From d3498f6a05851020da876b9c2beba00a8faa5995 Mon Sep 17 00:00:00 2001
From: Luc Maisonobe <luc@orekit.org>
Date: Mon, 22 Dec 2014 11:03:35 +0100
Subject: [PATCH] Documented the LOS building process.
---
.../markdown/tutorials/direct-location.md | 28 ++++++++++---------
1 file changed, 15 insertions(+), 13 deletions(-)
diff --git a/src/site/markdown/tutorials/direct-location.md b/src/site/markdown/tutorials/direct-location.md
index 9074301d..afa85b55 100644
--- a/src/site/markdown/tutorials/direct-location.md
+++ b/src/site/markdown/tutorials/direct-location.md
@@ -46,29 +46,31 @@ For this we need the following packages
import org.apache.commons.math3.geometry.euclidean.threed.Rotation;
import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
import org.apache.commons.math3.util.FastMath;
+ import org.orekit.rugged.los.LOSBuilder;
+ import org.orekit.rugged.los.FixedRotation;
import org.orekit.rugged.los.TimeDependentLOS;
- import org.orekit.rugged.los.FixedLOS;
+
+The raw viewing direction of pixel i with respect to the instrument is defined by the vector:
-The viewing direction of pixel i with respect to the instrument is defined by the vector:
-
- Vector3D viewDir = new Vector3D(0d, i*FastMath.toRadians(20)/2000d, 1d).normalize(); //20° field of view, 2000 pixels
+ List<Vector3D> rawDirs = new ArrayList<Vector3D>();
+ for (int i = 0; i < 2000; i++) {
+ //20° field of view, 2000 pixels
+ rawDirs.add(new Vector3D(0d, i*FastMath.toRadians(20)/2000d, 1d));
+ }
The instrument is oriented 10° off nadir around the X-axis, we need to rotate the viewing
direction to obtain the line of sight in the satellite frame
- Rotation rotation = new Rotation(Vector3D.PLUS_I, FastMath.toRadians(10));
- Vector3D los = rotation.applyTo(viewDir);
+ LOSBuilder losBuilder = new LOSBuilder(rawDirs);
+ losBuilder.addTransform(new FixedRotation(new Rotation(Vector3D.PLUS_I, FastMath.toRadians(10))));
-The viewing direction is the line of sight of one pixel. In the case of a single line sensor,
-Rugged expects to receive an array of LOS. The LOS can be time dependent (useful when applying
-time-dependent corrections to the viewing angles). Here we will suppose that the viewing
-directions are constant with time. In consequence we can use the object `FixedLOS` which is
-instantiated from the viewing direction vector.
+Here we have considered that the viewing directions are constant with time, it is also possible to
+have time-dependent lines-of-sight by using other transforms. It is also possible to append several
+transforms between the raw directions and the final lines-of-sight.
- List<TimeDependentLOS> lineOfSight = new ArrayList<TimeDependentLOS>();
- lineOfSight.add(new FixedLOS(los));
+ TimeDependentLOS lineOfSight = losBuilder.build();
### Datation model
--
GitLab