diff --git a/test/aprsme/encoding_test.exs b/test/aprsme/encoding_test.exs
index d231b52..d14271b 100644
--- a/test/aprsme/encoding_test.exs
+++ b/test/aprsme/encoding_test.exs
@@ -83,4 +83,90 @@ defmodule Aprsme.EncodingTest do
       assert result == "Café"
     end
   end
+
+  describe "to_float_safe/1" do
+    test "parses valid numeric string" do
+      assert Encoding.to_float_safe("3.14") == {:ok, 3.14}
+      assert Encoding.to_float_safe("42") == {:ok, 42.0}
+    end
+
+    test "trims whitespace" do
+      assert Encoding.to_float_safe("  3.14  ") == {:ok, 3.14}
+    end
+
+    test "truncates strings longer than 30 characters" do
+      # "1.0" padded with trailing zeros — valid after truncation
+      long = "1." <> String.duplicate("0", 40)
+      assert Encoding.to_float_safe(long) == {:ok, 1.0}
+    end
+
+    test "returns nil for out-of-range float" do
+      assert is_nil(Encoding.to_float_safe("9.1e15"))
+      assert is_nil(Encoding.to_float_safe("-9.1e15"))
+    end
+
+    test "returns value for in-range float" do
+      assert {:ok, f} = Encoding.to_float_safe("1000000.0")
+      assert f == 1_000_000.0
+    end
+
+    test "returns nil for invalid string" do
+      assert is_nil(Encoding.to_float_safe("abc"))
+      assert is_nil(Encoding.to_float_safe(""))
+    end
+
+    test "returns nil for non-binary input" do
+      assert is_nil(Encoding.to_float_safe(nil))
+      assert is_nil(Encoding.to_float_safe(123))
+      assert is_nil(Encoding.to_float_safe(:atom))
+    end
+
+    test "handles scientific notation" do
+      assert {:ok, f} = Encoding.to_float_safe("1.5e3")
+      assert f == 1500.0
+    end
+
+    test "handles zero" do
+      assert Encoding.to_float_safe("0") == {:ok, 0.0}
+      assert Encoding.to_float_safe("0.0") == {:ok, 0.0}
+    end
+  end
+
+  describe "has_weather_data/4" do
+    test "returns true when single field present" do
+      assert Encoding.has_weather_data(72.0, nil, nil, nil)
+      assert Encoding.has_weather_data(nil, 50, nil, nil)
+      assert Encoding.has_weather_data(nil, nil, 5.0, nil)
+      assert Encoding.has_weather_data(nil, nil, nil, 1013.25)
+    end
+
+    test "returns true when multiple fields present" do
+      assert Encoding.has_weather_data(72.0, 50, 5.0, 1013.25)
+    end
+
+    test "returns false when all nil" do
+      refute Encoding.has_weather_data(nil, nil, nil, nil)
+    end
+
+    test "treats zero as valid weather data" do
+      assert Encoding.has_weather_data(0, nil, nil, nil)
+      assert Encoding.has_weather_data(nil, 0, nil, nil)
+    end
+
+    test "treats negative values as valid weather data" do
+      assert Encoding.has_weather_data(-10, nil, nil, nil)
+    end
+  end
+
+  describe "to_hex/1" do
+    test "returns empty string for non-binary" do
+      assert Encoding.to_hex(nil) == ""
+      assert Encoding.to_hex(123) == ""
+    end
+
+    test "handles boundary byte values" do
+      assert Encoding.to_hex(<<0>>) == "00"
+      assert Encoding.to_hex(<<255>>) == "FF"
+    end
+  end
 end
diff --git a/test/aprsme/encoding_utils_test.exs b/test/aprsme/encoding_utils_test.exs
index 3b980cd..ecb47f5 100644
--- a/test/aprsme/encoding_utils_test.exs
+++ b/test/aprsme/encoding_utils_test.exs
@@ -1,6 +1,7 @@
 defmodule Aprsme.EncodingUtilsTest do
   use ExUnit.Case
 
+  alias Aprs.Types.MicE
   alias Aprsme.EncodingUtils
   alias Aprsme.Packet
 
@@ -121,7 +122,7 @@ defmodule Aprsme.EncodingUtilsTest do
 
     test "sanitizes message field in MicE struct" do
       invalid_message = <<72, 101, 108, 108, 111, 211, 87, 111, 114, 108, 100>>
-      mic_e = %Aprs.Types.MicE{message: invalid_message, lat_degrees: 40}
+      mic_e = %MicE{message: invalid_message, lat_degrees: 40}
 
