[1] 日本の領土やその他日本に属する領域はたくさんあります。
[4] 海しる / MSIL, , https://www.msil.go.jp/msil/htm/topwindow.html
[5] >>3 直線基線と領海外縁線の表示がありますが、 生座標データはなくタイル画像データだけです (政府標準利用規約)。
[6] 日本の陸域を大雑把に囲む多角形 (領土はすべて含み、領海も概ね含むが不正確、 200海里水域はそれなりに含む)
{"lat":35.262290171262606,"lon":129.52549541458012}, {"lat":33.63563443112933,"lon":128.11152711598143}, {"lat":27.350347623784252,"lon":122.69130149811586}, {"lat":22.818018713458926,"lon":122.42140894091759}, {"lat":21.46928247377045,"lon":125.74416177967775}, {"lat":22.451602587213536,"lon":127.43306430310153}, {"lat":19.910331362180518,"lon":132.72485690436136}, {"lat":17.550912179219264,"lon":133.21061202970304}, {"lat":16.53723722190111,"lon":138.13503721601717}, {"lat":20.22565975490805,"lon":140.48645650704304}, {"lat":24.577877843701554,"lon":146.08591144544644}, {"lat":18.180686409947512,"lon":155.28310995076697}, {"lat":23.502592722918372,"lon":160.08685089215786}, {"lat":49.547861062839964,"lon":159.3554522102241}, {"lat":56.39427546745975,"lon":144.1097173256088}, {"lat":54.936641506776475,"lon":141.51017029606572}, {"lat":52.18604106241055,"lon":141.58175707690273}, {"lat":49.968503479436386,"lon":141.37523485646417}, {"lat":45.97493268294697,"lon":140.02162914620013}, {"lat":40.57302091108701,"lon":135.0996451677164}, {"lat":39.391052033518854,"lon":131.81659632507836}, {"lat":35.721172006694296,"lon":130.9465206056198}, {"lat":35.262290171262606,"lon":129.52549541458012},
[8] >>6 から国土地理院の詳細なタイル画像がない地域を除去したもの。
{"lat":35.262290171262606,"lon":129.52549541458012}, {"lat":33.63563443112933,"lon":128.11152711598143}, {"lat":27.350347623784252,"lon":122.69130149811586}, {"lat":22.818018713458926,"lon":122.42140894091759}, {"lat":21.46928247377045,"lon":125.74416177967775}, {"lat":22.451602587213536,"lon":127.43306430310153}, {"lat":19.910331362180518,"lon":132.72485690436136}, {"lat":17.550912179219264,"lon":133.21061202970304}, {"lat":16.53723722190111,"lon":138.13503721601717}, {"lat":20.22565975490805,"lon":140.48645650704304}, {"lat":24.577877843701554,"lon":146.08591144544644}, {"lat":18.180686409947512,"lon":155.28310995076697}, {"lat":46.7195903678211,"lon":148.71198705249572}, {"lat":45.31730227791727,"lon":145.14328950844268}, {"lat":45.97493268294697,"lon":140.02162914620013}, {"lat":40.57302091108701,"lon":135.0996451677164}, {"lat":39.391052033518854,"lon":131.81659632507836}, {"lat":35.721172006694296,"lon":130.9465206056198}, {"lat":35.262290171262606,"lon":129.52549541458012},
[7] こういうもっと正確なポリゴンデータ、どっかに落ちてそうなのに探しても見つからなかった。