From dfa39ca77145ad968675ac6e25257acd518e26bb Mon Sep 17 00:00:00 2001
From: Ian Beswick <scribeopus@live.co.uk>
Date: Mon, 5 Jun 2023 16:59:55 +0100
Subject: [PATCH] Additional DF18 Airborne position data.

---
 .../java/aero/t2s/modes/decoder/df/DF18.java     | 16 ++++++++++++++++
 .../df/df17/data/SurfaceOperationalMode.java     |  2 +-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/main/java/aero/t2s/modes/decoder/df/DF18.java b/src/main/java/aero/t2s/modes/decoder/df/DF18.java
index 28293e8..60c766d 100644
--- a/src/main/java/aero/t2s/modes/decoder/df/DF18.java
+++ b/src/main/java/aero/t2s/modes/decoder/df/DF18.java
@@ -15,6 +15,22 @@ public DF18 decode() {
         int typeCode = data[4] >>> 3;
 
         switch (typeCode) {
+            case 0:
+            case 9:
+            case 10:
+            case 11:
+            case 12:
+            case 13:
+            case 14:
+            case 15:
+            case 16:
+            case 17:
+            case 18:
+            case 20:
+            case 21:
+            case 22:
+                extendedSquitter = new AirbornePosition(data, getIcao());
+                break;
             case 1:
             case 2:
             case 3:
diff --git a/src/main/java/aero/t2s/modes/decoder/df/df17/data/SurfaceOperationalMode.java b/src/main/java/aero/t2s/modes/decoder/df/df17/data/SurfaceOperationalMode.java
index b775c51..8508fe0 100644
--- a/src/main/java/aero/t2s/modes/decoder/df/df17/data/SurfaceOperationalMode.java
+++ b/src/main/java/aero/t2s/modes/decoder/df/df17/data/SurfaceOperationalMode.java
@@ -27,7 +27,7 @@ public SurfaceOperationalMode(int data) {
         acasRA = (data & 0b0010000000000000) != 0 ? AcasState.RA_ACTIVE : AcasState.RA_NOT_ACTIVE;
         acasIdent = (data & 0b0001000000000000) != 0;
         singleAntennaFlag = (data & 0b0000010000000000) != 0;
-        systemDesignAssurance = SourceIntegrityLevel.from((data & 0b0000001100000000) >>> 7);
+        systemDesignAssurance = SourceIntegrityLevel.from((data & 0b0000001100000000) >>> 8);
         int gpsAntennaOffset = (data & 0b0000000011111111);
 
         gpsLateralOffset = (gpsAntennaOffset & 0b11100000) >>> 5;