AM Band Antenna Array
Studying the D-Layer of the Ionosphere is difficult due to the low plasma density that tends to occur at the bottom of the Ionosphere, necessitating relatively low frequency signals in order to probe the overhead conditions. Ionosondes, the sensors typically used to probe the Ionosphere, mostly bottom out at 1MHz and, due to the need to operate across a wide bandwidth, their antennas are very insensitive at those frequencies. My goal is to build a passive collection system utilizing local MF stations (i.e. WDAO at 1.21MHz) as transmitters to collect long-term data on ionospheric conditions in the D- and bottom of the E-layer. The problem is twofold: 1) the reflection path is expected to be HIGHLY lossy so there will be a strong direct path signal and a weak reflection path signal of interest 2) the extremely low frequency of the signals necessary make miniaturizing the antenna system difficult, especially if (as expected) we will need to operate across multiple stations and frequencies over the course of the day. My current plan is to set up an array of ~5x crossed wire-wrapped ferrite loop antennas as elements in conjunction with a variable capacitor to tune.
Date and Time
Location
Hosts
Registration
- Date: 04 Oct 2024
- Time: 03:00 PM to 04:00 PM
- All times are (UTC-04:00) Eastern Time (US & Canada)
-
Add Event to Calendar
- Contact Event Hosts
-
timothy.wolfe@afit.edu
tswolfe@ieee.org
- Co-sponsored by Wright-Patt Multi-Intelligence Development Consortium (WPMDC), The DOD & DOE Communities
Speakers
Dan of AFIT
AM Band Antenna Array
Studying the D-Layer of the Ionosphere is difficult due to the low plasma density that tends to occur at the bottom of the Ionosphere, necessitating relatively low frequency signals in order to probe the overhead conditions. Ionosondes, the sensors typically used to probe the Ionosphere, mostly bottom out at 1MHz and, due to the need to operate across a wide bandwidth, their antennas are very insensitive at those frequencies. My goal is to build a passive collection system utilizing local MF stations (i.e. WDAO at 1.21MHz) as transmitters to collect long-term data on ionospheric conditions in the D- and bottom of the E-layer. The problem is twofold: 1) the reflection path is expected to be HIGHLY lossy so there will be a strong direct path signal and a weak reflection path signal of interest 2) the extremely low frequency of the signals necessary make miniaturizing the antenna system difficult, especially if (as expected) we will need to operate across multiple stations and frequencies over the course of the day. My current plan is to set up an array of ~5x crossed wire-wrapped ferrite loop antennas as elements in conjunction with a variable capacitor to tune.
Biography:
Maj Stambovsky is a 61D Physicist currently a year into an AFIT Applied Physics PhD program. He has worked extensively with RF technology, first spending five years as an Enlisted Ground Radar Maintenance technician working primarily on AN/TPN-19 systems. Following his commission in 2012 he continued work in antenna development at AFRL/RI before PCSing and working on other RF oriented projects at Ft Meade. In 2020 Maj Stambovsky graduated AFIT with a MS in Applied Physics, with research focused on M&S of GPS signal propagation through ionospheric plasma. During his time there he also published "Method for Generating a Figure of Merit for the Selection of Antennas Under Volumetric Constraint" in conjunction with Dr. Terzouli and Dr. Marhefka. Maj Stambovsky spent some time at NASIC working on overhead IR research before moving on to a Data Masked assignment. Finally in 2023 he returned to AFIT for his doctorate.
Agenda
Studying the D-Layer of the Ionosphere is difficult due to the low plasma density that tends to occur at the bottom of the Ionosphere, necessitating relatively low frequency signals in order to probe the overhead conditions. Ionosondes, the sensors typically used to probe the Ionosphere, mostly bottom out at 1MHz and, due to the need to operate across a wide bandwidth, their antennas are very insensitive at those frequencies. My goal is to build a passive collection system utilizing local MF stations (i.e. WDAO at 1.21MHz) as transmitters to collect long-term data on ionospheric conditions in the D- and bottom of the E-layer. The problem is twofold: 1) the reflection path is expected to be HIGHLY lossy so there will be a strong direct path signal and a weak reflection path signal of interest 2) the extremely low frequency of the signals necessary make miniaturizing the antenna system difficult, especially if (as expected) we will need to operate across multiple stations and frequencies over the course of the day. My current plan is to set up an array of ~5x crossed wire-wrapped ferrite loop antennas as elements in conjunction with a variable capacitor to tune.
Please pass the word & invite others.
-----------------------