diff --git a/lib/PHPExif/Mapper/Exiftool.php b/lib/PHPExif/Mapper/Exiftool.php
index 70fb732..a5d1ac8 100644
--- a/lib/PHPExif/Mapper/Exiftool.php
+++ b/lib/PHPExif/Mapper/Exiftool.php
@@ -286,12 +286,13 @@ public function mapRawData(array $data) : array
                     }
                     break;
                 case self::GPSLATITUDE:
-                    $latitudeRef = !array_key_exists('GPS:GPSLatitudeRef', $data) ?
-                        'N' : $data['GPS:GPSLatitudeRef'][0];
                     $value = $this->extractGPSCoordinates($value);
                     if ($value === false) {
                         continue 2;
                     }
+                    $latitudeRef = !array_key_exists('GPS:GPSLatitudeRef', $data)
+                        || $data['GPS:GPSLatitudeRef'] === null || $data['GPS:GPSLatitudeRef'] === '' ?
+                        'N' : $data['GPS:GPSLatitudeRef'][0];
                     $value *= strtoupper($latitudeRef) === 'S' ? -1 : 1;
                     break;
                 case self::GPSLONGITUDE_QUICKTIME:
@@ -301,12 +302,13 @@ public function mapRawData(array $data) : array
                     }
                     break;
                 case self::GPSLONGITUDE:
-                    $longitudeRef = !array_key_exists('GPS:GPSLongitudeRef', $data) ?
-                        'E' : $data['GPS:GPSLongitudeRef'][0];
                     $value = $this->extractGPSCoordinates($value);
                     if ($value === false) {
                         continue 2;
                     }
+                    $longitudeRef = !array_key_exists('GPS:GPSLongitudeRef', $data)
+                        || $data['GPS:GPSLongitudeRef'] === null || $data['GPS:GPSLongitudeRef'] === '' ?
+                        'E' : $data['GPS:GPSLongitudeRef'][0];
                     $value *= strtoupper($longitudeRef) === 'W' ? -1 : 1;
                     break;
                 case self::GPSALTITUDE:
diff --git a/lib/PHPExif/Mapper/ImageMagick.php b/lib/PHPExif/Mapper/ImageMagick.php
index 109ff0f..079a685 100644
--- a/lib/PHPExif/Mapper/ImageMagick.php
+++ b/lib/PHPExif/Mapper/ImageMagick.php
@@ -184,21 +184,23 @@ public function mapRawData(array $data) : array
                     $value = preg_split('/([\s,]+)/', $value)[0];
                     break;
                 case self::GPSLATITUDE:
-                    $latitudeRef = !array_key_exists('exif:GPSLatitudeRef', $data) ?
-                        'N' : $data['exif:GPSLatitudeRef'][0];
                     $value = $this->extractGPSCoordinates($value);
                     if ($value === false) {
                         continue 2;
                     }
+                    $latitudeRef = !array_key_exists('exif:GPSLatitudeRef', $data)
+                        || $data['exif:GPSLatitudeRef'] === null || $data['exif:GPSLatitudeRef'] === '' ?
+                        'N' : $data['exif:GPSLatitudeRef'][0];
                     $value *= strtoupper($latitudeRef) === 'S' ? -1 : 1;
                     break;
                 case self::GPSLONGITUDE:
-                    $longitudeRef = !array_key_exists('exif:GPSLongitudeRef', $data) ?
-                        'E' : $data['exif:GPSLongitudeRef'][0];
                     $value  = $this->extractGPSCoordinates($value);
                     if ($value === false) {
                         continue 2;
