diff --git a/mission/controller/acs/SensorProcessing.cpp b/mission/controller/acs/SensorProcessing.cpp
index c93c6027..5a35e8c1 100644
--- a/mission/controller/acs/SensorProcessing.cpp
+++ b/mission/controller/acs/SensorProcessing.cpp
@@ -24,19 +24,20 @@ void SensorProcessing::processMgm(const float *mgm0Value, bool mgm0valid, const
                                   bool mgm4valid, timeval timeOfMgmMeasurement,
                                   const AcsParameters::MgmHandlingParameters *mgmParameters,
                                   acsctrl::GpsDataProcessed *gpsDataProcessed,
-                                  const double gpsAltitude, bool gpsValid,
                                   acsctrl::MgmDataProcessed *mgmDataProcessed) {
   // ---------------- IGRF- 13 Implementation here
   // ------------------------------------------------
   double magIgrfModel[3] = {0.0, 0.0, 0.0};
-  if (gpsValid) {
+  bool gpsValid = false;
+  if (gpsDataProcessed->source.value != acs::GpsSource::NONE) {
     Igrf13Model igrf13;
     igrf13.schmidtNormalization();
     igrf13.updateCoeffGH(timeOfMgmMeasurement);
     // maybe put a condition here, to only update after a full day, this
     // class function has around 700 steps to perform
     igrf13.magFieldComp(gpsDataProcessed->gdLongitude.value, gpsDataProcessed->gcLatitude.value,
-                        gpsAltitude, timeOfMgmMeasurement, magIgrfModel);
+                        gpsDataProcessed->altitude.value, timeOfMgmMeasurement, magIgrfModel);
+    gpsValid = true;
   }
   if (!mgm0valid && !mgm1valid && !mgm2valid && !mgm3valid && !mgm4valid) {
     {
@@ -627,11 +628,7 @@ void SensorProcessing::process(timeval now, ACS::SensorValues *sensorValues,
              sensorValues->mgm3Rm3100Set.fieldStrengths.value,
              sensorValues->mgm3Rm3100Set.fieldStrengths.isValid(),
              sensorValues->imtqMgmSet.mtmRawNt.value, sensorValues->imtqMgmSet.mtmRawNt.isValid(),
-             now, &acsParameters->mgmHandlingParameters, gpsDataProcessed,
-             sensorValues->gpsSet.altitude.value,
-             (sensorValues->gpsSet.latitude.isValid() && sensorValues->gpsSet.longitude.isValid() &&
-              sensorValues->gpsSet.altitude.isValid()),
-             mgmDataProcessed);
+             now, &acsParameters->mgmHandlingParameters, gpsDataProcessed, mgmDataProcessed);
 
   processSus(sensorValues->susSets[0].channels.value, sensorValues->susSets[0].channels.isValid(),
              sensorValues->susSets[1].channels.value, sensorValues->susSets[1].channels.isValid(),
diff --git a/mission/controller/acs/SensorProcessing.h b/mission/controller/acs/SensorProcessing.h
index 7bd88fa2..b6b0be0c 100644
--- a/mission/controller/acs/SensorProcessing.h
+++ b/mission/controller/acs/SensorProcessing.h
@@ -31,8 +31,8 @@ class SensorProcessing {
                   const float *mgm2Value, bool mgm2valid, const float *mgm3Value, bool mgm3valid,
                   const float *mgm4Value, bool mgm4valid, timeval timeOfMgmMeasurement,
                   const AcsParameters::MgmHandlingParameters *mgmParameters,
-                  acsctrl::GpsDataProcessed *gpsDataProcessed, const double gpsAltitude,
-                  bool gpsValid, acsctrl::MgmDataProcessed *mgmDataProcessed);
+                  acsctrl::GpsDataProcessed *gpsDataProcessed,
+                  acsctrl::MgmDataProcessed *mgmDataProcessed);
 
   void processSus(const uint16_t *sus0Value, bool sus0valid, const uint16_t *sus1Value,
                   bool sus1valid, const uint16_t *sus2Value, bool sus2valid,