diff --git a/cxx/isce3/cuda/matchtemplate/pycuampcor/cuDeramp.cu b/cxx/isce3/cuda/matchtemplate/pycuampcor/cuDeramp.cu
index cd46e7893..25be2e59f 100644
--- a/cxx/isce3/cuda/matchtemplate/pycuampcor/cuDeramp.cu
+++ b/cxx/isce3/cuda/matchtemplate/pycuampcor/cuDeramp.cu
@@ -105,8 +105,8 @@ __global__ void cuDerampMethod1_kernel(float2 *images, const int imageNX, int co
      
     for (int i = tid; i < imageSize; i += nthreads)
     { 
-        pixelIdxX = i%imageNY;
-        pixelIdxY = i/imageNY;
+        pixelIdxX = i / imageNY;
+        pixelIdxY = i % imageNY;
         float phase = pixelIdxX*phaseX + pixelIdxY*phaseY;
         float2 phase_factor = make_float2(cosf(phase), sinf(phase));
         image[i] *= phase_factor;
diff --git a/cxx/isce3/matchtemplate/pycuampcor/cuDeramp.cpp b/cxx/isce3/matchtemplate/pycuampcor/cuDeramp.cpp
index a1d015395..fa8b2482a 100644
--- a/cxx/isce3/matchtemplate/pycuampcor/cuDeramp.cpp
+++ b/cxx/isce3/matchtemplate/pycuampcor/cuDeramp.cpp
@@ -52,8 +52,8 @@ static void cuDerampMethod1_kernel(float2 *images, const int imageNX, int const
         float phaseY = atan2f(phaseDiffY.y, phaseDiffY.x);
 
         for (int i = 0; i < imageSize; i++) {
-            const int pixelIdxX = i%imageNY;
-            const int pixelIdxY = i/imageNY;
+            const int pixelIdxX = i / imageNY;
+            const int pixelIdxY = i % imageNY;
             float phase = pixelIdxX*phaseX + pixelIdxY*phaseY;
             float2 phase_factor = make_float2(cosf(phase), sinf(phase));
             image[i] *= phase_factor;
diff --git a/tests/data/ampcor/accuracy-testdata/ovs128-rho0.8/golden/correlation_peak b/tests/data/ampcor/accuracy-testdata/ovs128-rho0.8/golden/correlation_peak
index f71dbd19c..2d13833a8 100644
Binary files a/tests/data/ampcor/accuracy-testdata/ovs128-rho0.8/golden/correlation_peak and b/tests/data/ampcor/accuracy-testdata/ovs128-rho0.8/golden/correlation_peak differ
diff --git a/tests/data/ampcor/accuracy-testdata/ovs128-rho0.8/golden/dense_offsets b/tests/data/ampcor/accuracy-testdata/ovs128-rho0.8/golden/dense_offsets
index 93a7ba97f..9b1a3d0ad 100644
Binary files a/tests/data/ampcor/accuracy-testdata/ovs128-rho0.8/golden/dense_offsets and b/tests/data/ampcor/accuracy-testdata/ovs128-rho0.8/golden/dense_offsets differ