diff --git a/libraries/AP_RangeFinder/AP_RangeFinder.h b/libraries/AP_RangeFinder/AP_RangeFinder.h
index f9ffb4e4f819e1..a25ad2209679e6 100644
--- a/libraries/AP_RangeFinder/AP_RangeFinder.h
+++ b/libraries/AP_RangeFinder/AP_RangeFinder.h
@@ -174,8 +174,10 @@ class RangeFinder
 #if AP_RANGEFINDER_JRE_SERIAL_ENABLED
         JRE_Serial = 41,
 #endif
-#if AP_RANGEFINDER_SIM_ENABLED
+#if AP_RANGEFINDER_RDS02UF_ENABLED
         RDS02UF = 42,
+#endif
+#if AP_RANGEFINDER_SIM_ENABLED
         SIM = 100,
 #endif
     };
diff --git a/libraries/AP_RangeFinder/AP_RangeFinder_RDS02UF.cpp b/libraries/AP_RangeFinder/AP_RangeFinder_RDS02UF.cpp
index bdfe34ebb2493e..2218f6ff3e286a 100644
--- a/libraries/AP_RangeFinder/AP_RangeFinder_RDS02UF.cpp
+++ b/libraries/AP_RangeFinder/AP_RangeFinder_RDS02UF.cpp
@@ -19,202 +19,111 @@
  * Azimuth Coverage ±17°,Elevation Coverage ±3°
  * Frame Rate 20Hz
  */
-#include "AP_RangeFinder_RDS02UF.h"
+
+#include "AP_RangeFinder_config.h"
 
 #if AP_RANGEFINDER_RDS02UF_ENABLED
 
+#include "AP_RangeFinder_RDS02UF.h"
 #include <AP_HAL/AP_HAL.h>
-#include <ctype.h>
+
+extern const AP_HAL::HAL& hal;
 
 #define RDS02_HEAD1                 0x55
 #define RDS02_HEAD2                 0x55
 #define RDS02_END                   0xAA
-#define RDS02UF_HEAD_LEN            2
-#define RDS02UF_ERROR_CODE_INDEX    3
-#define RDS02UF_PRODUCTS_FC_INDEX_L 4
-#define RDS02UF_PRODUCTS_FC_INDEX_H 5
 #define RDS02UF_PRE_DATA_LEN        6
-#define RDS02UF_DATA_LEN            10
-#define RDS02_DATA_Y_INDEX_L        13
-#define RDS02_DATA_Y_INDEX_H        14
 #define RDS02_TARGET_FC_INDEX_L     8
 #define RDS02_TARGET_FC_INDEX_H     9
 #define RDS02_TARGET_INFO_FC        0x070C
-#define RDS02UF_DIST_MAX_M          20.0
-#define RDS02UF_DIST_MIN_M          1.5
 #define RDS02UF_IGNORE_ID_BYTE      0x0F0F
 #define RDS02UF_UAV_PRODUCTS_ID     0x03FF
-#define RDS02UF_TIMEOUT_MS          200
 #define RDS02UF_IGNORE_CRC          0xFF
-#define RDS02UF_NO_ERR          0x00
+#define RDS02UF_NO_ERR              0x00
 
-extern const AP_HAL::HAL& hal;
-
-// return last value measured by sensor
-bool AP_RangeFinder_RDS02UF::get_reading(float &reading_m)
+bool AP_RangeFinder_RDS02UF::get_reading(float &distance_m)
 {
     if (uart == nullptr) {
         return false;
     }
 
-    // read any available data from the lidar
-    float sum = 0.0f;
-    uint16_t count = 0;
-    uint32_t nbytes = MAX(uart->available(), 1024U);
-    while (nbytes-- > 0) {
-        int16_t c = uart->read();
-        if (c < 0) {
-            continue;
-        }
-        if (decode(c)) {
-            sum += _distance_m;
-            count++;
-        }
+    const uint32_t nbytes = uart->read(&u.parse_buffer[body_length],
+                                 ARRAY_SIZE(u.parse_buffer)-body_length);
+    if (nbytes == 0) {
+        return false;
     }
+    body_length += nbytes;
+
+    move_header_in_buffer(0);
 
