diff --git a/src/udi/handlers/ttn/models/draginoLdds75/draginoLdds75.go b/src/udi/handlers/ttn/models/draginoLdds75/draginoLdds75.go
index 351d750..1077678 100644
--- a/src/udi/handlers/ttn/models/draginoLdds75/draginoLdds75.go
+++ b/src/udi/handlers/ttn/models/draginoLdds75/draginoLdds75.go
@@ -2,6 +2,7 @@ package draginoLdds75
 
 import (
   "fmt"
+  "log"
   "strings"
   "strconv"
   "encoding/json"
@@ -25,7 +26,7 @@ type message struct {
   TempC_DS18B20 string `json:"TempC_DS18B20"`
 }
 
-func Parse(fPort int, decodedPayload []byte, variables *map[string]database.VariableType) error {
+func Parse(fPort int, decodedPayload []byte, variables *map[string]database.VariableType, device *database.Device) error {
   if fPort != 2 {
     return fmt.Errorf("Unexpected fPort %d", fPort)
   }
@@ -54,6 +55,24 @@ func Parse(fPort int, decodedPayload []byte, variables *map[string]database.Vari
     Unit: "mm",
     Value: distance,
   }
+  groundLevelI, exists := device.Attributes["GroundLevel"]
+  groundLevelS, ok := groundLevelI.(string)
+  groundLevel, err3 := strconv.Atoi(groundLevelS)
+  if exists && err3 == nil && ok {
+    log.Println("add corrected distance")
+    correctedDistance := groundLevel - distance
+    (*variables)["CorrectedDistance"] = database.VariableType {
+      Label: "CorrectedDistance",
+      Variable: "Level",
+      Unit: "mm",
+      Value: correctedDistance,
+    }
+  } else {
+    log.Printf("no ground level: %s %s %s", exists, err3, ok)
+    log.Printf("Device: %s", device)
+    log.Printf("Attributes: %s", device.Attributes)
+  }
+
   return nil
 }
 
diff --git a/src/udi/handlers/ttn/models/draginoLmds200/draginoLmds200.go b/src/udi/handlers/ttn/models/draginoLmds200/draginoLmds200.go
index cbcf4e7..ccd5c27 100644
--- a/src/udi/handlers/ttn/models/draginoLmds200/draginoLmds200.go
+++ b/src/udi/handlers/ttn/models/draginoLmds200/draginoLmds200.go
@@ -2,6 +2,7 @@ package draginoLmds200
 
 import (
   "fmt"
+  "strconv"
   "encoding/json"
   "udi/database"
 )
@@ -25,7 +26,7 @@ type message struct {
   Dis2 int `json:"dis2"`
 }
 
-func Parse(fPort int, decodedPayload []byte, variables *map[string]database.VariableType) error {
+func Parse(fPort int, decodedPayload []byte, variables *map[string]database.VariableType, device *database.Device) error {
   if fPort != 2 {
     return fmt.Errorf("Unexpected fPort %d", fPort)
   }
@@ -40,17 +41,38 @@ func Parse(fPort int, decodedPayload []byte, variables *map[string]database.Vari
     Unit: "V",
     Value: message.Bat,
   }
+  distance1 := message.Dis1 * 10
   (*variables)["Distance1"] = database.VariableType {
     Label: "Distance1",
     Variable: "Level",
     Unit: "mm",
-    Value: (message.Dis1 * 10),
+    Value: distance1,
   }
+  distance2 := message.Dis2 * 10
   (*variables)["Distance2"] = database.VariableType {
     Label: "Distance2",
     Variable: "Level",
     Unit: "mm",
-    Value: (message.Dis2 * 10),
+    Value: distance2,
+  }
+  groundLevelI, exists := device.Attributes["GroundLevel"]
+  groundLevelS, ok := groundLevelI.(string)
+  groundLevel, err3 := strconv.Atoi(groundLevelS)
+  if exists && err3 == nil && ok {
+    correctedDistance1 := groundLevel - distance1
+    (*variables)["CorrectedDistance1"] = database.VariableType {
+      Label: "CorrectedDistance1",
+      Variable: "Level",
+      Unit: "mm",
+      Value: correctedDistance1,
+    }
+    correctedDistance2 := groundLevel - distance2
+    (*variables)["CorrectedDistance2"] = database.VariableType {
+      Label: "CorrectedDistance2",
+      Variable: "Level",
+      Unit: "mm",
+      Value: correctedDistance2,
+    }
   }
   return nil
 }
diff --git a/src/udi/handlers/ttn/models/emuProfIILoRaCfg1/emuProfIILoRaCfg1.go b/src/udi/handlers/ttn/models/emuProfIILoRaCfg1/emuProfIILoRaCfg1.go
index ba88c0a..a53604b 100644
--- a/src/udi/handlers/ttn/models/emuProfIILoRaCfg1/emuProfIILoRaCfg1.go
+++ b/src/udi/handlers/ttn/models/emuProfIILoRaCfg1/emuProfIILoRaCfg1.go
@@ -177,7 +177,7 @@ type emuMessage1 struct {
 
 
 
-func Parse(fPort int, decodedPayload []byte, variables *map[string]database.VariableType) error {
+func Parse(fPort int, decodedPayload []byte, variables *map[string]database.VariableType, _ *database.Device) error {
   //log.Printf("Parse input: %d, %s", fPort, decodedPayload)
   switch fPort {
   case 1:
diff --git a/src/udi/handlers/ttn/ttn.go b/src/udi/handlers/ttn/ttn.go
index 55a93f7..f3e644c 100644
--- a/src/udi/handlers/ttn/ttn.go
+++ b/src/udi/handlers/ttn/ttn.go
@@ -142,7 +142,7 @@ func (self *TTNHandler) Handle(message handler.MessageT) {
 
   //log.Printf("DeviceLabel: %s, DeviceType: %s", device.Label, device.DeviceType.ModelIdentifier)
 
-  var parser func(int, []byte, *map[string]database.VariableType) error
+  var parser func(int, []byte, *map[string]database.VariableType, *database.Device) error
   switch device.DeviceType.ModelIdentifier {
   case "emu-prof-ii-lora-cfg1":
     parser = emuProfIILoRaCfg1.Parse
@@ -156,7 +156,7 @@ func (self *TTNHandler) Handle(message handler.MessageT) {
   }
 
   measurement.Values = make(map[string]database.VariableType)
-  err3 := parser(uplinkMessage.UplinkMessage.FPort, uplinkMessage.UplinkMessage.DecodedPayload.Payload, &(measurement.Values))
+  err3 := parser(uplinkMessage.UplinkMessage.FPort, uplinkMessage.UplinkMessage.DecodedPayload.Payload, &(measurement.Values), device)
   if err3 != nil {
     lost(fmt.Sprintf("Model parser failed: %s", err3), message)
     return