Who uses MBC?

Over-the-road transport (rail, truck, naval, and aircraft), government agencies (military), SNOTEL, geological / environmental / hydrological / meteorological monitoring, etc.

What kind of debris creates meteors?

Most anything! They tend to be rock or metal, and can originate from comet disintegration, asteroids, planetoid and proto-planet residue, astronomical body collisions, and a whole lot more! If this interests you, check out the wiki on meteors!

Why are your meteor counts so low as compared to other sources such as other published work and those which can be heard on livemeteors.com?

Before considering reasons for low counts, bear in mind that there are three major factors affecting the strength of a signal reflected from a meteor:

• The size of the ionized meteor trail; larger ionized trails simply reflect more signal. Extremely small and/or slower moving meteoroids produce a smaller ionized trail.
• The power provided by the illuminating transmitter. Less power from the transmitter produces less signal reflected toward the receiver for any given size of ionized trail.
• The geometry of the reflection. Meteors far from the center line of the path between transmitter and receiver tend to reflect less signal in the direction of the receiver for any given ionized trail size.

With these factors in mind, there are two main reasons for lower counts:

• Most other sites receive "pings" from meteors illuminated by a single known-location high power source such as a single distant "regional" TV station transmitter or the GRAVES space radar system in Europe. In these cases, a meteor detection station may use a very high gain directional antenna pointed directly at the source which allows for detection of meteors with a wide range of reflected signal strengths along the path, including weaker signals.
  • In KARL's case, signals are received from meteors along paths from two separate LOW power "community" TV station transmitters in opposite directions, one east and one west. It was necessary to use an antenna optimized for an omnidirectional "full sky" view in order to detect meteors along the separate paths. This type of antenna is, necessarily, low gain. The combination of low power illumination and the low gain receiving antenna means there are many meteors reflecting a signal too weak for KARL to receive.
• KARL's location, as part of a large modern metropolitan area and in close proximity to both an international airport and many satellite airports frequented by general aviation and corporate aircraft, is plagued by both terrestrial noise and "scatter" from airborne reflectors such as airplanes and helicopters, and occasional but longer lasting troposphere effects. As such, it is necessary to aggressively filter out these noise sources. A side effect of the filtering makes KARL less sensitive to weak signals thus decreasing the counts.
  • The "full sky" view of the antenna, as explained above, also contributes more noise from multiple directions. However, if instead KARL were to utilize a high gain directional antenna pointed at a single low power TV station source, there would be NO meteors detected from along the path between KARL and a second illumination source. The directional antenna would increase contributions from one source while decreasing contributions from the other; all still in the presence of high noise. This configuration would likely further reduce the counts.

Why did you use SDR v.s. a traditional analog amateur radio receiver or transceiver, and what the heck is SDR anyway?

Wikipedia says "Software-defined radio (SDR) is a radio communication system where components that have been traditionally implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system.".

The diurnal variation and duration portions of this project required ONLY receive (RX) functionality. A traditional "analog" receiver, or transceiver, capable of the required frequency range and selectivity costs somewhere in the range of $400 (used) to $1000 and its transmit (TX) functionality would have gone unused. As we anticipated the need for more sophisticated filtering and processing at the receiver, we realized that SDR features would have been helpful. Modern transceivers (TX/RX) with this capability are somewhere in the range of $800 (used) to $2000+. As data acquisition "around the clock" was necessary, this would have inefficiently "tied up" an expensive transceiver for several months using only a very tiny portion of its capabilities; RX only on a single frequency.

As SDR is considered "the future" within many radio disciplines, it is currently the subject of a great deal of experimentation throughout academia, industry, and among hobbyists. Driven by these experiments, and their common use as High Definition television receivers in most other countries, there are now a large number of very capable low cost "receive only" SDR products on the market; some available for around $30. As we were intending to acquire data over a relatively longer period, frequency stability of the receiver was very important! This forced us to consider the "higher end" products which include a very stable Temperature Controlled Crystal Oscillator (TCXO). An obvious choice here was the SDRplay RSP2 available new for $169 from several sources. As Dave had one available to lend for free, the choice was easy.

For inquiries beyond this depth, we suggest these links:

• https://en.wikipedia.org/wiki/Software-defined_radio
• http://www.radiohobbyist.org/blog/?p=390
• http://www.arrl.org/software-defined-radio .

How does KARL versioning work?

Click here!

What happened to E.T. Phone Home?

In order to sound more "science-y" for competition at CSEF and ISEF, "E.T. Phone Home" was dropped in favor of the subtitle "Diurnal Variation of Meteor Usable for Radio Communications". However, the subtitle still wasn't as clear as it could be, so it was modified to contain reference to duration, "Diurnal Variation and Duration of Meteor Usable for Radio Communications". This website will stay at etphonehome18, and nothing else will change - only the formal name.

What got you interested in this topic?

When I was preparing to take SRS, my mom invited Dave over for a dinner party thing. We were talking, and on an offhand comment, he mentioned that they use this "Meteor Burst Communication" to track shipping trucks! I was baffled, and had to know more ... and here we are!

How long did this take you?

A lot of time, from a lot of people! I personally devoted at least 3 hours a day to this project over the months I worked on it, and Dave (lead algorithm designer) has done exponentially more work than that!

When I asked you, you said you are majoring in Civil Engineering. This project has nothing to do with Civil Engineering - what gives?

I'm not really sure what I want to do with my life yet, if I'm being honest. I decided to start my college career in Civil Engineering because I've been interested in buildings since I was very young - but this project also fascinates me! Ultimately, I am deeply interested in the world around me, and am trying to see as many aspects of it as possible, with Radio Astronomy through this project being one outlet of my devotion to learning.

Where do you get your icons?

The icons on this site are the icons8 Wired collection. The icons in my presentations and on my posters were all designed by me, using Affinity Designer. My logo was also self-made using the Affinity Suite.