-    if (AP_HAL::millis() - state.last_reading_ms > RDS02UF_TIMEOUT_MS) {
-        set_status(RangeFinder::Status::NoData);
-        reading_m = 0.0f;
+    // header byte 1 is correct.
+    if (body_length < ARRAY_SIZE(u.parse_buffer)) {
+        // need a full buffer to have a valid message...
         return false;
     }
 
-    // return false if no new readings
-    if (count == 0) {
+    if (u.packet.headermagic2 != RDS02_HEAD2) {
+        move_header_in_buffer(1);
         return false;
     }
 
-    // return average of all measurements
-    reading_m = sum / count;
-    update_status();
-    return true;
-}
+    const uint16_t read_len = u.packet.length_h << 8 | u.packet.length_l;
+    if (read_len != RDS02UF_DATA_LEN) {
+        // we can only accept the fixed length message
+        move_header_in_buffer(1);
+        return false;
+    }
 
+    // check for the footer signatures:
+    if (u.packet.footermagic1 != RDS02_END) {
+        move_header_in_buffer(1);
+        return false;
+    }
+    if (u.packet.footermagic2 != RDS02_END) {
+        move_header_in_buffer(1);
+        return false;
+    }
 
-// add a single character to the buffer and attempt to decode
-// returns true if a distance was successfully decoded
-bool AP_RangeFinder_RDS02UF::decode(uint8_t c)
-{
-    uint8_t data = c;
-    bool ret = false;
-    switch (decode_state){
-        case RDS02UF_PARSE_STATE::STATE0_SYNC_1:
-            if (data == RDS02_HEAD1) {
-                parser_buffer[parser_index++] = data;
-                decode_state = RDS02UF_PARSE_STATE::STATE1_SYNC_2;
-            }
-            break;
-        case RDS02UF_PARSE_STATE::STATE1_SYNC_2:
-            if (data == RDS02_HEAD2) {
-                parser_buffer[parser_index++] = data;
-                decode_state = RDS02UF_PARSE_STATE::STATE2_ADDRESS;
-            } else {
-                parser_index = 0;
-                decode_state = RDS02UF_PARSE_STATE::STATE0_SYNC_1;
-            }
-            break;
-        case RDS02UF_PARSE_STATE::STATE2_ADDRESS: // address
-            parser_buffer[parser_index++] = data;
-            decode_state = RDS02UF_PARSE_STATE::STATE3_ERROR_CODE;
-            break;
-        case RDS02UF_PARSE_STATE::STATE3_ERROR_CODE: // error_code
-            parser_buffer[parser_index++] = data;
-            decode_state = RDS02UF_PARSE_STATE::STATE4_FC_CODE_L;
-            break;
-        case RDS02UF_PARSE_STATE::STATE4_FC_CODE_L: // fc_code low
-            parser_buffer[parser_index++] = data;
-            decode_state = RDS02UF_PARSE_STATE::STATE5_FC_CODE_H;
-            break;
-        case RDS02UF_PARSE_STATE::STATE5_FC_CODE_H: // fc_code high
-            parser_buffer[parser_index++] = data;
-            decode_state = RDS02UF_PARSE_STATE::STATE6_LENGTH_L;
-            break;
-        case RDS02UF_PARSE_STATE::STATE6_LENGTH_L: // lengh_low
-            parser_buffer[parser_index++] = data;
-            decode_state = RDS02UF_PARSE_STATE::STATE7_LENGTH_H;
-            break;
-        case RDS02UF_PARSE_STATE::STATE7_LENGTH_H:{ // lengh_high
-            uint8_t read_len = data << 8 | parser_buffer[parser_index-1];
-            // rds02uf data length is always 10
-            if (read_len == RDS02UF_DATA_LEN) {
-                parser_buffer[parser_index++] = data;
-                decode_state = RDS02UF_PARSE_STATE::STATE8_REAL_DATA;
-            } else {
-                parser_index = 0;
-                decode_state = RDS02UF_PARSE_STATE::STATE0_SYNC_1;
-            }
-            break;
-        }
-        case RDS02UF_PARSE_STATE::STATE8_REAL_DATA: // real_data
-            parser_buffer[parser_index++] = data;
