backport NavSat message for bridge compatibility

proto/ignition/msgs/navsat.proto

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2021 Open Source Robotics Foundation
+ *
+ * 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.
+ *
+*/
+
+syntax = "proto3";
+package ignition.msgs;
+option java_package = "com.ignition.msgs";
+option java_outer_classname = "NavSatProtos";
+
+/// \ingroup ignition.msgs
+/// \interface NavSat
+/// \brief Data from a NavSat sensor
+/// This replaces the GPS message.
+
+import "ignition/msgs/header.proto";
+
+message NavSat
+{
+  /// \brief Optional header data
+  Header header                = 1;
+
+  /// \brief Latitude in degrees
+  double latitude_deg          = 2;
+
+  /// \brief Longitude in degrees
+  double longitude_deg         = 3;
+
+  /// \brief Altitude in meters
+  double altitude              = 4;
+
+  /// \brief East velocity in the ENU frame, in m / s
+  double velocity_east         = 5;
+
+  /// \brief North velocity in the ENU frame, in m / s
+  double velocity_north        = 6;
+
+  /// \brief Up velocity in the ENU frame, in m / s
+  double velocity_up           = 7;
+
+  /// \brief ID of reference frame
+  string frame_id              = 8;
+}