Merge branch 'develop' into zipper-tiles

src/main/java/org/orekit/rugged/api/AlgorithmId.java

@@ -25,7 +25,7 @@ public enum AlgorithmId {
     /** Fast algorithm due to Bernardt Duvenhage.
      * <p>
      * The algorithm is described in the 2009 paper:
-     * <a href="http://researchspace.csir.co.za/dspace/bitstream/10204/3041/1/Duvenhage_2009.pdf">Using
+     * <a href="https://researchspace.csir.co.za/dspace/bitstream/10204/3041/1/Duvenhage_2009.pdf">Using
      * An Implicit Min/Max KD-Tree for Doing Efficient Terrain Line of Sight Calculations</a>.
      * </p>
      */
@@ -34,7 +34,7 @@ public enum AlgorithmId {
     /** Fast algorithm due to Bernardt Duvenhage.
      * <p>
      * The algorithm is described in the 2009 paper:
-     * <a href="http://researchspace.csir.co.za/dspace/bitstream/10204/3041/1/Duvenhage_2009.pdf">Using
+     * <a href="https://researchspace.csir.co.za/dspace/bitstream/10204/3041/1/Duvenhage_2009.pdf">Using
      * An Implicit Min/Max KD-Tree for Doing Efficient Terrain Line of Sight Calculations</a>.
      * </p>
      * <p>

src/main/java/org/orekit/rugged/intersection/duvenhage/DuvenhageAlgorithm.java

@@ -34,7 +34,7 @@ import org.orekit.rugged.utils.NormalizedGeodeticPoint;
 /** Digital Elevation Model intersection using Bernardt Duvenhage's algorithm.
  * <p>
  * The algorithm is described in the 2009 paper:
- * <a href="http://researchspace.csir.co.za/dspace/bitstream/10204/3041/1/Duvenhage_2009.pdf">Using
+ * <a href="https://researchspace.csir.co.za/dspace/bitstream/10204/3041/1/Duvenhage_2009.pdf">Using
  * An Implicit Min/Max KD-Tree for Doing Efficient Terrain Line of Sight Calculations</a>.
  * </p>
  * @author Luc Maisonobe

src/site/markdown/design/digital-elevation-model.md

@@ -33,7 +33,7 @@ implementations among which user can select.
 Five different algorithms are predefined in Rugged:
 
  * a recursive algorithm based on Bernardt Duvenhage's 2009 paper
-   [Using An Implicit Min/Max KD-Tree for Doing Efficient Terrain Line of Sight Calculations](http://researchspace.csir.co.za/dspace/bitstream/10204/3041/1/Duvenhage_2009.pdf)
+   [Using An Implicit Min/Max KD-Tree for Doing Efficient Terrain Line of Sight Calculations](https://researchspace.csir.co.za/dspace/bitstream/10204/3041/1/Duvenhage_2009.pdf)
  * an alternate version of the Duvenhage algorithm using flat-body hypothesis,
  * a basic scan algorithm sequentially checking all pixels in the rectangular array defined by Digital Elevation Model entry and exit points,
  * an algorithm that ignores the Digital Elevation Model and uses a constant elevation over the ellipsoid.