diff --git a/sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/calc/GNSSCalcService.java b/sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/calc/GNSSCalcService.java
new file mode 100644
index 00000000..8eb62cb6
--- /dev/null
+++ b/sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/calc/GNSSCalcService.java
@@ -0,0 +1,37 @@
+package com.imdroid.sideslope.calc;
+
+import com.imdroid.sideslope.bd.Tilt;
+import com.imdroid.sideslope.message.D341LocationMessage;
+
+import java.time.LocalDateTime;
+
+public interface GNSSCalcService {
+    /**
+     * 计算单条GNSS数据
+     *
+     * @param message GNSS数据
+     * @param completeWhenIdle 是否根据空闲时间判断本轮结束
+     * @return x,y,z三轴数据
+     */
+    double[] calcSingle(D341LocationMessage message, boolean completeWhenIdle);
+
+    /**
+     * 单轮解算结束，计算平滑值
+     */
+    void calSingleDone(String deviceId, Integer tenantId, LocalDateTime resultTime);
+
+    /**
+     * 根据GNSS数据的中间结果，计算出最终结果
+     *
+     * @param deviceId 设备id
+     * @return x,y,z三轴数据
+     */
+    //double[] calcResult(String deviceId,double[] b562Xyz, double[] tiltXyz);
+
+    /**
+     * 根据GNSS数据的中间结果，计算Tilt的平均值
+     * @param deviceid 设备id
+     * @return Tilt
+     */
+    Tilt calcAvgTilt(String deviceid);
+}