diff --git a/main/gps.go b/main/gps.go
index d64ef22d..798d9c55 100644
--- a/main/gps.go
+++ b/main/gps.go
@@ -78,6 +78,7 @@ type SituationData struct {
 	LastGPSTimeTime          time.Time // stratuxClock time since last GPS time received.
 	LastValidNMEAMessageTime time.Time // time valid NMEA message last seen
 	LastValidNMEAMessage     string    // last NMEA message processed.
+	PositionSampleRate       float64   // calculated sample rate of GPS positions
 
 	// From BMP180 pressure sensor.
 	Temp              float64
@@ -252,7 +253,7 @@ func initGPSSerial() bool {
 	} else {
 		// Byte order for UBX configuration is little endian.
 
-		// Set 10 Hz update to make gpsattitude more responsive.
+		// Set 10 Hz update to make gpsattitude more responsive for ublox7/8.
 		p.Write(makeUBXCFG(0x06, 0x08, 6, []byte{0x64, 0x00, 0x01, 0x00, 0x01, 0x00})) // 10 Hz
 		//p.Write(makeUBXCFG(0x06, 0x08, 6, []byte{0xc8, 0x00, 0x01, 0x00, 0x01, 0x00})) // 5 Hz
 
@@ -282,7 +283,7 @@ func initGPSSerial() bool {
 		qzss := []byte{0x05, 0x00, 0x03, 0x00, 0x00, 0x00, 0x01, 0x01}
 		glonass := []byte{0x06, 0x04, 0x0E, 0x00, 0x00, 0x00, 0x01, 0x01} // this disables GLONASS
 
-		if (device == "/dev/ublox8") || (device == "/dev/ttyAMA0") { // assume that any GPS connected to serial GPIO is ublox8 (RY835/6AI)
+		if (globalStatus.GPS_detected_type == GPS_TYPE_UBX8) || (globalStatus.GPS_detected_type == GPS_TYPE_UART) { // assume that any GPS connected to serial GPIO is ublox8 (RY835/6AI)
 			//log.Printf("UBX8 device detected on USB, or GPS serial connection in use. Attempting GLONASS configuration.\n")
 			glonass = []byte{0x06, 0x08, 0x0E, 0x00, 0x01, 0x00, 0x01, 0x01} // this enables GLONASS with 8-14 tracking channels
 		}
@@ -303,9 +304,7 @@ func initGPSSerial() bool {
 		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x00, 0x00, 0x05, 0x00, 0x05, 0x00, 0x01})) // GGA enabled every 5th message
 		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01})) // GLL disabled
 		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01})) // GSA disabled
-		//p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x02, 0x00, 0x05, 0x00, 0x05, 0x00, 0x01})) // GSA enabled disabled every 5th position (used for testing only)
 		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01})) // GSV disabled
-		//p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x03, 0x00, 0x05, 0x00, 0x05, 0x00, 0x01})) // GSV enabled for every 5th position (used for testing only)
 		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01})) // RMC
 		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01})) // VGT
 		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00})) // GRS
@@ -316,9 +315,9 @@ func initGPSSerial() bool {
 		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x0D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00})) // GNS
 		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x0E, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00})) // ???
 		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF0, 0x0F, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00})) // VLW
-		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF1, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00})) // Ublox,0
-		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF1, 0x03, 0x05, 0x05, 0x05, 0x05, 0x05, 0x00})) // Ublox,3
-		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF1, 0x04, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x00})) // Ublox,4
+		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF1, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00})) // Ublox,0
+		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF1, 0x03, 0x00, 0x05, 0x00, 0x05, 0x00, 0x00})) // Ublox,3
+		p.Write(makeUBXCFG(0x06, 0x01, 8, []byte{0xF1, 0x04, 0x00, 0x0A, 0x00, 0x0A, 0x00, 0x00})) // Ublox,4
 
 		// Reconfigure serial port.
 		cfg := make([]byte, 20)
@@ -531,7 +530,7 @@ func calcGPSAttitude() bool {
 	var lengthHeading, lengthSpeed int
 
 	center := float64(myGPSPerfStats[index].nmeaTime) // current time for calculating regression weights
-	halfwidth := float64(1.4)                         // width of regression evaluation window. Default of 1.4 seconds for 5 Hz sampling; can increase to 3.5 sec @ 1 Hz
+	halfwidth := float64(1.4)                         // width of regression evaluation window. Default of 1.4 seconds for 5 Hz sampling; will increase up to 3.5 sec @ 1 Hz
 
 	// frequency detection
 	tempSpeedTime = make([]float64, 0)
@@ -547,12 +546,14 @@ func calcGPSAttitude() bool {
 		if globalSettings.DEBUG {
 			log.Printf("GPS attitude: Average delta time is %.2f s (%.1f Hz)\n", dt_avg, 1/dt_avg)
 		}
-		halfwidth = 12 * dt_avg
+		halfwidth = 14 * dt_avg
+		mySituation.PositionSampleRate = 1 / dt_avg
 	} else {
 		if globalSettings.DEBUG {
 			log.Printf("GPS attitude: Couldn't determine sample rate\n")
 		}
-		halfwidth = 3.0
+		halfwidth = 3.5
+		mySituation.PositionSampleRate = 0
 	}
 
 	if halfwidth > 3.5 {