From e43a2435717831e1bc60e8c14499d7380cb09afd Mon Sep 17 00:00:00 2001 From: Johannes Hofmann Date: Wed, 28 May 2008 22:13:46 +0200 Subject: add note about refraction to README --- README | 8 ++++++++ src/Panorama.cxx | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/README b/README index 85c4097..1c02e0f 100644 --- a/README +++ b/README @@ -125,6 +125,14 @@ not shown by default, but you can enable the display of hidden objects using the Option->Show Hidden menu entry. Hidden objects and hidden GPS way points are displayed in blue. +Refraction +========== + +Refraction caused by temperature and density gardients in the atmosphere is +taken into account according to the approximation described by Tom Chester in: +http://tchester.org/sgm/analysis/peaks/refraction_calculation.html +under the assumption of a temperature change of 6.5°C per 1000m and a +temperature T0 at view point level of 10°C. Stitching ========= diff --git a/src/Panorama.cxx b/src/Panorama.cxx index a072fd0..aa358ec 100644 --- a/src/Panorama.cxx +++ b/src/Panorama.cxx @@ -433,7 +433,7 @@ Panorama::alpha(const Hill *m) { double Panorama::refraction(const Hill *m) { - double a, b, c, alpha = 6.5, T0 = 0.0; + double a, b, c, alpha = 6.5, T0 = 10.0; a = 2.9e-4 * exp (-view_height / 10000.0) / (1.0 + 2.9 * T0 / 760.0); b = 2.9 * alpha / (760.0 * (1.0 + 2.9 * T0 / 760.0)); -- cgit v1.2.3