True Heading from Magnetic
Convert a magnetic heading (read off the compass) into a true heading, TH = (MH + variation) mod 360°, by adding the local magnetic variation (positive East, negative West). The compass points to magnetic north, which differs from true north depending on your position on Earth — correcting this difference is essential for navigating on the nautical chart. Enter the magnetic heading and the magnetic variation.
Resultado
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Rumo verdadeiro a partir do magnético
A bússola é fiel — mas ao norte magnético, não ao geográfico. A diferença entre os dois, que varia com o lugar e o tempo, chama-se declinação magnética (ou variação). Para plotar um rumo na carta náutica é preciso converter: Rv = (Rm + declinação) módulo 360°, somando a declinação se ela é Leste (positiva) e subtraindo se Oeste (negativa). A regra do navegador é 'declinação leste, agulha à esquerda do verdadeiro'. Em alguns lugares a declinação passa de 20° — ignorá-la põe o navio léguas fora da rota. (A bordo, ainda há o desvio causado pelo ferro do próprio navio, mas aqui tratamos só da declinação.) Informe o rumo magnético e a declinação.
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.