-            if (parser_index == (RDS02UF_HEAD_LEN + RDS02UF_PRE_DATA_LEN + RDS02UF_DATA_LEN) ) {
-                decode_state = RDS02UF_PARSE_STATE::STATE9_CRC;
-            }
-            break;
-        case RDS02UF_PARSE_STATE::STATE9_CRC:{ // crc
-        #if RDS02_USE_CRC
-	        const uint8_t crc_data = crc8(&parser_buffer[2], RDS02UF_PRE_DATA_LEN + RDS02UF_DATA_LEN);
-            if (data == crc_data || data == RDS02UF_IGNORE_CRC) { // 0xff indicates that the current frame does not need to be checked.
-                parser_buffer[parser_index++] = data;
-                decode_state = RDS02UF_PARSE_STATE::STATE10_END_1;
-            } else {
-                parser_index = 0;
-                decode_state = RDS02UF_PARSE_STATE::STATE0_SYNC_1;
-            }
-        #else
-            parser_buffer[parser_index++] = data;
-            decode_state = RDS02UF_PARSE_STATE::STATE10_END_1;
-        #endif
-            break;
-        }
-        case RDS02UF_PARSE_STATE::STATE10_END_1:
-            if (data == RDS02_END) {
-                parser_buffer[parser_index++] = data;
-                decode_state = RDS02UF_PARSE_STATE::STATE11_END_2;
-            } else {
-                parser_index = 0;
-                decode_state = RDS02UF_PARSE_STATE::STATE0_SYNC_1;
-            }
-            break;
-        case RDS02UF_PARSE_STATE::STATE11_END_2:{
-            uint16_t fc_code = (parser_buffer[RDS02UF_PRODUCTS_FC_INDEX_H] << 8 | parser_buffer[RDS02UF_PRODUCTS_FC_INDEX_L]);
-            uint8_t err_code = parser_buffer[RDS02UF_ERROR_CODE_INDEX];
-            if (data == RDS02_END) {
-                if (fc_code == RDS02UF_UAV_PRODUCTS_ID && err_code == RDS02UF_NO_ERR) {// get targer information
-                    uint16_t read_info_fc = (parser_buffer[RDS02_TARGET_FC_INDEX_H] << 8 | parser_buffer[RDS02_TARGET_FC_INDEX_L]);
-                    if ((read_info_fc & RDS02UF_IGNORE_ID_BYTE) == RDS02_TARGET_INFO_FC){	// read_info_fc = 0x70C + ID * 0x10, ID: 0~0xF
-                        _distance_m = (parser_buffer[RDS02_DATA_Y_INDEX_H] * 256 + parser_buffer[RDS02_DATA_Y_INDEX_L]) / 100.0f;
-                        if (_distance_m > RDS02UF_DIST_MAX_M) {
-                            _distance_m = RDS02UF_DIST_MAX_M;
-                            set_status(RangeFinder::Status::OutOfRangeHigh);
-                        } else if (_distance_m < RDS02UF_DIST_MIN_M) {
-                            _distance_m = RDS02UF_DIST_MIN_M;
-                            set_status(RangeFinder::Status::OutOfRangeLow);
-                        }
-                        ret = true;
-                        state.last_reading_ms = AP_HAL::millis();
-                    }
-                }
-            }
-			parser_index = 0;
-			decode_state = RDS02UF_PARSE_STATE::STATE0_SYNC_1;
-			break;
+    // calculate checksum
+    const uint8_t checksum = crc8_rds02uf(&u.parse_buffer[2], RDS02UF_PRE_DATA_LEN + RDS02UF_DATA_LEN);
+    if (u.packet.checksum != checksum && u.packet.checksum != RDS02UF_IGNORE_CRC) {
+        move_header_in_buffer(1);
+        return false;
+    }
+
+    const uint16_t fc_code = (u.packet.fc_high << 8 | u.packet.fc_low);
+    if (fc_code == RDS02UF_UAV_PRODUCTS_ID && u.packet.error_code == RDS02UF_NO_ERR) {
+        // get target information
+        const uint16_t read_info_fc = (u.packet.data[1] << 8 | u.packet.data[0]);
+        if ((read_info_fc & RDS02UF_IGNORE_ID_BYTE) == RDS02_TARGET_INFO_FC) {
+            // read_info_fc = 0x70C + ID * 0x10, ID: 0~0xF
+            distance_m = (u.packet.data[6] * 256 + u.packet.data[5]) * 0.01f;
+            state.last_reading_ms = AP_HAL::millis();
         }
     }
 
