Doc Ewen: The Horn, HI, and Other Events in US Radio Astronomy

Slide presentation: Microwave and Millimeter Wave Applications in the 1970s and 1980s

In this slide presentation, I have selected three sensor developments during the 1970s and late 1980s that are characteristic of activities underway at that time: 1) The Buzzards Bay Bridge, Cape Cod Canal (BC)³; 2) The Eight Channel Co-boresighted Receiver System (ECCB); and 3) The Submillimeter Wave Astronomy Satellite (SWAS). (BC)³ and ECCB were important technical precursors needed to support the successful development of SWAS.

(Click on the thumbnails for larger photos and fuller explanations.)

Slide sections:

• (BC)³
• ECCB
• SWAS

Section 1: Buzzards Bay Bridge, Cape Cod Canal (BC)³

	Slide 1: Map of lift bridge area at Cape Cod Canal.
	Slide 2: Aerial photo of Cape Cod Canal lift bridge and Bourne Bridge.
	Slide 3: Lift bridge with the 544ft span in the "up" position.
	Slide 4: Lift bridge from rip rap, west side of bridge on Cape Cod side.
	Slide 5: Tower on northwest side of Canal, taken from Cape Cod Tower.
	Slide 6: The four radiometer antennas looking toward zenith.
	Slide 7: Close up look at the four parabolic antennas.
	Slide 8: Close up look at the 740 and 1420 MHz parabolas with cylinder hoods.
	Slide 9: The antennas looking out over Buzzards Bay at 45° elevation angle.
	Slide 10: Antennas looking down at an angle near nadir.
	Slide 11: Antennas fully extended off bridge and looking just below the horizon.
	Slide 12: Antennas in stow position "on - bridge".
	Slide 13: Antennas in stow position, photographed from the upper bridge structure.
	Slide 14: Antennas photographed from the top of the bridge.
	Slide 15: Antenna track during installation.
	Slide 16: Enclosure for recording and control equipment, cantilevered off east side of bridge.
	Slide 17: Aerial view of the bridge with the radiometric sensors in the operating mode.

Section 2: ECCB Horizon Imager - 30 to 110 GHz Simultaneously

	Slide 18: Introduction to Eight-Channel Co-boresighted Receiver System (ECCB).
	Slide 19: General description of the ECCB.
	Slide 20: ECCB sensor system.
	Slide 21: Cassegrain antenna with motor-driven subreflector.
	Slide 22: Sketch of Cassegrain antenna and signal path components at entrance to GOMUX.
	Slide 23: Sketch of signal paths in GOMUX from input to each of the eight receivers.
	Slide 24: Sketch of signal paths (with photo of GOMUX for reference).
	Slide 25: Close-up of components inside the GOMUX enclosure.
	Slide 26: Composite view of all quasi-optical components of the GOMUX.
	Slide 27: Close-up of components at the entrance to the GOMUX.
	Slide 28: Close-up of entrance componants from another direction.
	Slide 29: Components at the input to receivers 7 and 3.
	Slide 30: An ECCB receiver.
	Slide 31: 40-50 GHz cooled receiver functional diagram.
	Slide 32: Connector end of an ECCB receiver.
	Slide 33: Front panel of the ECCB control unit.
	Slide 34: Back panel of the ECCB control unit.

Section 3: Submillimeter Wave Astronomy Satellite (SWAS)

	Slide 35: SWAS emblem.
	Slide 36: SWAS line observation capabilities.
	Slide 37: SWAS superheterodyne receiver scheme.
	Slide 38: SWAS functional block diagram.
	Slide 39: Integration of offset Cassegrain receiver with the cooling "cones".
	Slide 40: SWAS near field antenna range.
	Slide 41: SWAS antenna patterns measured with the near field range.
	Slide 42: Launch aircraft flies north toward San Francisco with SWAS.
	Slide 43: SWAS is "go" for orbit.
	Slide 44: SWAS in orbit in space (artist's conception, Ball Aerospace).
	Slide 45: SWAS observes sources through the galaxy.
	Slide 46: Thank you to the SWAS team from John Youngblood, Militech CEO.
	Slide 47: Congratulations from Smithsonian Astrophysical Observatory to the Militech team.