting from the ( multi wave ) length of the ionised region “moving across” the receiving antenna as the meteor travels across the sky. Other echoes are seen on the NW Hampshire Horizontally polarised display but not others due mainly to linear polarisation and directionality. Receivers 3 and 6 have been edited from this image as they are not in service. The Blairgowrie receiver No 3, is streaming data but as yet has no antenna, poor weather having delayed it's erection. Brian

What are the different types of aerials recommended for 143Mhz meteor scatter? I would like a list to add to my talk. I use a Moxon but I know there are other types Andy Sent from Outlook for Android

Terrestrial Navigation from Cosmic Radiation Jaron Samson ESTEC, European Space Agency Navigation on earth is typically performed using satellite-based systems such as GPS. However, even if GPS is widely used, it has several weaknesses. For instance, it cannot be used underwater or underground. A few years ago, the concept of underwater and underground navigation using muons has been demonstrated. This presentation will address the principles, strengths and weaknesses of navigation using muons. The Zoom link will be sent out on Thursday 6th Feb. If you are not on the distribution list and want to join please let me know. Friday 7th March 19:30 (19:30 UTC) Alex Pettit Winter Springs, Fla Project HLine3D : A Beginners Guide to Hydrogen Emission Line Microwave Radio Astronomy A student project described (https://github.com/AP-HLine-3D/HLine3D) Registration for EUCARA25 open's on Monday 3rd Feb. visit - www.eucara.org -- ??? Paul Hearn ?? paul@... ?? RA Section Director ??