       sanitized = EncodingUtils.sanitize_data_extended(mic_e)
 
@@ -149,6 +150,194 @@ defmodule Aprsme.EncodingUtilsTest do
     end
   end
 
+  describe "to_float/1" do
+    test "converts integer to float" do
+      assert EncodingUtils.to_float(1) == 1.0
+      assert EncodingUtils.to_float(0) == 0.0
+      assert EncodingUtils.to_float(-42) == -42.0
+    end
+
+    test "returns float unchanged" do
+      assert EncodingUtils.to_float(1.5) == 1.5
+      assert EncodingUtils.to_float(-3.14) == -3.14
+      assert EncodingUtils.to_float(0.0) == 0.0
+    end
+
+    test "returns nil for out-of-range integer" do
+      assert is_nil(EncodingUtils.to_float(10_000_000_000_000_000))
+      assert is_nil(EncodingUtils.to_float(-10_000_000_000_000_000))
+    end
+
+    test "converts valid string to float" do
+      assert EncodingUtils.to_float("2.3") == 2.3
+      assert EncodingUtils.to_float("42") == 42.0
+      assert EncodingUtils.to_float("-7.5") == -7.5
+      assert EncodingUtils.to_float("0") == 0.0
+    end
+
+    test "handles string with trailing text" do
+      assert EncodingUtils.to_float("12.5abc") == 12.5
+    end
+
+    test "returns nil for invalid string" do
+      assert is_nil(EncodingUtils.to_float("bad"))
+      assert is_nil(EncodingUtils.to_float(""))
+    end
+
+    test "converts Decimal to float" do
+      assert EncodingUtils.to_float(Decimal.new("3.14")) == 3.14
+    end
+
+    test "returns nil for nil" do
+      assert is_nil(EncodingUtils.to_float(nil))
+    end
+
+    test "returns nil for unsupported types" do
+      assert is_nil(EncodingUtils.to_float(:atom))
+      assert is_nil(EncodingUtils.to_float([1, 2]))
+      assert is_nil(EncodingUtils.to_float(%{a: 1}))
+    end
+  end
+
+  describe "to_decimal/1" do
+    test "returns Decimal unchanged" do
+      d = Decimal.new("3.14")
+      assert EncodingUtils.to_decimal(d) == d
+    end
+
+    test "converts float to Decimal" do
+      result = EncodingUtils.to_decimal(1.5)
+      assert is_struct(result, Decimal)
+      assert Decimal.to_float(result) == 1.5
+    end
+
+    test "converts integer to Decimal" do
+      result = EncodingUtils.to_decimal(42)
+      assert is_struct(result, Decimal)
+      assert Decimal.equal?(result, Decimal.new(42))
+    end
+
+    test "converts valid string to Decimal" do
+      result = EncodingUtils.to_decimal("2.3")
+      assert is_struct(result, Decimal)
+      assert Decimal.equal?(result, Decimal.new("2.3"))
+    end
+
+    test "returns nil for invalid string" do
+      assert is_nil(EncodingUtils.to_decimal("bad"))
+      assert is_nil(EncodingUtils.to_decimal(""))
+    end
+
+    test "handles negative values" do
+      result = EncodingUtils.to_decimal("-7.5")
+      assert is_struct(result, Decimal)
+      assert Decimal.negative?(result)
+    end
+
+    test "handles zero" do
+      result = EncodingUtils.to_decimal(0)
+      assert Decimal.equal?(result, Decimal.new(0))
+    end
+
+    test "handles very large integer" do
+      result = EncodingUtils.to_decimal(999_999_999_999)
+      assert is_struct(result, Decimal)
+      assert Decimal.equal?(result, Decimal.new(999_999_999_999))
+    end
+
+    test "returns nil for unsupported types" do
+      assert is_nil(EncodingUtils.to_decimal(nil))
+      assert is_nil(EncodingUtils.to_decimal(:atom))
+      assert is_nil(EncodingUtils.to_decimal([1, 2]))
+    end
+  end
+
+  describe "normalize_data_type/1" do
+    test "converts atom value with atom key" do
+      assert EncodingUtils.normalize_data_type(%{data_type: :weather}) == %{data_type: "weather"}
+    end
+
+    test "converts atom value with string key" do
+      assert EncodingUtils.normalize_data_type(%{"data_type" => :position}) == %{"data_type" => "position"}
+    end
+
