S
server
Guest
Even during WWII, radars were sending microsecond-wide multi-megawatt
transmit pulses. In subsequent years, radars hit the wall on transmit
power from reasonably-sized antennas. They would arc the waveguides
and plasma the air in front of the antenna. Wider pulses lost range
resolution.
So they invented chirp radar around 1965, a wide pulse that sweeps
frequency during the pulse. At receive time, it can be processed to
reconstruct a narrow pulse and restore range resolution.
I thought of this while feeding my scrub jays breakfast on the deck.
Birds chirp; must have copied the concept from radar. I suspect that a
distinct time:frequency pattern distinguishes species and improves the
detection s/n. So I have developed my own chirp whistle that the birds
can learn to recognize from a distance, when I have their morning
treats.
This morning one jay couldn\'t wait for me to distribute the treats
onto the deck (mixed Fritos and Cheetos) so landed on my fingers and
started eating out of my hand. Adorable. Then it bit my thumb for
dessert.
--
John Larkin Highland Technology, Inc
Science teaches us to doubt.
Claude Bernard
transmit pulses. In subsequent years, radars hit the wall on transmit
power from reasonably-sized antennas. They would arc the waveguides
and plasma the air in front of the antenna. Wider pulses lost range
resolution.
So they invented chirp radar around 1965, a wide pulse that sweeps
frequency during the pulse. At receive time, it can be processed to
reconstruct a narrow pulse and restore range resolution.
I thought of this while feeding my scrub jays breakfast on the deck.
Birds chirp; must have copied the concept from radar. I suspect that a
distinct time:frequency pattern distinguishes species and improves the
detection s/n. So I have developed my own chirp whistle that the birds
can learn to recognize from a distance, when I have their morning
treats.
This morning one jay couldn\'t wait for me to distribute the treats
onto the deck (mixed Fritos and Cheetos) so landed on my fingers and
started eating out of my hand. Adorable. Then it bit my thumb for
dessert.
--
John Larkin Highland Technology, Inc
Science teaches us to doubt.
Claude Bernard