-    return ret;
+    // reset buffer
+    body_length = 0;
+    return true;
 }
 
-uint8_t AP_RangeFinder_RDS02UF::crc8(uint8_t* pbuf, int32_t len)
+// find a RDS02UF message in the buffer, starting at
+// initial_offset.  If found, that message (or partial message) will
+// be moved to the start of the buffer.
+void AP_RangeFinder_RDS02UF::move_header_in_buffer(uint8_t initial_offset)
 {
-#if RDS02_USE_CRC
-     uint8_t crc = 0;
-     uint8_t* data = pbuf;
-     while (len--)
-        crc = crc8_table[crc^*(data++)];
-     return crc;
-#else
-    return 0;
-#endif
+    uint8_t header_offset;
+    for (header_offset=initial_offset; header_offset<body_length; header_offset++) {
+        if (u.parse_buffer[header_offset] == RDS02_HEAD1) {
+            break;
+        }
+    }
+    if (header_offset != 0) {
+        // header was found, but not at index 0; move it back to start of array
+        memmove(u.parse_buffer, &u.parse_buffer[header_offset], body_length - header_offset);
+        body_length -= header_offset;
+    }
 }
 
-#endif  // AP_RANGEFINDER_RDS02UF_ENABLED
\ No newline at end of file
+#endif  // AP_RANGEFINDER_RDS02UF_ENABLED
+
diff --git a/libraries/AP_RangeFinder/AP_RangeFinder_RDS02UF.h b/libraries/AP_RangeFinder/AP_RangeFinder_RDS02UF.h
index d9b8b6fc4400a4..e4fc161c091649 100644
--- a/libraries/AP_RangeFinder/AP_RangeFinder_RDS02UF.h
+++ b/libraries/AP_RangeFinder/AP_RangeFinder_RDS02UF.h
@@ -15,18 +15,17 @@
 
 #pragma once
 
-#include "AP_RangeFinder.h"
-#include "AP_RangeFinder_Backend_Serial.h"
-
-#ifndef AP_RANGEFINDER_RDS02UF_ENABLED
-#define AP_RANGEFINDER_RDS02UF_ENABLED AP_RANGEFINDER_BACKEND_DEFAULT_ENABLED
-#endif
+#include "AP_RangeFinder_config.h"
 
 #if AP_RANGEFINDER_RDS02UF_ENABLED
 
-// In order to save MCU resources, CRC check is not used
-#define RDS02_USE_CRC 0
-#define RDS02_BUFFER_SIZE 50
+#include "AP_RangeFinder.h"
+#include "AP_RangeFinder_Backend_Serial.h"
+
+#define RDS02_BUFFER_SIZE           50
+#define RDS02UF_DIST_MAX_CM         2000
+#define RDS02UF_DIST_MIN_CM         150
+#define RDS02UF_DATA_LEN            10
 
 class AP_RangeFinder_RDS02UF : public AP_RangeFinder_Backend_Serial
 {
@@ -45,11 +44,23 @@ class AP_RangeFinder_RDS02UF : public AP_RangeFinder_Backend_Serial
         return MAV_DISTANCE_SENSOR_RADAR;
     }
 