                     }
+                    $longitudeRef = !array_key_exists('exif:GPSLongitudeRef', $data)
+                        || $data['exif:GPSLongitudeRef'] === null || $data['exif:GPSLongitudeRef'] === '' ?
+                        'E' : $data['exif:GPSLongitudeRef'][0];
                     $value *= strtoupper($longitudeRef) === 'W' ? -1 : 1;
                     break;
                 case self::GPSALTITUDE:
diff --git a/lib/PHPExif/Mapper/Native.php b/lib/PHPExif/Mapper/Native.php
index 02b52e4..9d328a1 100644
--- a/lib/PHPExif/Mapper/Native.php
+++ b/lib/PHPExif/Mapper/Native.php
@@ -235,8 +235,9 @@ public function mapRawData(array $data) : array
                     $value = (int) reset($resolutionParts);
                     break;
                 case self::GPSLATITUDE:
-                    $GPSLatitudeRef = '';
-                    if (array_key_exists('GPSLatitudeRef', $data) && $data['GPSLatitudeRef'][0] !== '') {
+                    $GPSLatitudeRef = 'N';
+                    if (array_key_exists('GPSLatitudeRef', $data)
+                        && $data['GPSLatitudeRef'] !== null && $data['GPSLatitudeRef'][0] !== '') {
                         $GPSLatitudeRef = $data['GPSLatitudeRef'][0];
                     }
                     $value = $this->extractGPSCoordinate((array)$value, $GPSLatitudeRef);
@@ -245,8 +246,9 @@ public function mapRawData(array $data) : array
                     }
                     break;
                 case self::GPSLONGITUDE:
-                    $GPSLongitudeRef = '';
-                    if (array_key_exists('GPSLongitudeRef', $data) && $data['GPSLongitudeRef'][0] !== '') {
+                    $GPSLongitudeRef = 'E';
+                    if (array_key_exists('GPSLongitudeRef', $data)
+                        && $data['GPSLongitudeRef'] !== null && $data['GPSLongitudeRef'][0] !== '') {
                         $GPSLongitudeRef = $data['GPSLongitudeRef'][0];
                     }
                     $value = $this->extractGPSCoordinate((array)$value, $GPSLongitudeRef);
@@ -255,6 +257,10 @@ public function mapRawData(array $data) : array
                     }
                     break;
                 case self::GPSALTITUDE:
+                    $value = $this->normalizeComponent($value);
+                    if ($value === false) {
+                        continue 2;
+                    }
                     $flp = 1;
                     if (array_key_exists('GPSAltitudeRef', $data) && $data['GPSAltitudeRef'][0] !== '') {
                         $flp = (
@@ -262,10 +268,6 @@ public function mapRawData(array $data) : array
                             || $data['GPSAltitudeRef'][0] === "\u{0001}"
                         ) ? -1 : 1;
                     }
-                    $value = $this->normalizeComponent($value);
-                    if ($value === false) {
-                        continue 2;
-                    }
                     $value *= $flp;
                     break;
                 case self::IMGDIRECTION:
diff --git a/tests/PHPExif/Mapper/ExiftoolMapperTest.php b/tests/PHPExif/Mapper/ExiftoolMapperTest.php
index 898cc28..1abeb05 100644
--- a/tests/PHPExif/Mapper/ExiftoolMapperTest.php
+++ b/tests/PHPExif/Mapper/ExiftoolMapperTest.php
@@ -400,6 +400,24 @@ public function testMapRawDataOnlyLatitude()
         $this->assertCount(1, $result);
     }
 