+    test "leaves string value unchanged" do
+      assert EncodingUtils.normalize_data_type(%{data_type: "bar"}) == %{data_type: "bar"}
+      assert EncodingUtils.normalize_data_type(%{"data_type" => "baz"}) == %{"data_type" => "baz"}
+    end
+
+    test "returns map without data_type unchanged" do
+      assert EncodingUtils.normalize_data_type(%{foo: 1}) == %{foo: 1}
+    end
+
+    test "returns non-map input unchanged" do
+      assert EncodingUtils.normalize_data_type("string") == "string"
+      assert EncodingUtils.normalize_data_type(nil) == nil
+    end
+  end
+
+  describe "weather_fields/0" do
+    test "returns all 10 weather fields" do
+      fields = EncodingUtils.weather_fields()
+      assert length(fields) == 10
+    end
+
+    test "includes expected fields" do
+      fields = EncodingUtils.weather_fields()
+      assert :temperature in fields
+      assert :humidity in fields
+      assert :wind_speed in fields
+      assert :wind_direction in fields
+      assert :wind_gust in fields
+      assert :pressure in fields
+      assert :rain_1h in fields
+      assert :rain_24h in fields
+      assert :rain_since_midnight in fields
+      assert :snow in fields
+    end
+
+    test "all fields are atoms" do
+      assert Enum.all?(EncodingUtils.weather_fields(), &is_atom/1)
+    end
+  end
+
+  describe "sanitize_packet_strings/1" do
+    test "passes DateTime through unchanged" do
+      dt = ~U[2024-01-01 00:00:00Z]
+      assert EncodingUtils.sanitize_packet_strings(dt) == dt
+    end
+
+    test "passes NaiveDateTime through unchanged" do
+      ndt = ~N[2024-01-01 00:00:00]
+      assert EncodingUtils.sanitize_packet_strings(ndt) == ndt
+    end
+
+    test "sanitizes nested map values" do
+      input = %{"outer" => %{"inner" => <<0, 65, 66>>}}
+      result = EncodingUtils.sanitize_packet_strings(input)
+      assert result["outer"]["inner"] == "AB"
+    end
+
+    test "sanitizes list elements" do
+      input = ["abc", <<0, 65, 66, 67>>]
+      result = EncodingUtils.sanitize_packet_strings(input)
+      assert result == ["abc", "ABC"]
+    end
+
+    test "converts struct to map and sanitizes" do
+      input = %MicE{message: <<0, 72, 73>>}
+      result = EncodingUtils.sanitize_packet_strings(input)
+      assert is_map(result)
+      assert result[:message] == "HI"
+    end
+
+    test "passes non-binary values through" do
+      assert EncodingUtils.sanitize_packet_strings(nil) == nil
+      assert EncodingUtils.sanitize_packet_strings(42) == 42
+      assert EncodingUtils.sanitize_packet_strings(true) == true
+    end
+  end
+
   describe "encoding_info/1" do
     test "returns info for valid UTF-8 string" do
       info = EncodingUtils.encoding_info("Hello")
diff --git a/test/aprsme/packet_geometry_test.exs b/test/aprsme/packet_geometry_test.exs
new file mode 100644
index 0000000..08a1560
--- /dev/null
+++ b/test/aprsme/packet_geometry_test.exs
@@ -0,0 +1,109 @@
+defmodule Aprsme.PacketGeometryTest do
+  use Aprsme.DataCase, async: true
+
+  alias Aprsme.Packet
+
+  describe "create_point/2" do
+    test "creates point from valid float coordinates" do
+      point = Packet.create_point(40.7128, -74.006)
+      assert %Geo.Point{coordinates: {-74.006, 40.7128}, srid: 4326} = point
+    end
+
+    test "creates point from Decimal coordinates" do
+      lat = Decimal.new("40.7128")
+      lon = Decimal.new("-74.006")
+      point = Packet.create_point(lat, lon)
+      assert %Geo.Point{srid: 4326} = point
+    end
+
+    test "creates point from integer coordinates" do
+      point = Packet.create_point(40, -74)
+      assert %Geo.Point{coordinates: {-74, 40}, srid: 4326} = point
+    end
+
+    test "returns nil for invalid latitude" do
+      assert is_nil(Packet.create_point(91.0, 0.0))
