Project Diana
Encyclopedia
Roman mythology
Roman mythology is the body of traditional stories pertaining to ancient Rome's legendary origins and religious system, as represented in the literature and visual arts of the Romans...
moon goddess Diana
Diana (mythology)
In Roman mythology, Diana was the goddess of the hunt and moon and birthing, being associated with wild animals and woodland, and having the power to talk to and control animals. She was equated with the Greek goddess Artemis, though she had an independent origin in Italy...
— goddess of the hunt, wild animals and the moon — was a project of the US Army Signal Corps to bounce radio signals off the moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
and receive the reflected signals. Today called EME
EME (communications)
Earth-Moon-Earth, also known as moon bounce, is a radio communications technique which relies on the propagation of radio waves from an Earth-based transmitter directed via reflection from the surface of the Moon back to an Earth-based receiver....
(Earth-Moon-Earth), this was the first attempt to "touch" another celestial body
Celestial Body
Celestial Body is a Croatian film directed by Lukas Nola. It was released in 2000....
.
From a laboratory at Camp Evans
Camp Evans
Camp Evans, New Jersey is a former military base associated with Fort Monmouth. It is located in Wall Township, although it is often said to be located in Belmar . The property overlooks the Shark River.Camp Evans is named after Lt. Col...
(part of Fort Monmouth
Fort Monmouth
Fort Monmouth was an installation of the Department of the Army in Monmouth County, New Jersey. The post is surrounded by the communities of Eatontown, Tinton Falls and Oceanport, New Jersey, and is located about 5 miles from the Atlantic Ocean. The post covers nearly of land, from the Shrewsbury...
), near Wall Township
Wall Township, New Jersey
Wall Township is a township in Monmouth County, New Jersey, United States. As of the 2010 United States Census, the township population was 26,164.Wall Township was formally incorporated as a township by an act of the New Jersey Legislature on March 7, 1851...
, New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
, a large transmitter
Transmitter
In electronics and telecommunications a transmitter or radio transmitter is an electronic device which, with the aid of an antenna, produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating...
, receiver
Receiver (radio)
A radio receiver converts signals from a radio antenna to a usable form. It uses electronic filters to separate a wanted radio frequency signal from all other signals, the electronic amplifier increases the level suitable for further processing, and finally recovers the desired information through...
and antenna array
Antenna array
Antenna array may refer to:*Antenna array a group of isotropic radiators such that the currents running through them are of different amplitudes and phases*Interferometric array of radio telescopes used in radio astronomy...
were constructed for this purpose. The transmitter, a highly modified SCR-271 radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
set from World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, provided 3,000 watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
s at 111.5 MHz in 1/4 second pulses, and the antenna (a "bedspring" dipole
Dipole
In physics, there are several kinds of dipoles:*An electric dipole is a separation of positive and negative charges. The simplest example of this is a pair of electric charges of equal magnitude but opposite sign, separated by some distance. A permanent electric dipole is called an electret.*A...
array) provided 24 dB
Decibel
The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...
of gain. Reflected signals were received about 2.5 seconds later, with the receiver compensating for Doppler
Doppler effect
The Doppler effect , named after Austrian physicist Christian Doppler who proposed it in 1842 in Prague, is the change in frequency of a wave for an observer moving relative to the source of the wave. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from...
modulation
Modulation
In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...
of the reflected signal. The antenna could be rotated in azimuth only, so the attempt could be made only as the moon passed through the 15 degree wide beam at moonrise and moonset, as the antenna's elevation
Elevation
The elevation of a geographic location is its height above a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface ....
angle was horizontal. About 40 minutes of observation was available on each pass as the moon transited the various lobes of the antenna pattern.
The first successful echo detection came on 10 January 1946 at 11:58am local time by John H. DeWitt and his chief scientist E. King Stodola
Edwin King Stodola
Edwin King Stodola was an American electrical engineer.He was born in Brooklyn, New York, and graduated from Cooper Union with a B.S. in Electrical Engineering in 1936, then an E.E. degree in 1947. In 1936, he worked...
.
Project Diana marked the birth of the US space program, as well as that of radar astronomy
Radar astronomy
Radar astronomy is a technique of observing nearby astronomical objects by reflecting microwaves off target objects and analyzing the echoes. This research has been conducted for six decades. Radar astronomy differs from radio astronomy in that the latter is a passive observation and the former an...
. It was the first demonstration that artificially-created signals could penetrate the ionosphere
Ionosphere
The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...
, opening the possibility of radio communications beyond the earth for space probes and human explorers. It also established the practice of naming space projects after Roman gods, e.g., Mercury
Mercury (mythology)
Mercury was a messenger who wore winged sandals, and a god of trade, the son of Maia Maiestas and Jupiter in Roman mythology. His name is related to the Latin word merx , mercari , and merces...
and Apollo
Apollo
Apollo is one of the most important and complex of the Olympian deities in Greek and Roman mythology...
.
Today, the Project Diana site is maintained by the Ocean-Monmouth
Ocean Township, Monmouth County, New Jersey
Ocean Township is a township located in east central Monmouth County, New Jersey. As of the 2010 United States Census, the township population was 27,291.Oakhurst and Wanamassa Ocean Township is a township located in east central Monmouth County, New Jersey. As of the 2010 United States Census,...
Amateur Radio Club, as part of the Infoage Science/History Learning Center
Infoage Science/History Learning Center
The Infoage Science/History Learning Center is a science center founded by Fred Carl that is located on the grounds of the former Camp Evans military base in Wall Township, New Jersey, approximately 30 miles from New York City, USA. Camp Evans is listed on the National Register of Historic Places...
.