diff -r c5d8bd1a7728 -r 6316d68b58af src/forward_model/sensor_grid.rs
--- a/src/forward_model/sensor_grid.rs	Thu Jan 23 23:35:28 2025 +0100
+++ b/src/forward_model/sensor_grid.rs	Thu Jan 23 23:34:05 2025 +0100
@@ -94,7 +94,8 @@
       S : Sensor<F, N>,
       P : Spread<F, N>,
       Convolution<S, P> : Spread<F, N>,
-      BT : SensorGridBT<F, S, P, N>, {
+      BT : SensorGridBT<F, S, P, N>,
+{
     domain : Cube<F, N>,
     sensor_count : [usize; N],
     sensor : S,
@@ -109,7 +110,7 @@
       S : Sensor<F, N>,
       P : Spread<F, N>,
       Convolution<S, P> : Spread<F, N> + LocalAnalysis<F, BT::Agg, N>,
-      /*ShiftedSensor<F, S, P, N> : LocalAnalysis<F, BT::Agg, N>*/ {
+{
 
     /// Create a new sensor grid.
     ///
@@ -148,7 +149,8 @@
       BT : SensorGridBT<F, S, P, N>,
       S : Sensor<F, N>,
       P : Spread<F, N>,
-      Convolution<S, P> : Spread<F, N> {
+      Convolution<S, P> : Spread<F, N>
+{
       
     /// Return the grid of sensor locations.
     pub fn grid(&self) -> LinGrid<F, N> {
@@ -190,7 +192,6 @@
     S : Sensor<F, N>,
     P : Spread<F, N>,
     Convolution<S, P> : Spread<F, N>,
-    //ShiftedSensor<F, S, P, N> : LocalAnalysis<F, BT::Agg, N>,
 {
 
     type Codomain =  DVector<F>;
@@ -211,7 +212,6 @@
     S : Sensor<F, N>,
     P : Spread<F, N>,
     Convolution<S, P> : Spread<F, N>,
-    //ShiftedSensor<F, S, P, N> : LocalAnalysis<F, BT::Agg, N>
 { }
 
 
@@ -222,7 +222,6 @@
       S : Sensor<F, N>,
       P : Spread<F, N>,
       Convolution<S, P> : Spread<F, N>,
-      //ShiftedSensor<F, S, P, N> : LocalAnalysis<F, BT::Agg, N>
 {
 
     fn gemv<I : Instance<RNDM<F, N>>>(
@@ -268,8 +267,8 @@
       BT : SensorGridBT<F, S, P, N, Agg=Bounds<F>>,
       S : Sensor<F, N>,
       P : Spread<F, N>,
-      Convolution<S, P> : Spread<F, N>,
-      ShiftedSensor<F, S, P, N> : LocalAnalysis<F, BT::Agg, N> {
+      Convolution<S, P> : Spread<F, N> + LocalAnalysis<F, BT::Agg, N>
+{
 
     /// An estimate on the operator norm in $𝕃(ℳ(Ω); ℝ^n)$ with $ℳ(Ω)$ equipped
     /// with the Radon norm, and $ℝ^n$ with the Euclidean norm.
@@ -278,11 +277,14 @@
         // |Aμ|_2 = sup_{|z|_2 ≤ 1} ⟨z,Αμ⟩ = sup_{|z|_2 ≤ 1} ⟨A^*z|μ⟩
         // ≤ sup_{|z|_2 ≤ 1} |A^*z|_∞ |μ|_ℳ
         // = sup_{|z|_2 ≤ 1} |∑ φ(· - x_i)z_i|_∞ |μ|_ℳ
-        // ≤ sup_{|z|_2 ≤ 1} |φ|_∞ ∑ |z_i| |μ|_ℳ
-        // ≤ sup_{|z|_2 ≤ 1} |φ|_∞ √n |z|_2 |μ|_ℳ
-        // = |φ|_∞ √n |μ|_ℳ.
+        // ≤ sup_{|z|_2 ≤ 1} |φ(y)| ∑_{i:th sensor active at y}|z_i| |μ|_ℳ
+        //      where the supremum of |∑ φ(· - x_i)z_i|_∞  is reached at y
+        // ≤ sup_{|z|_2 ≤ 1} |φ|_∞ √N_ψ |z|_2 |μ|_ℳ
+        //      where N_ψ is the maximum number of sensors that overlap, and
+        //      |z|_2 is restricted to the active sensors.
+        // = |φ|_∞ √N_ψ |μ|_ℳ.
         // Hence
-        let n = F::cast_from(self.n_sensors());
+        let n = self.max_overlapping();
         self.base_sensor.bounds().uniform() * n.sqrt()
     }
 }
@@ -297,9 +299,8 @@
       BT : SensorGridBT<F, S, P, N>,
       S : Sensor<F, N>,
       P : Spread<F, N>,
-      Convolution<S, P> : Spread<F, N> + LocalAnalysis<F, BT::Agg, N>,
-      /*ShiftedSensor<F, S, P, N> : LocalAnalysis<F, BT::Agg, N>,
-      Weighted<ShiftedSensor<F, S, P, N>, F> : LocalAnalysis<F, BT::Agg, N>*/ {
+      Convolution<S, P> : Spread<F, N> + LocalAnalysis<F, BT::Agg, N>
+{
     type PreadjointCodomain = BTFN<F, SensorGridSupportGenerator<F, S, P, N>, BT, N>;
     type Preadjoint<'a> = SensorGridPreadjoint<'a, Self, F, N> where Self : 'a;
 