+      assert is_nil(Packet.create_point(-91.0, 0.0))
+    end
+
+    test "returns nil for invalid longitude" do
+      assert is_nil(Packet.create_point(0.0, 181.0))
+      assert is_nil(Packet.create_point(0.0, -181.0))
+    end
+
+    test "returns nil for nil coordinates" do
+      assert is_nil(Packet.create_point(nil, nil))
+      assert is_nil(Packet.create_point(40.0, nil))
+      assert is_nil(Packet.create_point(nil, -74.0))
+    end
+
+    test "handles boundary coordinates" do
+      # North pole
+      assert %Geo.Point{} = Packet.create_point(90.0, 0.0)
+      # South pole
+      assert %Geo.Point{} = Packet.create_point(-90.0, 0.0)
+      # Date line
+      assert %Geo.Point{} = Packet.create_point(0.0, 180.0)
+      assert %Geo.Point{} = Packet.create_point(0.0, -180.0)
+      # Equator/prime meridian
+      point = Packet.create_point(0.0, 0.0)
+      assert %Geo.Point{srid: 4326} = point
+      assert point.coordinates == {0.0, 0.0}
+    end
+
+    test "returns nil for non-numeric types" do
+      assert is_nil(Packet.create_point("40.0", "-74.0"))
+      assert is_nil(Packet.create_point(:lat, :lon))
+    end
+  end
+
+  describe "extract_coordinates/1" do
+    test "extracts lat/lon from Geo.Point" do
+      point = %Geo.Point{coordinates: {-74.006, 40.7128}, srid: 4326}
+      assert {40.7128, -74.006} = Packet.extract_coordinates(point)
+    end
+
+    test "returns nil tuple for nil" do
+      assert {nil, nil} = Packet.extract_coordinates(nil)
+    end
+
+    test "returns nil tuple for non-point input" do
+      assert {nil, nil} = Packet.extract_coordinates(%{lat: 40.0, lon: -74.0})
+      assert {nil, nil} = Packet.extract_coordinates("not a point")
+    end
+  end
+
+  describe "lat/1" do
+    test "returns latitude from packet with location" do
+      packet = %Packet{location: %Geo.Point{coordinates: {-74.006, 40.7128}, srid: 4326}}
+      assert Packet.lat(packet) == 40.7128
+    end
+
+    test "returns nil for packet without location" do
+      packet = %Packet{location: nil}
+      assert is_nil(Packet.lat(packet))
+    end
+
+    test "returns nil for non-packet" do
+      assert is_nil(Packet.lat(nil))
+      assert is_nil(Packet.lat(%{}))
+    end
+  end
+
+  describe "lon/1" do
+    test "returns longitude from packet with location" do
+      packet = %Packet{location: %Geo.Point{coordinates: {-74.006, 40.7128}, srid: 4326}}
+      assert Packet.lon(packet) == -74.006
+    end
+
+    test "returns nil for packet without location" do
+      packet = %Packet{location: nil}
+      assert is_nil(Packet.lon(packet))
+    end
+
+    test "returns nil for non-packet" do
+      assert is_nil(Packet.lon(nil))
+      assert is_nil(Packet.lon(%{}))
+    end
+  end
+end
diff --git a/test/aprsme/packet_test.exs b/test/aprsme/packet_test.exs
index 3f8b358..aebdf54 100644
--- a/test/aprsme/packet_test.exs
+++ b/test/aprsme/packet_test.exs
@@ -352,4 +352,210 @@ defmodule Aprsme.PacketTest do
       assert is_nil(result[:comment])
     end
   end
+
+  describe "PHG extraction" do
+    test "extracts PHG from comment string" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "PHG5530 Some comment",
+          latitude: 33.0,
+          longitude: -96.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+
+      # PHG5530: power=5^2=25, height=10*2^5=320, gain=3, dir=0*45=0
+      assert result.data["phg_power"] == 25
+      assert result.data["phg_height"] == 320
+      assert result.data["phg_gain"] == 3
+      assert result.data["phg_directivity"] == 0
+    end
+
+    test "calculates omnidirectional antenna (digit 9 = 360 degrees)" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "PHG2369 My station",
+          latitude: 40.0,