-
 private:
     using AP_RangeFinder_Backend_Serial::AP_RangeFinder_Backend_Serial;
 
-    // Data Format for Benewake Rds02UF
+    // find a RDS02UF message in the buffer, starting at
+    // initial_offset.  If found, that message (or partial message) will
+    // be moved to the start of the buffer.
+    void move_header_in_buffer(uint8_t initial_offset);
+
+    // get a distance reading
+    bool get_reading(float &reading_m) override;
+    uint16_t read_timeout_ms() const override { return 500; }
+
+    // make sure readings go out-of-range when necessary
+    int16_t max_distance_cm()const override  { return MIN(params.max_distance_cm, RDS02UF_DIST_MAX_CM); }
+    int16_t min_distance_cm() const override { return MAX(params.min_distance_cm, RDS02UF_DIST_MIN_CM); }
+
+     // Data Format for Benewake Rds02UF
     // ===============================
     // 21 bytes total per message:
     // 1) 0x55
@@ -64,68 +75,28 @@ class AP_RangeFinder_RDS02UF : public AP_RangeFinder_Backend_Serial
     // 10) CRC8
     // 11) END_1 0xAA
     // 12) END_2 0xAA
-    /// enum for handled messages
-    enum class RDS02UF_PARSE_STATE {
-        STATE0_SYNC_1 = 0,
-        STATE1_SYNC_2,
-        STATE2_ADDRESS,
-        STATE3_ERROR_CODE,
-        STATE4_FC_CODE_L,
-        STATE5_FC_CODE_H,
-        STATE6_LENGTH_L,
-        STATE7_LENGTH_H,
-        STATE8_REAL_DATA,
-        STATE9_CRC,
-        STATE10_END_1,
-        STATE11_END_2
+    struct PACKED RDS02UFPacket {
+        uint8_t headermagic1;
+        uint8_t headermagic2;
+        uint8_t address;
+        uint8_t error_code;
+        uint8_t fc_low;
+        uint8_t fc_high;
+        uint8_t length_l;
+        uint8_t length_h;
+        uint8_t data[RDS02UF_DATA_LEN];
+        uint8_t checksum;
+        uint8_t footermagic1;
+        uint8_t footermagic2;
     };
 
