【CASK EFFECT】0910F阅读全方位锻炼--越障【SCI】 1-11

tuziduiduiUID: 2599524

【CASK EFFECT】0910G阅读能力基础自测（速度、难度、深度、越障、真题、RAM）
https://bbs.gter.net/forum.php?mod=viewthread&tid=910464&highlight

【CASK EFFECT】0910F阅读全方位锻炼--越障【SCI】汇总贴
https://bbs.gter.net/thread-982020-1-1.html

规则：0 u, r. g$ C/ d+ [4 f5 C

我每天贴出1000字左右的一篇文字7 j) N0 Q, Q- ]( V4 E

没有别的要求，只要大家坚持读完就可以

如果你能坚持一个月，你会发现自己的阅读进化了~
[注]9 K7 C8 w4 {" L
1、直接在电脑屏幕面前做，虽然GRE阅读是在纸上考，但是这个过程会遏制你做笔记，同时给你的阅读造成视觉障碍，也就是把难度训练和抗干扰训练同步结合，增加效率（初期会很累，但是既然大家想要成为高手，那么就别对自己太温柔）

Today's topic: Technology Not Realized: Air Force Radar in the Early Pacific War


Japan's stunning employment of air power on the first day of the Pacific War, in 1941,is readily acknowledged by most; but its corollary— the failure of U.S. air power in the Philippines and Hawaii—is often overlooked. While this failure of American air power may be written off to the tactical—and operational—surprise achieved in Hawaii, this was hardly the case in the Philippines, where the U.S. Army Forces in the Far East (USAFFE) had many hours of warning. Both Hawaii and the Philippines had operational radar sets that tracked the incoming raids, yet Army Air Forces fighters failed to intercept the Japanese bombers. What went wrong? How did the technology that saved Britain in 1940 let America down?

Early U.S. Army Air Defense Concepts
The U.S. Army's involvement with the concept of area air defense can he traced to the late 1920s. In the era of small Air Corps exercises and slow First World War-era bombers, point defense of targets, such as airfields, was relatively easy. This changed in the 1930s. During exercises in Ohio in 1931, Air Corps fighter aircraft achieved little success against "enemy" bombers reported by a ground observer net. Later, Capt. Claire Chennault, an instructor at the Air Corps Tactical School, devised a warning system based on the British experience in World War I. This rudimentary air defense system, using ground observers coupled with filter centers, improved plotting techniques, and better command and control, achieved success in the Air Corps' May 1933, maneuvers.Additional exercises in the late 1930s, laid the foundation for the Army's airdefense doctrine that was in place in 1941. This system, though, was limited by its sensors—volunteer civilians spread across the countryside. America's primary air threat of the era was coming from offshore—where precious few observers lived and operated. Thankfully, technology was preparing to fill this gap with a new sensor—the radar set.

The U.S. Army and Radar
The Army's relationship with radar technology dates back to the early 1930s,through development activities at the Signal Corps Laboratories, located at Fort Monmouth, N.J. Despite concurrent experimental activity in Europe,American radar research was independent of outside influences. Though hampered by a lack of funds and personnel, a practical demonstration was possible with in a few years. On December 14-15, 1936, a successful test of the technology was conducted. This test led to the construction of a hand-built prototype, which was presented to the Chief of the Signal Corps on May 18-19, 1937, followed by a demonstration to the Secretary of War Harry Woodring a week later. The technology was well received and gave birth to a development program that led to the creation of the SCR-268 searchlight controlling radar.^ The Chief of the Air Corps Maj. Gen. Oscar Westover, who also attended the May demonstration and one on June 3, 1937, proposed an operational specification for a long-range early warning radar to meet Air Corps needs.'* Emphasis on the Air Corps requirement sent Fort Monmouth's staff back to the drawing board. By early 1939, both a mobile (soon designated SCR-270) and fixed (SCR-271) version of an early warning radar had been developed. An engineering model of the SCR-270 was tested in June 1939, and a November demonstration to the Secretary of War—involving two radars located at Twin Lights, N.J. and Meriden, Ct. was deemed a success.''' The Army established the 1st Aircraft Warning Company at Fort Monmouth on March 1,1940, and soon thereafter took delivery of the initial production SCR-270A radar sets for operational testing.

The SCR-270 Early Warning Radar
The Army adopted the SCR-270 in May 1940, and a contract for mass production was signed with Westinghouse in August.'' The SCR-270 was a long-range search radar intended to provide early warning of an approaching air raid; the SCR-270 came in many variants. The first two systems delivered were SCR-270s, followed by five improved SCR- 27OAs that incorporated minor changes to the antenna mount. The variant in production at the start of World War II was the SCR-270B, differing from its predecessor by having radar components moved fi-om the antenna mount to the operations truck. The SCR-270B was a mobile radar that required four trucks for transport; two vehicles were dedicated to moving the radar antenna, one truck to housing the generator and a fourth truck to house the transmitter, receiver,and operator position. The SCR-270B had a nominal maximum range of 150 miles as marked on the oscilloscope display at the operator position, though the Army training manual for the system noted a maximum range against bombers at 10,000feet as 80-120 miles and fighters as 50-75 miles. The radar operated within the Very High Frequency (VHF) band at 104-112 Megahertz, utilizing a 55- foot vertical broadside array antenna. " Though the antenna was placed on a tower and the transmitter and receiver were emplaced in a building, the SCR-271was essentially the same as the SCR-270 in operation.