+          longitude: -74.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+
+      # PHG2369: power=2^2=4, height=10*2^3=80, gain=6, dir=9→360
+      assert result.data["phg_power"] == 4
+      assert result.data["phg_height"] == 80
+      assert result.data["phg_gain"] == 6
+      assert result.data["phg_directivity"] == 360
+    end
+
+    test "calculates directional antenna" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "PHG1064 Directional",
+          latitude: 35.0,
+          longitude: -80.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+
+      # PHG1064: power=1^2=1, height=10*2^0=10, gain=6, dir=4*45=180
+      assert result.data["phg_power"] == 1
+      assert result.data["phg_height"] == 10
+      assert result.data["phg_gain"] == 6
+      assert result.data["phg_directivity"] == 180
+    end
+
+    test "extracts PHG from data_extended map" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "My station",
+          latitude: 33.0,
+          longitude: -96.0,
+          phg: %{power: 25, height: 320, gain: 3, directivity: 0}
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+
+      assert result.data["phg_power"] == 25
+      assert result.data["phg_height"] == 320
+      assert result.data["phg_gain"] == 3
+      assert result.data["phg_directivity"] == 0
+    end
+
+    test "extracts PHG from data_extended string format" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "My station",
+          latitude: 33.0,
+          longitude: -96.0,
+          phg: "5530"
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+
+      assert result.data["phg_power"] == 25
+      assert result.data["phg_height"] == 320
+      assert result.data["phg_gain"] == 3
+      assert result.data["phg_directivity"] == 0
+    end
+
+    test "handles zero PHG values" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "PHG0000 Minimal",
+          latitude: 33.0,
+          longitude: -96.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+
+      # PHG0000: power=0^2=0, height=10*2^0=10, gain=0, dir=0*45=0
+      assert result.data["phg_power"] == 0
+      assert result.data["phg_height"] == 10
+      assert result.data["phg_gain"] == 0
+      assert result.data["phg_directivity"] == 0
+    end
+  end
+
+  describe "altitude extraction" do
+    test "extracts standard altitude from comment" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "Some info /A=001234 more info",
+          latitude: 33.0,
+          longitude: -96.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+
+      assert result[:altitude] == 1234.0
+    end
+
+    test "extracts altitude from data_extended map" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "My station",
+          latitude: 33.0,
+          longitude: -96.0,
+          altitude: 5280.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+
+      assert result[:altitude] == 5280.0
+    end
+
+    test "extracts zero altitude" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "/A=000000 ground level",
+          latitude: 33.0,
+          longitude: -96.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+
+      assert result[:altitude] == 0.0
+    end
+
+    test "returns nil when no altitude present" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "Just a plain comment",
+          latitude: 33.0,
+          longitude: -96.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+
+      assert is_nil(result[:altitude])
+    end
+
+    test "prefers data_extended altitude over comment-extracted altitude" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "/A=001000 info",
+          latitude: 33.0,
+          longitude: -96.0,
+          altitude: 9999.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+
+      assert result[:altitude] == 9999.0
+    end
+  end
 end