diff --git a/cartographer/sensor/odometry_data.cc b/cartographer/sensor/odometry_data.cc
new file mode 100644
index 0000000..50b5027
--- /dev/null
+++ b/cartographer/sensor/odometry_data.cc
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2017 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.
+ */
+
+#include "cartographer/sensor/odometry_data.h"
+
+#include "cartographer/transform/transform.h"
+
+namespace cartographer {
+namespace sensor {
+
+proto::OdometryData ToProto(const OdometryData& odometry_data) {
+  proto::OdometryData proto;
+  proto.set_timestamp(common::ToUniversal(odometry_data.time));
+  *proto.mutable_pose() = transform::ToProto(odometry_data.pose);
+  return proto;
+}
+
+OdometryData FromProto(const proto::OdometryData& proto) {
+  return OdometryData{common::FromUniversal(proto.timestamp()),
+                      transform::ToRigid3(proto.pose())};
+}
+
+}  // namespace sensor
+}  // namespace cartographer
diff --git a/cartographer/sensor/odometry_data.h b/cartographer/sensor/odometry_data.h
new file mode 100644
index 0000000..c4f0778
--- /dev/null
+++ b/cartographer/sensor/odometry_data.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2017 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_SENSOR_ODOMETRY_DATA_H_
+#define CARTOGRAPHER_SENSOR_ODOMETRY_DATA_H_
+
+#include "cartographer/common/time.h"
+#include "cartographer/sensor/proto/sensor.pb.h"
+#include "cartographer/transform/rigid_transform.h"
+
+namespace cartographer {
+namespace sensor {
+
+struct OdometryData {
+  common::Time time;
+  transform::Rigid3d pose;
+};
+
+// Converts 'odometry_data' to a proto::OdometryData.
+proto::OdometryData ToProto(const OdometryData& odometry_data);
+
+// Converts 'proto' to an OdometryData.
+OdometryData FromProto(const proto::OdometryData& proto);
+
+}  // namespace sensor
+}  // namespace cartographer
+
+#endif  // CARTOGRAPHER_SENSOR_ODOMETRY_DATA_H_
diff --git a/cartographer/sensor/proto/sensor.proto b/cartographer/sensor/proto/sensor.proto
index 92ea0ba..842d681 100644
--- a/cartographer/sensor/proto/sensor.proto
+++ b/cartographer/sensor/proto/sensor.proto
@@ -20,22 +20,28 @@ option java_outer_classname = "Sensor";
 
 import "cartographer/transform/proto/transform.proto";
 
-// Compressed collection of 3D 'points'.
+// Compressed collection of a 3D point cloud.
 message CompressedPointCloud {
   optional int32 num_points = 1;
   repeated int32 point_data = 3 [packed = true];
 }
 
-// Proto representation of ::cartographer::sensor::ImuData
+// Proto representation of ::cartographer::sensor::ImuData.
 message ImuData {
   optional int64 timestamp = 1;
   optional transform.proto.Vector3d linear_acceleration = 2;
   optional transform.proto.Vector3d angular_velocity = 3;
 }
 
-// Proto representation of ::cartographer::sensor::CompressedRangeData
+// Proto representation of ::cartographer::sensor::CompressedRangeData.
 message CompressedRangeData {
   optional transform.proto.Vector3f origin = 1;
   optional CompressedPointCloud returns = 2;
   optional CompressedPointCloud misses = 3;
 }
+
+// Proto representation of ::cartographer::sensor::OdometryData.
+message OdometryData {
+  optional int64 timestamp = 1;
+  optional transform.proto.Rigid3d pose = 2;
+}