SM6FHZ 432 MHz Meteor Scatter Planning

Patience and persistence is the mother of 70cm meteor scatter!

As a newbie to 432 MHz meteor scatter I need to have a good scheme to follow when doing my planning for the best utilization of the showers. 

Objective

To find and propose a simple and efficient method for planning Meteor Scatter skeds in order to get as much out of the shower as possible with the knowledge available to us today.


Planning tool

I have implemented the equations for calculating the radiant position versus time of the meteor showers into Matlab and compiled it into a standalone application that can be used without access to Matlab. I call it RadiantCalc and it is presently in version 2.0. You can see examples of the plots generated by RadiantCalc below. Many thanks to Dr. Peter Duffett-Smith of University of Cambridge for the great assistance in understanding how to implement the equations for calculation of Sidereal Time as well as for calculating the shower peak time from the known Solar Longitude into RadiantCalc.

By downloading and running the installer you will be able to run RadiantCalc at your computer. The installer need to have Internet access in order to get the Matlab Runtime Environment and does take some time to install. Place the installation file in an folder and run it from there. For running RadiantCalc no Internet access is needed. The Matlab Runtime Environment needs a 64 bit Windows operating system. Once you have the Matlab Runtime Environment installed you can update RadiantCalc to a newer version by downloading the new executable file only. RadiantCalc does not support calculation times prior to 1582 AD, if anyone for some reason would like to do such a calculation. The algorithm used for calculating shower peak time from Solar Longitude is said to be usable from 1900 AD to 2100 AD. RadiantCalc is not intended to be used for calculations outside this time window anyway.

Download the installation file for Matlab Runtime Environment and RadiantCalc v1.53 here:

http://www.2ingandlin.se/RadiantCalc_Installer_web_v1_53.zip

and if you already have the Matlab Runtime Environment installed:

http://www.2ingandlin.se/RadiantCalc_v1_53.zip

Download the installation file for Matlab Runtime Environment and RadiantCalc v2.0 here:

http://www.2ingandlin.se/RadiantCalc_Installer_web_v2_0.zip

and if you already have the Matlab Runtime Environment installed:

http://www.2ingandlin.se/RadiantCalc_v2_0.zip

The Matlab Runtime Environment can be found here as well for installation. Use R2018a (9.4):

https://se.mathworks.com/products/compiler/matlab-runtime.html

Meteor showers

So far I have implemented Quadrantides, Lyrids, eta-Aquariids, Perseides, Draconids, Orionids, Leonids and Geminids in the tool. There is also an "Other" option where you can give the RA, Declination and Solar Longitude for the shower you would like to do calculations for.

Planning

There are a few parameters that are good to grasp when planning for meteor scatter skeds on 432 MHz. 

  1. Calculation of the predicted time for the peak of the shower for the year in question is done in RadiantCalc. The input information in RadiantCalc is taken from the Meteor Calendar found at the IMO web page. Here is a link to the Meteor Calender for 2019 (pdf-file). Use the solar longitude (lambda index Sun) under "Maximum" from the table at the end of the list. This value for Solar Longitude for 2019 is implemented in RadiantCalc as the default value. This value is used in RadiantCalc for calculating the predicted time for the shower maximum. This value is approximate and may not exactly reflect the radio maximum. If information on the radio peak is available from previous years this may be used to get a better prediction by adding about 6 hours from last years radio peak. You need to adjust back for years with a leap day.

    Meteor Shower List from IMO   

  2. Use the above retrieved data when running RadiantCalc.

    RadianCalc shower entry
    Enter the shower you want to calculate data for (Note; case sensitive) by typing the proposed short for it into the dialouge box and click on "OK" or simply click on "OK" if you want the default.

    RqdiantCalc latitude entry
    In this box you can change shower parameters that does not fit your calculation, i.e. Solar Longitude, declination or RA of the shower if you disagree on the default values. I.E. if you feel you have better information about Solar Longitude than the data in the IMO table, you can use that data for the calculation. Write a "Y" or a "y" in the next box for plotting a line in the plot showing the calculated best directions for the time you write in the lowest dialouge box.  Click "OK" when you are ready to proceed. 

    RadiantCalc shower peak hour entry
    Enter the year you would like to calculate and change month or day if you disagree with the default values for the shower in question.  If you want to include Daylight Saving Time, enter the number of hours applicable. Enter your Time Zone. Enter UTC if you would like the plot to be presented in UTC rather than in your local time. Note; "UTC" and "local" is case sensitive. Click "OK" when you are ready to proceed.

    RadiantCalc parameter change entry box
    Enter your latitude and longitude, if you do not want to use my latitude and longitude that is the default value. Click on "OK" when you are done in order to perform the calculation.

    RadiantCalc result window
    You should now see something like this, but with your entered data.


    RadiantCalc, redo calculation?
    You now get a question if you would like to do more calculations. The default value is "Y" for yes, type "N" or "n" if you want to quit.
    Click "OK" to proceed. The new plot will be a new figure number with the new data, keeping the previous plot intact. Cut the plot using the "Snipping Tool" if you like to save it for later reference. You need to exit RadiantCalc before you can use the Windows Snipping Tool.

You can follow this procedure and use this tool for planning your 432 MHz Meteor Scatter skeds and work.

Examples of radiant graphs from RadiantCalc below.

Radiant position plot for Leonids for 57 deg N  Radiant position plot as function of UTC for Leonids at 57.64 deg N

Radiant plot for Geminids at 57 deg N  Radiant position plot as function of UTC for Geminids at 57.64 deg N

Radiant position Quadrantids 57 deg N   Radiant position plot for Quadrantids at 57.64 deg N

Version 2.0 GUI

RadiantCalc 2.0 GUI

Revision history

Version 2.0:

Version 1.53:

Version 1.52:

Version 1.51:

 Version 1.5:

Resources

The International Meteor Organization web page: https://www.imo.net/

Meteor Calendar from IMO: https://www.imo.net/resources/calendar/

Live plots of meteor activity as ZHR from IMO: https://www.imo.net/members/imo_live_shower

More info on meteor scatter: https://www.rudius.net/oz2m/ms.htm 

OK1TEH info on meteor scatter: http://ok1teh.nagano.cz/ms_70cmlog_text.htm


http://www.2ingandlin.se/SM6FHZ_main.htm

Updated Februay 16, 2021.              http://www.2ingandlin.se/SM6FHZ.htm