-    RDS02UF_PARSE_STATE decode_state;
-    uint8_t parser_index;
-    uint8_t parser_buffer[RDS02_BUFFER_SIZE];
-    float _distance_m;
-
-    // get a distance reading
-    bool get_reading(float &reading_m) override;
-    uint16_t read_timeout_ms() const override { return 3000; }
-    uint8_t crc8(uint8_t *pbuf, int32_t len);
-    bool decode(uint8_t c);
-
-#if RDS02_USE_CRC
-    const uint8_t crc8_table[256] = {
-        0x93,0x98,0xE4,0x46,0xEB,0xBA,0x04,0x4C,
-        0xFA,0x40,0xB8,0x96,0x0E,0xB2,0xB7,0xC0,
-        0x0C,0x32,0x9B,0x80,0xFF,0x30,0x7F,0x9D,
-        0xB3,0x81,0x58,0xE7,0xF1,0x19,0x7E,0xB6,
-        0xCD,0xF7,0xB4,0xCB,0xBC,0x5C,0xD6,0x09,
-        0x20,0x0A,0xE0,0x37,0x51,0x67,0x24,0x95,
-        0xE1,0x62,0xF8,0x5E,0x38,0x15,0x54,0x77,
-        0x63,0x57,0x6D,0xE9,0x89,0x76,0xBE,0x41,
-        0x5D,0xF9,0xB1,0x4D,0x6C,0x53,0x9C,0xA2,
-        0x23,0xC4,0x8E,0xC8,0x05,0x42,0x61,0x71,
-        0xC5,0x00,0x18,0x6F,0x5F,0xFB,0x7B,0x11,
-        0x65,0x2D,0x8C,0xED,0x14,0xAB,0x88,0xD5,
-        0xD9,0xC2,0x36,0x34,0x7C,0x5B,0x3C,0xF6,
-        0x48,0x0B,0xEE,0x02,0x83,0x79,0x17,0xE6,
-        0xA8,0x78,0xF5,0xD3,0x4E,0x50,0x52,0x91,
-        0xD8,0xC6,0x22,0xEC,0x3B,0xE5,0x3F,0x86,
-        0x06,0xCF,0x2B,0x2F,0x3D,0x59,0x1C,0x87,
-        0xEF,0x4F,0x10,0xD2,0x7D,0xDA,0x72,0xA0,
-        0x9F,0xDE,0x6B,0x75,0x56,0xBD,0xC7,0xC1,
-        0x70,0x1D,0x25,0x92,0xA5,0x31,0xE2,0xD7,
-        0xD0,0x9A,0xAF,0xA9,0xC9,0x97,0x08,0x33,
-        0x5A,0x99,0xC3,0x16,0x84,0x82,0x8A,0xF3,
-        0x4A,0xCE,0xDB,0x29,0x0F,0xAE,0x6E,0xE3,
-        0x8B,0x07,0x3A,0x74,0x47,0xB0,0xBB,0xB5,
-        0x7A,0xAA,0x2C,0xD4,0x03,0x3E,0x1A,0xA7,
-        0x27,0x64,0x06,0xBF,0x55,0x73,0x1E,0xFE,
-        0x49,0x01,0x39,0x28,0xF4,0x26,0xDF,0xDD,
-        0x44,0x0D,0x21,0xF2,0x85,0xB9,0xEA,0x4B,
-        0xDC,0x6A,0xCA,0xAC,0x12,0xFC,0x2E,0x2A,
-        0xA3,0xF0,0x66,0xE8,0x60,0x45,0xA1,0x8D,
-        0x68,0x35,0xFD,0x8F,0x9E,0x1F,0x13,0xD1,
-        0xAD,0x69,0xCC,0xA4,0x94,0x90,0x1B,0x43,
+    union RDS02UF_Union {
+        uint8_t parse_buffer[21];
+        struct RDS02UFPacket packet;
     };
-#endif
+    RDS02UF_Union u;
+
+    // number of bytes currently in the buffer
+    uint8_t body_length;
 };
 #endif  // AP_RANGEFINDER_RDS02UF_ENABLED
diff --git a/libraries/AP_RangeFinder/AP_RangeFinder_config.h b/libraries/AP_RangeFinder/AP_RangeFinder_config.h
index a6c793c340517b..37b50abf30f468 100644
--- a/libraries/AP_RangeFinder/AP_RangeFinder_config.h
+++ b/libraries/AP_RangeFinder/AP_RangeFinder_config.h
@@ -133,6 +133,10 @@
 #define AP_RANGEFINDER_PULSEDLIGHTLRF_ENABLED AP_RANGEFINDER_BACKEND_DEFAULT_ENABLED
 #endif
 
+#ifndef AP_RANGEFINDER_RDS02UF_ENABLED
+#define AP_RANGEFINDER_RDS02UF_ENABLED AP_RANGEFINDER_BACKEND_DEFAULT_ENABLED && BOARD_FLASH_SIZE > 1024
+#endif
+
 #ifndef AP_RANGEFINDER_SIM_ENABLED
 #define AP_RANGEFINDER_SIM_ENABLED (CONFIG_HAL_BOARD == HAL_BOARD_SITL && AP_RANGEFINDER_BACKEND_DEFAULT_ENABLED)
 #endif