Collaborate Disseminate
If you look up at the night sky in a dark enough place, with enough patience you’re almost sure to see a satellite cross the sky. It’s pretty cool to …read more Continue reading See Satellites in Broad Daylight with This Sky-Mapping Dish Antenna
Most of us will have a hazy idea of how radar works to detect aircraft by listening for reflected radio waves. And we’ll probably also know that while radar can detect aircraft, it’s not the most efficient or useful tool in the hands of an air traffic controller. Aircraft carry …read more
Continue reading Just How Do Aircraft Transponders Work Anyway?
In the radio business, getting the high ground is key to covering as much territory from as few installations as possible. Anything that has a high profile, from a big municipal water tank to a roadside billboard to a remote hilltop, will likely be bristling with antennas, and different services …read more
Continue reading Es’hail-2: Hams Get Their First Geosynchronous Repeater
In families with three kids, the middle child always seems to get the short end of the stick. The first child gets all the attention for reaching every milestone first, and the third child will forever be the baby of the family, and the middle child gets lost in-between. Something similar happened with the U.S. manned space program in the 60s. The Mercury program got massive attention when America finally got their efforts safely off the ground, and Apollo naturally seized all the attention by making good on President Kennedy’s promise to land a man on the moon.
In between …read more
Continue reading Radar in Space: The Gemini Rendezvous Radar
SpaceX just concluded 2017 by launching 10 Iridium NEXT satellites. A footnote on the launch was the “hosted payload” on board each of the satellites: a small box of equipment from Aireon. They will track every aircraft around the world in real-time, something that has been technically possible but nobody claimed they could do it economically until now.
Challenge one: avoid adding cost to aircraft. Instead of using expensive satcom or adding dedicated gear, Aireon listen to ADS-B equipment already installed as part of international air traffic control modernization. But since ADS-B was designed for aircraft-to-aircraft and aircraft-to-ground, Aireon had …read more
Continue reading Aireon Hitchhikes on Iridium to Track Airplanes
A lot of us will use satellite communications without thinking much about the satellite itself. It’s tempting to imagine that up there in orbit is a communications hub and distribution node of breathtaking complexity and ingenuity, but it might come as a surprise to some people that most communications satellites are simple transponders. They listen on one frequency band, and shift what they hear to another upon which they rebroadcast it.
This simplicity is not without weakness, for example the phenomenon of satellite hijacking has a history stretching back decades. In the 1980s for example there were stories abroad of …read more
Continue reading Accidental Satellite Hijacks Can Rebroadcast Cell Towers
We’ve all probably done it — gazed up at a passing jetliner and wondered where it was going and what adventures its passengers were embarked upon. While the latter is hard to answer, the former just got a bit easier: just ask Alexa what the plane is.
Granted, [Nick Sypteras]’s Echo Dot isn’t quite omniscient enough to know exactly what plane you’re looking at. His system benefits from the constraints offered by the window of his Boston apartment — from the video below, we’d guess somewhere in Beacon Hill or the West End — that offers a view of the …read more
We’ve all probably done it — gazed up at a passing jetliner and wondered where it was going and what adventures its passengers were embarked upon. While the latter is hard to answer, the former just got a bit easier: just ask Alexa what the plane is.
Granted, [Nick Sypteras]’s Echo Dot isn’t quite omniscient enough to know exactly what plane you’re looking at. His system benefits from the constraints offered by the window of his Boston apartment — from the video below, we’d guess somewhere in Beacon Hill or the West End — that offers a view of the …read more
