diff --git a/libraries/AP_GPS/AP_GPS_SBP.cpp b/libraries/AP_GPS/AP_GPS_SBP.cpp
index ca53afbcde..53dd75938e 100644
--- a/libraries/AP_GPS/AP_GPS_SBP.cpp
+++ b/libraries/AP_GPS/AP_GPS_SBP.cpp
@@ -413,7 +413,7 @@ struct PACKED log_SbpLLH {
 
 struct PACKED log_SbpHealth {
     LOG_PACKET_HEADER;
-    uint32_t timestamp;
+    uint64_t time_us;
     uint32_t crc_error_counter;
     uint32_t last_injected_data_ms;
     uint32_t last_iar_num_hypotheses;
@@ -421,7 +421,7 @@ struct PACKED log_SbpHealth {
 
 struct PACKED log_SbpRAW1 {
     LOG_PACKET_HEADER;
-    uint32_t timestamp;
+    uint64_t time_us;
     uint16_t msg_type;
     uint16_t sender_id;
     uint8_t msg_len;
@@ -430,7 +430,7 @@ struct PACKED log_SbpRAW1 {
 
 struct PACKED log_SbpRAW2 {
     LOG_PACKET_HEADER;
-    uint32_t timestamp;
+    uint64_t time_us;
     uint16_t msg_type;
     uint8_t data2[192];
 };
@@ -438,11 +438,11 @@ struct PACKED log_SbpRAW2 {
 
 static const struct LogStructure sbp_log_structures[] PROGMEM = {
     { LOG_MSG_SBPHEALTH, sizeof(log_SbpHealth),
-      "SBPH", "IIII",   "TimeMS,CrcError,LastInject,IARhyp" },
+      "SBPH", "QIII",   "TimeUS,CrcError,LastInject,IARhyp" },
     { LOG_MSG_SBPRAW1, sizeof(log_SbpRAW1),
-      "SBR1", "IHHBZ",      "TimeMS,msg_type,sender_id,msg_len,d1" },
+      "SBR1", "QHHBZ",      "TimeUS,msg_type,sender_id,msg_len,d1" },
     { LOG_MSG_SBPRAW2, sizeof(log_SbpRAW2),
-      "SBR2", "IHZZZ",      "TimeMS,msg_type,d2,d3,d4" }
+      "SBR2", "QHZZZ",      "TimeUS,msg_type,d2,d3,d4" }
 };
 
 void
@@ -466,7 +466,7 @@ AP_GPS_SBP::logging_log_full_update()
 
     struct log_SbpHealth pkt = {
         LOG_PACKET_HEADER_INIT(LOG_MSG_SBPHEALTH),
-        timestamp       : hal.scheduler->millis(),
+        time_us                    : hal.scheduler->micros64(),
         crc_error_counter          : crc_error_counter,
         last_injected_data_ms      : last_injected_data_ms,
         last_iar_num_hypotheses    : last_iar_num_hypotheses,
@@ -492,11 +492,11 @@ AP_GPS_SBP::logging_log_raw_sbp(uint16_t msg_type,
 
     logging_write_headers();
 
-    uint32_t now = hal.scheduler->millis();
+    uint64_t time_us = hal.scheduler->micros64();
 
     struct log_SbpRAW1 pkt = {
         LOG_PACKET_HEADER_INIT(LOG_MSG_SBPRAW1),
-        timestamp       : now,
+        time_us         : time_us,
         msg_type        : msg_type,
         sender_id       : sender_id,
         msg_len         : msg_len,
@@ -508,7 +508,7 @@ AP_GPS_SBP::logging_log_raw_sbp(uint16_t msg_type,
 
         struct log_SbpRAW2 pkt2 = {
             LOG_PACKET_HEADER_INIT(LOG_MSG_SBPRAW2),
-            timestamp       : now,
+            time_us         : time_us,
             msg_type        : msg_type,
         };
         memcpy(pkt2.data2, &msg_buff[64], msg_len - 64);
diff --git a/libraries/AP_GPS/AP_GPS_UBLOX.cpp b/libraries/AP_GPS/AP_GPS_UBLOX.cpp
index 407af112b3..aad5bc14bc 100644
--- a/libraries/AP_GPS/AP_GPS_UBLOX.cpp
+++ b/libraries/AP_GPS/AP_GPS_UBLOX.cpp
@@ -273,7 +273,7 @@ void AP_GPS_UBLOX::log_mon_hw(void)
     }
     struct log_Ubx1 pkt = {
         LOG_PACKET_HEADER_INIT(LOG_UBX1_MSG),
-        timestamp  : hal.scheduler->millis(),
+        time_us    : hal.scheduler->micros64(),
         instance   : state.instance,
         noisePerMS : _buffer.mon_hw_60.noisePerMS,
         jamInd     : _buffer.mon_hw_60.jamInd,
@@ -297,7 +297,7 @@ void AP_GPS_UBLOX::log_mon_hw2(void)
 
     struct log_Ubx2 pkt = {
         LOG_PACKET_HEADER_INIT(LOG_UBX2_MSG),
-        timestamp : hal.scheduler->millis(),
+        time_us   : hal.scheduler->micros64(),
         instance  : state.instance,
         ofsI      : _buffer.mon_hw2.ofsI,
         magI      : _buffer.mon_hw2.magI,
@@ -313,7 +313,7 @@ void AP_GPS_UBLOX::log_accuracy(void) {
     }
     struct log_Ubx3 pkt = {
         LOG_PACKET_HEADER_INIT(LOG_UBX3_MSG),
-        timestamp  : hal.scheduler->millis(),
+        time_us  : hal.scheduler->micros64(),
         instance   : state.instance,
         hAcc     : state.horizontal_accuracy,
         vAcc     : state.vertical_accuracy,
@@ -329,11 +329,11 @@ void AP_GPS_UBLOX::log_rxm_raw(const struct ubx_rxm_raw &raw)
     if (gps._DataFlash == NULL || !gps._DataFlash->logging_started()) {
         return;
     }
-    uint32_t now = hal.scheduler->millis();
+    uint64_t now = hal.scheduler->micros64();
     for (uint8_t i=0; i<raw.numSV; i++) {
         struct log_GPS_RAW pkt = {
             LOG_PACKET_HEADER_INIT(LOG_GPS_RAW_MSG),
-            timestamp  : now,
+            time_us    : now,
             iTOW       : raw.iTOW,
             week       : raw.week,
             numSV      : raw.numSV,