+    /**
+     * @group mapper
+     * @covers \PHPExif\Mapper\Exiftool::mapRawData
+     */
+    public function testMapRawDataCorrectlyIgnoresEmptyGPSData()
+    {
+        $result = $this->mapper->mapRawData(
+            array(
+                \PHPExif\Mapper\Exiftool::GPSLATITUDE  => '',
+                'GPS:GPSLatitudeRef'                   => '',
+                \PHPExif\Mapper\Exiftool::GPSLONGITUDE => '',
+                'GPS:GPSLongitudeRef'                  => '',
+            )
+        );
+
+        $this->assertEquals(false, reset($result));
+    }
+
     /**
      * @group mapper
      * @covers \PHPExif\Mapper\Exiftool::mapRawData
@@ -512,6 +530,21 @@ public function testMapRawDataCorrectlyNegativeAltitude()
         $this->assertEquals($expected, reset($result));
     }
 
+    /**
+     * @group mapper
+     * @covers \PHPExif\Mapper\Exiftool::mapRawData
+     */
+    public function testMapRawDataCorrectlyIgnoresIncorrectAltitude()
+    {
+        $result = $this->mapper->mapRawData(
+            array(
+                \PHPExif\Mapper\Exiftool::GPSALTITUDE  => 'undef',
+                'GPS:GPSAltitudeRef'                   => '0',
+            )
+        );
+        $this->assertEquals(false, reset($result));
+    }
+
     /**
      * @group mapper
      * @covers \PHPExif\Mapper\Exiftool::mapRawData
diff --git a/tests/PHPExif/Mapper/ImageMagickMapperTest.php b/tests/PHPExif/Mapper/ImageMagickMapperTest.php
index ce60598..9d1184f 100644
--- a/tests/PHPExif/Mapper/ImageMagickMapperTest.php
+++ b/tests/PHPExif/Mapper/ImageMagickMapperTest.php
@@ -361,9 +361,9 @@ public function testMapRawDataIncorrectlyFormatedGPSData()
         $result = $this->mapper->mapRawData(
             array(
                 \PHPExif\Mapper\ImageMagick::GPSLATITUDE  => '40/1 20/1 42857/100000',
-                'GPS:GPSLatitudeRef'                   => 'N',
+                'exif:GPSLatitudeRef'                     => 'N',
                 \PHPExif\Mapper\ImageMagick::GPSLONGITUDE => '20/1 10/1 233333/100000',
-                'GPS:GPSLongitudeRef'                  => 'W',
+                'exif:GPSLongitudeRef'                    => 'W',
             )
         );
         $this->assertCount(0, $result);
@@ -402,13 +402,31 @@ public function testMapRawDataOnlyLatitude()
         $result = $this->mapper->mapRawData(
             array(
                 \PHPExif\Mapper\ImageMagick::GPSLATITUDE => '40.333452381',
-                'GPS:GPSLatitudeRef'                  => 'North',
+                'exif:GPSLatitudeRef'                    => 'North',
             )
         );
 
         $this->assertCount(1, $result);
     }
 
+    /**
+     * @group mapper
+     * @covers \PHPExif\Mapper\ImageMagick::mapRawData
+     */
+    public function testMapRawDataCorrectlyIgnoresEmptyGPSData()
+    {
+        $result = $this->mapper->mapRawData(
+            array(
+                \PHPExif\Mapper\ImageMagick::GPSLATITUDE  => '0/0, 0/0, 0/0',
+                'exif:GPSLatitudeRef'                     => '',
+                \PHPExif\Mapper\ImageMagick::GPSLONGITUDE => '0/0, 0/0, 0/0',
+                'exif:GPSLongitudeRef'                    => '',
+            )
+        );
+
+        $this->assertEquals(false, reset($result));
+    }
+
 
     public function testMapRawDataCorrectlyFormatsDifferentDateTimeString()
     {
@@ -477,6 +495,21 @@ public function testMapRawDataCorrectlyNegativeAltitude()
         $this->assertEquals($expected, reset($result));
     }
 
+    /**
+     * @group mapper
+     * @covers \PHPExif\Mapper\ImageMagick::mapRawData
+     */
+    public function testMapRawDataCorrectlyIgnoresIncorrectAltitude()
+    {
+        $result = $this->mapper->mapRawData(
+            array(
+                \PHPExif\Mapper\ImageMagick::GPSALTITUDE  => '0/0',
+                'exif:GPSAltitudeRef'                     => '0',
+            )
+        );
+        $this->assertEquals(false, reset($result));
+    }
+
 
         /**
          * @group mapper
diff --git a/tests/PHPExif/Mapper/NativeMapperTest.php b/tests/PHPExif/Mapper/NativeMapperTest.php
index 2285c5a..a637319 100644
--- a/tests/PHPExif/Mapper/NativeMapperTest.php
+++ b/tests/PHPExif/Mapper/NativeMapperTest.php
@@ -345,6 +345,24 @@ public function testMapRawDataCorrectlyFormatsGPSData()
         }
     }
 
+    /**
+     * @group mapper
+     * @covers \PHPExif\Mapper\Native::mapRawData
+     */
+    public function testMapRawDataCorrectlyIgnoresEmptyGPSData()
+    {
+        $result = $this->mapper->mapRawData(
+            array(
+                'GPSLatitude'     => array('0/0', '0/0', '0/0'),
+                'GPSLatitudeRef'  => null,
+                'GPSLongitude'    => array('0/0', '0/0', '0/0'),
+                'GPSLongitudeRef' => null,
+            )
+        );
+
+        $this->assertEquals(false, reset($result));
+    }
+
     /**
      * @group mapper
      * @covers \PHPExif\Mapper\Native::mapRawData
@@ -368,6 +386,21 @@ public function testMapRawDataCorrectlyFormatsAltitudeData()
         }
     }
 
+    /**
+     * @group mapper
+     * @covers \PHPExif\Mapper\Native::mapRawData
+     */
+    public function testMapRawDataCorrectlyIgnoresIncorrectAltitude()
+    {
+        $result = $this->mapper->mapRawData(
+            array(
+                'GPSAltitude'     => "0/0",
+                'GPSAltitudeRef'  => chr(0),
+            )
+        );
+        $this->assertEquals(false, reset($result));
+    }
+
     public function testMapRawDataCorrectlyFormatsDifferentDateTimeString()
     {
         $rawData = array(