diff --git a/Dockerfile b/Dockerfile
index e2802ef..c0413b1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,3 +1,14 @@
+FROM ghcr.io/sdr-enthusiasts/docker-baseimage:base AS build
+
+RUN set -x && \
+    apt-get update -y && \
+    apt-get install -q -o Dpkg::Options::="--force-confnew" -y \
+        git gcc && \
+    cd / && \
+    git clone --depth=1 --single-branch https://github.com/sdr-enthusiasts/docker-vesselalert.git && \
+    cd /docker-vesselalert/src && \
+    gcc -static distance.c -o distance -lm -Ofast
+
 FROM ghcr.io/sdr-enthusiasts/docker-tar1090:latest
 
 LABEL org.opencontainers.image.source = "https://github.com/sdr-enthusiasts/docker-adsb-ultrafeeder"
@@ -58,6 +69,7 @@ RUN TEMP_PACKAGES=() && \
     echo "alias nano=\"nano -l\"" >> /root/.bashrc
 
 COPY rootfs/ /
+COPY --from=build /docker-vesselalert/src/distance /usr/local/bin/distance
 
 # Add Container Version
 RUN set -x && \
diff --git a/rootfs/etc/s6-overlay/s6-rc.d/gpsd_mlat_restart/dependencies.d/startup b/rootfs/etc/s6-overlay/s6-rc.d/gpsd_mlat_restart/dependencies.d/startup
new file mode 100644
index 0000000..e69de29
diff --git a/rootfs/etc/s6-overlay/s6-rc.d/gpsd_mlat_restart/run b/rootfs/etc/s6-overlay/s6-rc.d/gpsd_mlat_restart/run
new file mode 100755
index 0000000..8fefd29
--- /dev/null
+++ b/rootfs/etc/s6-overlay/s6-rc.d/gpsd_mlat_restart/run
@@ -0,0 +1,2 @@
+#!/bin/sh
+exec /etc/s6-overlay/scripts/gpsd_mlat_restart
diff --git a/rootfs/etc/s6-overlay/s6-rc.d/gpsd_mlat_restart/type b/rootfs/etc/s6-overlay/s6-rc.d/gpsd_mlat_restart/type
new file mode 100644
index 0000000..5883cff
--- /dev/null
+++ b/rootfs/etc/s6-overlay/s6-rc.d/gpsd_mlat_restart/type
@@ -0,0 +1 @@
+longrun
diff --git a/rootfs/etc/s6-overlay/s6-rc.d/user/contents.d/gpsd_mlat_restart b/rootfs/etc/s6-overlay/s6-rc.d/user/contents.d/gpsd_mlat_restart
new file mode 100644
index 0000000..e69de29
diff --git a/rootfs/etc/s6-overlay/scripts/gpsd_mlat_restart b/rootfs/etc/s6-overlay/scripts/gpsd_mlat_restart
new file mode 100755
index 0000000..787256e
--- /dev/null
+++ b/rootfs/etc/s6-overlay/scripts/gpsd_mlat_restart
@@ -0,0 +1,50 @@
+#!/command/with-contenv bash
+# shellcheck shell=bash disable=SC2015,SC2016,SC1091,SC2001,SC2154
+
+#---------------------------------------------------------------------------------------------
+# Copyright (C) 2023-2024, Ramon F. Kolb (kx1t) and contributors
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with this program.
+# If not, see <https://www.gnu.org/licenses/>.
+#---------------------------------------------------------------------------------------------
+
+source /scripts/common
+
+# Check if GPSD_IN has been enabled
+if ! grep -qi "gpsd_in" <<< "$ULTRAFEEDER_CONFIG" && ! grep -qi "gpsd_in" <<< "$ULTRAFEEDER_NET_CONNECTOR"; then
+    "${s6wrap[@]}" echo "GPSD not enabled - no need to check receiver location"
+    exec sleep infinity
+fi
+
+# Now wait a bit to allow GPS to establish itself
+sleep "${GPSD_INITIAL_WAIT:-300}"
+
+# Make sure that receiver.json exists; if it doesn't we need to wait for it
+while ! [[ -f /run/readsb/receiver.json ]]; do
+    sleep 1 & wait $!
+done
+
+# Get initial lat/lon/alt
+lat="$(jq -r .lat /run/readsb/receiver.json)"
+lon="$(jq -r .lon /run/readsb/receiver.json)"
+
+while :; do
+    sleep "${GPSD_CHECK_INTERVAL:30}" & wait $!
+    new_lat="$(jq -r .lat /run/readsb/receiver.json)"
+    new_lon="$(jq -r .lon /run/readsb/receiver.json)"
+    new_alt="$(jq -r .alt_m_amsl /run/readsb/receiver.json)"
+    distance="$(nice -n 20 distance "$lat" "$lon" "$new_lat" "$new_lon")"
+    if (( ${distance%%.*} > ${GPSD_MIN_DISTANCE} )); then
+        "${s6wrap[@]}" echo "Receiver moved ${distance%%.*} meters - restarting all mlat-clients"
+         pkill -f "/usr/bin/python3 /usr/bin/mlat-client" >/dev/null 2>&1
+    fi
+done
\ No newline at end of file
diff --git a/rootfs/etc/s6-overlay/scripts/mlat-client b/rootfs/etc/s6-overlay/scripts/mlat-client
index 16ed88c..68075e5 100755
--- a/rootfs/etc/s6-overlay/scripts/mlat-client
+++ b/rootfs/etc/s6-overlay/scripts/mlat-client
@@ -51,17 +51,17 @@ then
     exec sleep infinity
 fi
 
-if [[ -z "$LAT$READSB_LAT" ]]; then
-    "${s6wrap[@]}" --args echo "ERROR: READSB_LAT or LAT must be defined - MLAT will be disabled."
+if [[ -z "$LAT$READSB_LAT" ]] && ! grep -qi "gpsd_in" <<< "$ULTRAFEEDER_CONFIG" && ! grep -qi "gpsd_in" <<< "$ULTRAFEEDER_NET_CONNECTOR"; then
+    "${s6wrap[@]}" --args echo "ERROR: READSB_LAT or LAT must be defined or GPSD must be enabled - MLAT will be disabled."
     exec sleep infinity
 fi
 
-if [[ -z "$LONG$READSB_LON" ]]; then
-    "${s6wrap[@]}" --args echo "ERROR: READSB_LON or LONG must be defined - MLAT will be disabled."
+if [[ -z "$LONG$READSB_LON" ]] && ! grep -qi "gpsd_in" <<< "$ULTRAFEEDER_CONFIG" && ! grep -qi "gpsd_in" <<< "$ULTRAFEEDER_NET_CONNECTOR"; then
+    "${s6wrap[@]}" --args echo "ERROR: READSB_LON or LONG must be defined or GPSD must be enabled - MLAT will be disabled."
     exec sleep infinity
 fi
-if [[ -z "$ALT$READSB_ALT" ]]; then
-    "${s6wrap[@]}" --args echo "ERROR: READSB_ALT or ALT must be defined - MLAT will be disabled."
+if [[ -z "$ALT$READSB_ALT" ]] && ! grep -qi "gpsd_in" <<< "$ULTRAFEEDER_CONFIG" && ! grep -qi "gpsd_in" <<< "$ULTRAFEEDER_NET_CONNECTOR"; then
+    "${s6wrap[@]}" --args echo "ERROR: READSB_ALT or ALT must be defined or GPSD must be enabled - MLAT will be disabled."
     exec sleep infinity
 fi