diff --git a/cartographer/sensor/CMakeLists.txt b/cartographer/sensor/CMakeLists.txt
index 000b0b0..18147a6 100644
--- a/cartographer/sensor/CMakeLists.txt
+++ b/cartographer/sensor/CMakeLists.txt
@@ -43,6 +43,15 @@ google_library(sensor_configuration
     transform_transform
 )
 
+google_library(sensor_data
+  HDRS
+    data.h
+  DEPENDS
+    kalman_filter_pose_tracker
+    sensor_laser
+    transform_rigid_transform
+)
+
 google_library(sensor_laser
   SRCS
     laser.cc
diff --git a/cartographer/sensor/data.h b/cartographer/sensor/data.h
new file mode 100644
index 0000000..44084bf
--- /dev/null
+++ b/cartographer/sensor/data.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2016 The Cartographer Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CARTOGRAPHER_MAPPING_DATA_H_
+#define CARTOGRAPHER_MAPPING_DATA_H_
+
+#include <string>
+
+#include "cartographer/kalman_filter/pose_tracker.h"
+#include "cartographer/sensor/laser.h"
+#include "cartographer/transform/rigid_transform.h"
+
+namespace cartographer {
+namespace sensor {
+
+// This type is a logical union, i.e. only one type of sensor data is actually
+// filled in. It is only used for time ordering sensor data before passing it
+// on.
+struct Data {
+  enum class Type { kImu, kLaserFan3D, kOdometry };
+
+  struct Odometry {
+    transform::Rigid3d pose;
+    kalman_filter::PoseCovariance covariance;
+  };
+
+  struct Imu {
+    Eigen::Vector3d linear_acceleration;
+    Eigen::Vector3d angular_velocity;
+  };
+
+  Data(const string& frame_id, const Imu& imu)
+      : type(Type::kImu), frame_id(frame_id), imu(imu) {}
+
+  Data(const string& frame_id,
+       const ::cartographer::sensor::LaserFan3D& laser_fan_3d)
+      : type(Type::kLaserFan3D),
+        frame_id(frame_id),
+        laser_fan_3d(laser_fan_3d) {}
+
+  Data(const string& frame_id, const Odometry& odometry)
+      : type(Type::kOdometry), frame_id(frame_id), odometry(odometry) {}
+
+  Type type;
+  string frame_id;
+  Imu imu;
+  sensor::LaserFan3D laser_fan_3d;
+  Odometry odometry;
+};
+
+}  // namespace sensor
+}  // namespace cartographer
+
+#endif  // CARTOGRAPHER_MAPPING_DATA_H_