@@ -317,8 +318,7 @@
       P : Spread<F, N>,
       Convolution<S, P> : Spread<F, N> + Lipschitz<L2, FloatType=F> + DifferentiableMapping<Loc<F,N>> + LocalAnalysis<F, BT::Agg, N>,
       for<'b> <Convolution<S, P> as DifferentiableMapping<Loc<F,N>>>::Differential<'b> : Lipschitz<L2, FloatType=F>,
-      /*ShiftedSensor<F, S, P, N> : LocalAnalysis<F, BT::Agg, N>,
-      Weighted<ShiftedSensor<F, S, P, N>, F> : LocalAnalysis<F, BT::Agg, N>*/ {
+{
     
     type FloatType = F;
 
@@ -345,7 +345,8 @@
 pub struct SensorGridSupportGenerator<F, S, P, const N : usize>
 where F : Float,
       S : Sensor<F, N>,
-      P : Spread<F, N> {
+      P : Spread<F, N>
+{
     base_sensor : Convolution<S, P>,
     grid : LinGrid<F, N>,
     weights : DVector<F>
@@ -355,7 +356,8 @@
 where F : Float,
       S : Sensor<F, N>,
       P : Spread<F, N>,
-      Convolution<S, P> : Spread<F, N> {
+      Convolution<S, P> : Spread<F, N>
+{
 
     #[inline]
     fn construct_sensor(&self, id : usize, w : F) -> Weighted<ShiftedSensor<F, S, P, N>, F> {
@@ -375,7 +377,8 @@
 where F : Float,
       S : Sensor<F, N>,
       P : Spread<F, N>,
-      Convolution<S, P> : Spread<F, N> {
+      Convolution<S, P> : Spread<F, N>
+{
     type Id = usize;
     type SupportType = Weighted<ShiftedSensor<F, S, P, N>, F>;
     type AllDataIter<'a> = MapX<'a, Zip<RangeFrom<usize>,
@@ -407,8 +410,7 @@
       S : Sensor<F, N>,
       P : Spread<F, N>,
       Convolution<S, P> : Spread<F, N> + LocalAnalysis<F, BT::Agg, N>,
-      /*ShiftedSensor<F, S, P, N> : LocalAnalysis<F, BT::Agg, N>,
-      Weighted<ShiftedSensor<F, S, P, N>, F> : LocalAnalysis<F, BT::Agg, N>*/ {
+{
     type Observable = DVector<F>;
 
     fn write_observable(&self, b : &Self::Observable, prefix : String) -> DynError {
@@ -428,9 +430,8 @@
       BT : SensorGridBT<F, S, P, N>,
       S : Sensor<F, N>,
       P : Spread<F, N>,
-      Convolution<S, P> : Spread<F, N> + LocalAnalysis<F, BT::Agg, N>,
-      /*ShiftedSensor<F, S, P, N> : LocalAnalysis<F, BT::Agg, N>,
-      Weighted<ShiftedSensor<F, S, P, N>, F> : LocalAnalysis<F, BT::Agg, N>*/ {
+      Convolution<S, P> : Spread<F, N> + LocalAnalysis<F, BT::Agg, N>
+{
 
     fn findim_quadratic_model(
         &self,
@@ -465,7 +466,8 @@
       P : Spread<F, N>,
       Convolution<S, P> : Spread<F, N>,
       K : SimpleConvolutionKernel<F, N>,
-      AutoConvolution<P> : BoundedBy<F, K> {
+      AutoConvolution<P> : BoundedBy<F, K>
+{
 
     type FloatType = F;
 
@@ -496,7 +498,8 @@
       BT : SensorGridBT<F, S, P, N>,
       S : Sensor<F, N>,
       P : Spread<F, N>,
-      Convolution<S, P> : Spread<F, N> + Lipschitz<L2, FloatType = F> {
+      Convolution<S, P> : Spread<F, N> + Lipschitz<L2, FloatType = F>
+{
     type FloatType = F;
 
     fn transport_lipschitz_factor(&self, L2Squared : L2Squared) -> Self::FloatType {
@@ -604,8 +607,7 @@
       S : Sensor<F, N>,
       P : Spread<F, N>,
       Convolution<S, P> : Spread<F, N> + LocalAnalysis<F, Bounds<F>, N>,
-      //ShiftedSensor<F, S, P, N> : LocalAnalysis<F, BT::Agg, N>,
-      /*Weighted<ShiftedSensor<F, S, P, N>, F> : LocalAnalysis<F, BT::Agg, N>*/ {
+{
 
     type Codomain = SensorGridBTFN<F, S, P, BT, N>;
 
@@ -627,8 +629,4 @@
       S : Sensor<F, N>,
       P : Spread<F, N>,
       Convolution<S, P> : Spread<F, N> + LocalAnalysis<F, Bounds<F>, N>,
-      /*ShiftedSensor<F, S, P, N> : LocalAnalysis<F, BT::Agg, N>,
-      Weighted<ShiftedSensor<F, S, P, N>, F> : LocalAnalysis<F, BT::Agg, N>*/ {
-
-}
-
+{ }