Space Weather Monitor

UPR-Río Piedras Site

Jose,John,Roberto Alejandro

Description of Project

We are working with the SID monitor. SID stands for Sudden Ionospheric Disturbance monitor. This is a project from the Stanford Solar Center. The antenna we have constructed and the SID receiver will allow us to detect Solar flares and other ionospheric disturbances.

The receiver is designed to observe a particular VLF transmission site that is located far from us. Our receiver is tuned to observe at 24.0 kHz the station NAA at Cutler, ME.

Notes on Antenna Construction and Operation by Alejandro Silva Díaz

Antenna Troubleshooting:

When we connected the antenna to the SIDMON, the voltage gave us a straight 4.991 V line. We tried to solve the problem by reducing the TNC connector to 96 feet. We also tried to reconnect the connections. Having no results, we decided to measure the resistance of the TNC and the magnetic cable. The data we got was:

The accepted resistance for the cable was from 2.5 to 10 ohms. Take a look at our "Advice at the time of building your antenna" to see what we did.

With 40 feet of cable we had left, we obtained a 3.0 ohm resistance. Small, but just enough. We succeeded in obtaining 6 turns to the frame, We obtained an initial voltage of - 2.300 V. We calibrated he SIDMON so the signal fell in the established voltage of -1.50V to -1.25V, specifically -1.40V.

Advice at time of building your antenna:

When you are building your antenna, follow all instructions on the SID manual. However, there are some tips you should be aware of, and take into consideration before taking any action:

Before wrapping your cable into your frame, make sure that it's resistance stands between 2.5 to 10 ohms. Otherwise, your antenna will pick up too much voltage, and give you a straight line at 4.96 V. Although the ideal situation would be to have 50 turns, it is more important that your antenna follows this rule. If your cable has too much resistance, you have two options:

  1. Buy a thicker cable.
  2. Cut your cable.

    In order to know how much you have to cut, you should use the equation
    R=ρ(L/A). Where R=Resistance of metal wire, ρ= constant called the resistivity that depends on what material the wire is made of, L=length of cable, A= cross sectional Area of the wire. Remember R has to equal somewhere along 2.5 and 10 ohms, and since ρ and A are constant, you can simply not take them into consideration. Thus, for example if you cut the cable in half, you divide the resistance by half.

How to take and look at your data:

We are working with a pc that runs Windows XP. Once your antenna and SIDMON are calibrated working properly, you are ready to take some data. Put your antenna in the proper position (consult the Stanford Solar Center Staff for a direction to point your antenna towards to), make sure everything is connected and open the SID Monitor Application.

Press Esc to open the Menu and D to open Datalog mode. Once you're in Datalog, you are saving data in a file. Allow a few minutes to pass by to see if you get a nice graph, and once you have it, do a test of at least 8 hours.

To look for your data, go to C:\Program Files\Solar SID\Data (Go to My Computer, C: Hard Disk, Program Files, Solar SID, Data) Inside that folder, you will see many documents in .CSV format. They open with the Notepad program, and are named after the date and time you began Datalog. (ie. 20070709_123409_NAA_S-0001 stands for 07/09/2007 at 12:38:09 (09=seconds) taken with the NAA Station and Serial Number S-0001)

To open your file, right-click the one you want to open and select "Open with", click on "Select Program" and search for a program in which you can create tables and graphs. Microsoft Office Excel will do just fine.

In our case, we used the OpenOffice.org Calc, an Excel-like program. Once you have your data, on the table, select insert table (or chart) and make sure you use a line graph. On Excel, you should use the "scattered" option.

Now you have your data, as well as your graph!

Have fun!!!

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