台南（北）飛行場？
Was There a Tainan North Airfield?

取自杜正宇與謝濟全著《盟軍記載的二戰臺灣機場》
Via Tu, Cheng Yu and Shieh, Chi Chuan, “Airports in Taiwan during World War II period”

上圖是美軍1944年9月的一份情報分析裡的照片，注意照片中標示了台南（北）飛行場（Tainan North Airfield），而這張照片的「原版」其實是下面這張1944年3月1日拍攝的傾斜照相：
The annotated photo above was included in a US military intelligence analysis report dated September 10, 1944. Worth noting in this oblique photo is Tainan North Airfield. But exactly where was it? I found the photo was actually based on the original (see the photo below) taken on March 1, 1944:

中央研究院海外歷史圖資與典藏 (Via Academia Sinica)

局部放大後（見下圖），可以看見被標示為台南（北）飛行場的是中央一條顏色較淺的長方形區域，另外注意在照片的左半部中間的地方還有一條顏色較深的長方形。透過照片上的地貌，就不難找出這個區域的正確位置。
The area around this “Tainan North Airfield” is shown in the enlarged version below. The so-called airfield is the rectangle in the middle. Note there is another rectangular strip, which looks a bit darker, on the left-hand side. With this image, it was not too difficult to pinpoint the location.

中央研究院海外歷史圖資與典藏 (Via Academia Sinica)

上圖涵蓋的區域大致如下面這張1921年的地圖所示（由於上面照片的北方位於右下角，所以必須把照片逆時針旋轉，才能跟以下的地圖比對），被標示為台南（北）飛行場的長方形並沒有出現在地圖上，但是它就位於圖上註明練兵場的位置。至於上圖顏色較深的長方形，原來是一座靶場（射擊場）。
In the 1921 Japanese map below, the location of the “airfield” is the drilling ground (練兵場) on the upper left-hand side. (Since the photo above was looking southwest, you would have to rotate it counterclockwise to get the same orientation as that of the map.) It turns out that the other rectangular strip in the photo above was a shooting range (射擊場).

中央研究院海外歷史圖資與典藏 (Via Academia Sinica)

美軍在1944年2月的一份情報分析用了下面這張1943年11月7日的同區域照片，不過照片上卻看不到那塊標示為機場的長方形，因此可以判定這塊長方形區域的興建日期介於1943年11月和1944年3月之間。
A February 1944 intelligence analysis report used the following photo taken on November 7, 1943. It is worth noting that the so-called Tainan North Airfield cannot be found where it is supposed to be. So it must have been built between November 1943 and March 1944.

中央研究院海外歷史圖資與典藏 (Via Academia Sinica)

美軍飛機在1944年3月1日也拍攝了這個區域的垂直照相（見下圖），我把這張照片利用Google Earth作套疊，發現所謂的台南（北）飛行場長約830公尺、寬約105公尺。雖然這樣的大小要讓二戰時期的飛機起降並非難事，卻比當時位於台灣的其他長條形飛行場要小的多，這些飛行場的長度絕大多數都在1500公尺以上，比較短的金山飛行場也有1200公尺長。因此我懷疑美軍發現的台南（北）飛行場可能是個欺敵的假機場，只是徒具飛行場的外形而已。
But was it an airfield at all? I overlaid the following March 1, 1944, vertical aerial photo on Google Earth to measure its dimension, which is about 830 x 105 m (2710 x 345 ft). Although the size was large enough for WWII-ear aircraft to take off and land, it was considerably smaller than other single-strip airfields on Formosa at that time, which normally had a runway of 1500 m (5000 ft) in length. So I suspect it was a decoy.

中央研究院海外歷史圖資與典藏 (Via Academia Sinica)

這個長條形區域在下面這張1944年8月25日的照片上就看不到了，大概是原來的地面長出了草，春夏天的草又長得快，所以外形就不見了。
Whatever it was, it was short-lived. In the following photo, taken on August 25, 1944, nothing could be found on its original location.

中央研究院海外歷史圖資與典藏 (Via Academia Sinica)

在下面這張1945年1月13日的空照裡，還是看不到原來的長方形，讓我更相信它是假機場。如果它確實是假機場，也把美國人給騙過去了（然而也只是暫時被騙而已）。
Again, nothing on the January 13, 1945, photo below. So I am more convinced that what the American analysts had found on the March 1, 1944, reconnaissance photo as “Tainan North Airfield” was in fact a decoy. And the Japanese had successfully fooled the Americans this time, albeit probably only briefly.

中央研究院海外歷史圖資與典藏 (Via Academia Sinica)

同區域的衛星照片如下。神奇的是，靶場的輪廓依然清晰可見。
The same area under the modern satellite:

By the way, the new Google Maps user interface sucks!