diff --git a/schainpy/__init__.py b/schainpy/__init__.py
index ce6e1df..6b50397 100644
--- a/schainpy/__init__.py
+++ b/schainpy/__init__.py
@@ -5,4 +5,4 @@ try:
 except:
     pass
 
-__version__ = '3.0.0b5'
+__version__ = '3.0.0b6'
diff --git a/schainpy/model/proc/jroproc_spectra.py b/schainpy/model/proc/jroproc_spectra.py
index db44b3d..fde1262 100644
--- a/schainpy/model/proc/jroproc_spectra.py
+++ b/schainpy/model/proc/jroproc_spectra.py
@@ -873,4 +873,26 @@ class IncohInt(Operation):
             dataOut.utctime = avgdatatime
             dataOut.flagNoData = False
 
-        return dataOut
\ No newline at end of file
+        return dataOut
+
+class dopplerFlip(Operation):
+       
+    def run(self, dataOut):
+        # arreglo 1: (num_chan, num_profiles, num_heights)
+        self.dataOut = dataOut 
+        # JULIA-oblicua, indice 2
+        # arreglo 2: (num_profiles, num_heights)
+        jspectra = self.dataOut.data_spc[2]
+        jspectra_tmp = numpy.zeros(jspectra.shape)
+        num_profiles = jspectra.shape[0]
+        freq_dc = int(num_profiles / 2)
+        # Flip con for
+        for j in range(num_profiles):
+            jspectra_tmp[num_profiles-j-1]= jspectra[j]
+        # Intercambio perfil de DC con perfil inmediato anterior
+        jspectra_tmp[freq_dc-1]= jspectra[freq_dc-1]
+        jspectra_tmp[freq_dc]= jspectra[freq_dc]
+        # canal modificado es re-escrito en el arreglo de canales
+        self.dataOut.data_spc[2] = jspectra_tmp
+
+        return self.dataOut
\ No newline at end of file
diff --git a/schainpy/model/proc/jroproc_voltage.py b/schainpy/model/proc/jroproc_voltage.py
index 7a62196..9c71e4d 100644
--- a/schainpy/model/proc/jroproc_voltage.py
+++ b/schainpy/model/proc/jroproc_voltage.py
@@ -146,7 +146,7 @@ class selectChannels(Operation):
 
 class selectHeights(Operation):
 
-    def run(self, dataOut, minHei=None, maxHei=None):
+    def run(self, dataOut, minHei=None, maxHei=None, minIndex=None, maxIndex=None):
         """
         Selecciona un bloque de datos en base a un grupo de valores de alturas segun el rango
         minHei <= height <= maxHei
@@ -164,34 +164,30 @@ class selectHeights(Operation):
 
         self.dataOut = dataOut
 
-        if minHei == None:
-            minHei = self.dataOut.heightList[0]
+        if minHei and maxHei:
 
-        if maxHei == None:
-            maxHei = self.dataOut.heightList[-1]
+            if (minHei < self.dataOut.heightList[0]):
+                minHei = self.dataOut.heightList[0]
 
-        if (minHei < self.dataOut.heightList[0]):
-            minHei = self.dataOut.heightList[0]
+            if (maxHei > self.dataOut.heightList[-1]):
+                maxHei = self.dataOut.heightList[-1]
 
-        if (maxHei > self.dataOut.heightList[-1]):
-            maxHei = self.dataOut.heightList[-1]
-
-        minIndex = 0
-        maxIndex = 0
-        heights = self.dataOut.heightList
+            minIndex = 0
+            maxIndex = 0
+            heights = self.dataOut.heightList
 
-        inda = numpy.where(heights >= minHei)
-        indb = numpy.where(heights <= maxHei)
+            inda = numpy.where(heights >= minHei)
+            indb = numpy.where(heights <= maxHei)
 
-        try:
-            minIndex = inda[0][0]
-        except:
-            minIndex = 0
+            try:
+                minIndex = inda[0][0]
+            except:
+                minIndex = 0
 
-        try:
-            maxIndex = indb[0][-1]
-        except:
-            maxIndex = len(heights)
+            try:
+                maxIndex = indb[0][-1]
+            except:
+                maxIndex = len(heights)
 
         self.selectHeightsByIndex(minIndex, maxIndex)