FORMA 是以 MODIS 為基礎的森林砍伐示警系統,適用於潮濕的熱帶森林。FORMA 的設計宗旨是快速找出樹木覆蓋面積減少的新區域。這套系統會分析 MODIS 感應器每天收集的資料,該感應器在 NASA 的 Terra 和 Aqua 衛星上運作。FORMA 警報系統會偵測植被覆蓋率的顯著變化 (以常態化差異植被指數 (NDVI) 測量),植被覆蓋率的顯著變化可能表示森林遭到砍伐、焚燒或落葉。只要將像素值設為偵測到變更的日期,系統就會在資料集中新增快訊。只有在樹木覆蓋損失機率大於或等於 50% 的區域,才會顯示 FORMA 快訊。FORMA 資料的空間解析度為 500 公尺,更新間隔為每月兩次。FORMA 警報將於 2006 年 1 月開始發布。
[[["容易理解","easyToUnderstand","thumb-up"],["確實解決了我的問題","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["缺少我需要的資訊","missingTheInformationINeed","thumb-down"],["過於複雜/步驟過多","tooComplicatedTooManySteps","thumb-down"],["過時","outOfDate","thumb-down"],["翻譯問題","translationIssue","thumb-down"],["示例/程式碼問題","samplesCodeIssue","thumb-down"],["其他","otherDown","thumb-down"]],[],[],["FORMA, a MODIS-based system, identifies new tree cover loss in humid tropical forests by analyzing daily data from NASA's Terra and Aqua satellites. It uses the Normalized Difference Vegetation Index (NDVI) to detect changes indicative of clearing, burning, or defoliation. Alerts, represented by pixel values set to the change detection date, appear where tree cover loss probability is ≥50%. The data, updated twice-monthly, has a 500-meter spatial resolution and covers January 2006 to June 2015. This data is now deprecated.\n"]]