The SCR-270B was operated by four persons. Two maintenance technicians supported the generators and electronics, while an operator worked the actual radar. The fourth man was a communication specialist who relayed targets tracked by the operator to a headquarters command post (called information centers in that era, filter centers in today's vernacular) via telephone or radio. The radar operator would manually rotate the antenna (via an antenna drive) across his assigned sector, a 360 degree scan taking about 90 seconds. Once the operator saw a return or "echo" on his five-inch "A" scope, he ceased his scan and rotated the antenna hack and forth a few degrees until he determined the azimuth that gave the largest return. The target azimuth was determined by reading three-inch high numbers painted on plates attached to the rotating antenna tower base. Measurement of range was a little more complicated. Usually only 75 miles of the radar sweep was visible on the oscilloscope; a rotating knob allowed the oscilloscope to move back and forth across the entire 150-mile range of the radar. To get the range of a radar return,the operator would use a rotating knob to move the display until the echo was lined up under a vertical line etched in the center of the screen. A range associated with the position of the now-centered echo could then he read out in a small window associated with the rotating control knob. The echo size grew with the number of aircraft, but it was not possible to identify the exact number of aircraft the radar was detecting. Finally, all radar returns were just that - raw energy reflected back from the skin of the target aircraft. The SCR-270 lacked an "identification friend or foe" or "IFF" transponder capability that enabled friendly aircraft to have a distinct response. While the Royal Air Force (RAF) had this function in their radars for the 1940 Battle of Britain, the Signal Corps was still developing an American IFF system in1941.

Another limitation with the SCR-270 was its inability to provide altitude data for targets that were being tracked. This liability was noted from the beginning by Air Corps commander Gen. Henry H. "Hap" Arnold, but there was little that could be done about it. Arnold unsuccessfully tried to acquire the SCR-268to provide altitude capability to radar sites, but these radars were already behind in their delivery schedules due to the priority assigned to SCR-270development. The Signal Corps attempted to provide an interim altitude capability with modifications to their existing radars. Engineers tried to increase the range of the SCR-268 to make it a stand-alone, three-dimensional radar capable of ground-controlled intercept; they also explored making a height finder attachment for the SCR-270. Unfortunately, both ideas were limited by the existing designs and the need to field a radar as soon as possible. While the development of the Army's first radar set was not easy, it was only half the battle. The deployment of the SCR-270 was another challenge that needed to be overcome.

On March 10, 1939, the Chief Signal Officer was instructed to prepare a comprehensive plan for the organization and operation of an Air Warning Service for the continental United States and select overseas locations. The final study was completed in February 1940, and provided for twenty-three radar sites supporting nine information centers. The first radar unit, the Signal Company,Air Warning, Panama, was formed in January 1940. In May 1940, it departed the U.S. and received two fixed-site SCR-271 radars in June. Located at Fort Sherman, Canal Zone, this building-mounted site became the first radar station in U.S. service.^^ Unfortunately for the U.S., world events limited the Army's methodical approach to fielding this new technology.

The German Blitzkrieg against Poland, in September 1939, and its employment of air power sent a shockwave around the world. In November 1939, General Arnold asked the War Department to address the nation's lack of an air defense capability for the United States. On February 26, 1940, the War Department created the Air Defense Command under Brig. Gen. James Chaney. The Air Defense Command was chartered to conduct experiments in the northeastern United States to determine tactics for the integration of fighter aircraft, anti-aircraft artillery (AAA) and radar sensors.

Later that year, Arnold sent Chaney to England to gather information about the RAF's successful defense of Britain and to develop tactics, techniques and procedures for Army Air Corps air defense operations. The Plans Division of the Air Corps took Chane/s report and other data and issued their findings on October 30, 1940.Their plan called for a British-style air defense organization for both the Continental United States (CONUS) and America's possessions in Hawaii, the Canal Zone and the Philippines. Chane/s efforts also contributed to the opening of the Air Defense School at Mitchel Field, N.Y., in March 1941. Its short course provided an overview of the RAF's summer 1940 success and provided instruction in the emerging U.S. air defense system.

In March 1941, the Army took a cue fi-om the British, whose RAF controlled the airdefense system that protected England, and transferred responsibility for thegrovmg Air Warning Service network to the General Headquarters Air Force (GHQAF).This move aligned command and control of fighters and sensors under a singlecommand.^° A lot of things were changing, doctrinally, technologically andorganizationally, as the U.S. rushed to incorporate lessons learned out ofthefirst stages of World War II.

dairymanUID: 2683905

头晕的要死，根本看不进去啊……唉，感冒真要命，sign一下，晚上看看能不能好些

icevyUID: 2552434

够牛的训练方法  实在不习惯对着电脑看  努力中

dairymanUID: 2683905

恩，今天看了一下杨鹏推荐的阅读方法，这一篇基本上两三分钟就能扫完了







但是一点都没读懂……

lghscuUID: 2552043

难道真的是Radar导致美国在Pacific War中的失利？

有时间时我得去查查相关资料

solosandraUID: 2889127

话说我居然看了10分钟 10分钟!
严重自我谴责!