Changes between Version 6 and Version 7 of Processing/atmosphericcorrection

Timestamp:

Feb 22, 2017, 1:42:50 PM (7 years ago)

Author:

mark1

Comment:

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Processing/atmosphericcorrection

@@ -35 +35 @@
 
 * Do not stand between the sun and the survey point - you will cast a shadow over the area. Ideally stand as far back as possible so as not to create erroneous reflections. 
-* Measure level, homogeneous targets of greater size (5 - 10 times) than the resolution of the remote sensing data. In most cases this is not possible (even a square metre of concrete is not perfectly homogeneous) but try and find suitable targets. For example an expanse of car park may be suitable, a field of grass, a body of deep water. Surfaces that are not level will suffer greater from erroneous reflections (see bi-directional reflectance distribution fuinction (BRDF)). Remote sensing data will suffer from adjacency effects so the larger the target the better.
+* Measure level, homogeneous targets of greater size (5 - 10 times) than the resolution of the remote sensing data. In most cases this is not possible (even a square metre of concrete is not perfectly homogeneous) but try and find suitable targets. For example an expanse of car park may be suitable, a field of grass, a body of deep water. Surfaces that are not level will suffer greater from erroneous reflections (see bi-directional reflectance distribution function (BRDF)). Remote sensing data will suffer from adjacency effects so the larger the target the better.
 * Make sure you collect more than one observation over the target to improve the measurement statistics (get as many as possible to calculate averages and standard deviations).
 * Try to measure near the centre of the targets rather than the edge where possible. For example, if you survey a car park do not observe near the boundary fence or hedge. If observing a water body remember the depth of the bottom will also affect the reflectance (e.g. the shallow boundaries will be different to the deep centre).