diff --git a/src/hello_wolf/hello_wolf.cpp b/src/hello_wolf/hello_wolf.cpp
index d3e0aa4f240f34c6d9c17ff0912783ca3131dc9b..cd14a779efb7fa38be48b1815a86d1cf09a61214 100644
--- a/src/hello_wolf/hello_wolf.cpp
+++ b/src/hello_wolf/hello_wolf.cpp
@@ -139,6 +139,7 @@ int main()
 
     // NOTE: uncomment this line below to achieve sensor self-calibration (of the orientation only, since the position is not observable)
     // sensor_rb->getOPtr()->unfix();
+    // sensor_rb->getPPtr()->unfix(); // The position is however not observable, and thus self-calibration would not work. You can try uncommenting it too.
 
     // processor Range and Bearing
     ProcessorParamsRangeBearingPtr params_rb = std::make_shared<ProcessorParamsRangeBearing>();
diff --git a/src/hello_wolf/processor_range_bearing.cpp b/src/hello_wolf/processor_range_bearing.cpp
index b2c66924f2292f30884b0d3dbebf2f31758bfbf7..5023023b603d5aa160cf84ddb5719b47550e39b2 100644
--- a/src/hello_wolf/processor_range_bearing.cpp
+++ b/src/hello_wolf/processor_range_bearing.cpp
@@ -115,11 +115,6 @@ Eigen::Vector2s ProcessorRangeBearing::observe(const Eigen::Vector2s& lmk_w) con
     return polar(toSensor(lmk_w));
 }
 
-Eigen::Vector2s ProcessorRangeBearing::invObserve(Scalar r, Scalar b) const
-{
-    return fromSensor(rect(r, b));
-}
-
 ProcessorRangeBearing::Trf ProcessorRangeBearing::transform(const Eigen::Vector3s& _pose) const
 {
     Trf H = Eigen::Translation<Scalar,2>(_pose(0), _pose(1)) * Eigen::Rotation2D<Scalar>(_pose(2)) ;
@@ -159,6 +154,11 @@ Eigen::Vector2s ProcessorRangeBearing::rect(Scalar range, Scalar bearing) const
     return range * (Vector2s() << cos(bearing), sin(bearing)).finished();
 }
 
+Eigen::Vector2s ProcessorRangeBearing::invObserve(Scalar r, Scalar b) const
+{
+    return fromSensor(rect(r, b));
+}
+
 } /* namespace wolf */