diff --git a/advisorycircular.sh b/advisorycircular.sh
index 22ee7d3..a2ca56e 100644
--- a/advisorycircular.sh
+++ b/advisorycircular.sh
@@ -5,9 +5,9 @@ dir=$(dirname "$0")
 instance="$1"
 config_dir=/etc/advisorycircular
 run_dir=/var/run/advisorycircular
-sqb_path=/usr/local/share/run/advisorycircular/clean-basestation.sqb
+sqb_path=/usr/local/share/advisorycircular/clean-basestation.sqb
 
 config_path="$config_dir"/"$instance"-config.yaml
 secrets_path="$config_dir"/"$instance"-secrets.yaml
 history_path="$run_dir"/"$instance"-history.edn
-(cd "$run_dir" && "$dir"/intervalexec 10 node $dir/out/advisorycircular.js --config "$config_path" --secrets "$secrets_path" --basestation-sqb "$sqb_path" --history "$history_path")
+(cd "$run_dir" && "$dir"/intervalexec 10 node $dir/out/advisorycircular.js --config "$config_path" --secrets "$secrets_path" --basestation-sqb "$sqb_path" --history "$history_path" --log-prefix "$instance")
diff --git a/src/main/lemondronor/advisorycircular.cljs b/src/main/lemondronor/advisorycircular.cljs
index 403f306..0f0e38a 100644
--- a/src/main/lemondronor/advisorycircular.cljs
+++ b/src/main/lemondronor/advisorycircular.cljs
@@ -19,6 +19,9 @@
 
 (logging/deflog "advisorycircular" logger)
 
+(def log-prefix (atom ""))
+
+
 (defn get-basestation-sqb-record [icao db-path]
   (log-info "%s: Looking up in %s" icao db-path)
   (p/let [record
@@ -168,18 +171,19 @@
 (defn ac-desc [ac]
   (str (:icao ac) " " "http://tar1090.adsbexchange.com/?icao=" (:icao ac)
        " " (:lat ac) " " (:lon ac)
-       " #" (:registration ac) " " (:alt ac) " " (:curviness ac) " "
+       " " (:registration ac) " " (:alt ac) " " (:curviness ac) " "
        (:normalized-curviness ac)))
 
 
-(defn screenshot [icao lat lon]
-  (p/let [image-path
-          (adsbx/screenshot-aircraft icao lat lon
-                                     {:timeout 30000
-                                      ;;:headless? false
-                                      ;; :viewport {:width 1600 :height 800}
-                                      ;; :clip {:width 1600 :height 800 :x 0 :y 0}
-                                      })]
+(defn screenshot [icao lat lon now]
+  (p/let [image-path (str icao "-" (util/format-utc-ts now) ".png")
+          _ (adsbx/screenshot-aircraft icao lat lon
+                                       {:timeout 30000
+                                        :output-path image-path
+                                        ;;:headless? false
+                                        ;; :viewport {:width 1600 :height 800}
+                                        ;; :clip {:width 1600 :height 800 :x 0 :y 0}
+                                        })]
     (log-verbose "%s: Got screenshot" icao)
     image-path))
 
@@ -191,8 +195,8 @@
 
 (defn circling2? [ac config]
   (let [relevant-history (filter #(and (:alt %) (> (:alt %) 300)) (:history ac))]
-   (and (> (geo/flight-curviness relevant-history) (:curviness-threshold-degrees config))
-        (> (:alt ac) 300))))
+    (and (> (geo/flight-curviness relevant-history) (:curviness-threshold-degrees config))
+         (> (:alt ac) 300))))
 
 
 ;; Returns a vector of two elements,
@@ -436,7 +440,7 @@
 
 (defn track->geojson [older-positions recent-positions icao centroid]
   {:type "FeatureCollection"
-    :features
+   :features
    [(geojson-linestring older-positions
                         {:stroke "#c0070b"
                          :stroke-width 2
@@ -477,48 +481,48 @@
                 (:distance airport-properties)
                 (:minimum-airport-distance-km config)
                 (:label airport-properties)
-                ()))
-    (let [alts (map :alt recent-positions)
-          min-alt (apply min alts)
-          max-alt (apply max alts)
-          ratio (/ max-alt min-alt)]
-      (log-info "%s: ratio of min alt to max alt: %s [%s - %s]" icao (.toFixed (/ max-alt min-alt) 1) min-alt max-alt))
-    (do
-      (p/let [coarse (pelias/reverse (:pelias config) lat lon {:layers "coarse"})]
-        (let [coarse (first (:features coarse))]
-          (log-info "%s: Reverse geocode: %s" icao (:properties coarse))
-          ;; Note that if we're over the ocean we get null :(
-          (p/then (p/all [(screenshot (:icao ac) lat lon)
-                          (p/let [nearby (landmark config lat lon)
-                                  _ (log-info "WOOO %s" nearby)
-                                  sqb (if-let [sqb-path (:basestation-sqb config)]
-                                        (get-basestation-sqb-record icao sqb-path))]
-                            (let [description (generate-description ac sqb coarse nearby)]
-                              (log-info "Description: %s" description)
-                              description))])
-                  (fn [[image-path description]]
-                    (if (or (nil? coarse)
-                            ;; TODO: Filter using the layer hierarchy; we want
-                            ;; anything smaller than "region" (state).
-                            (= (get-in coarse [:properties :name]) "California"))
-                      (log-info "%s: Filtering out because it is outside Los Angeles County" (:icao ac))
-                      (if (and image-path description)
-                        (do
-                          (if (get-in config [:twitter :enabled?])
-                            (twitter/tweet (twitter/twit (:twitter config))
-                                           description
-                                           [image-path]
-                                           lat
-                                           lon)
-                            (log-warn "Skipping tweeting"))
-                          (let [path (str (.toFixed (/ now 1000) 0) "-" icao "-recent" ".geojson")]
-                            (util/write-file
-                             path
-                             (.stringify
-                              js/JSON
-                              (clj->js (track->geojson older-positions recent-positions icao centroid)))
-                             {})))
-                        (log-warn "Skipping tweet %s %s" image-path description))))))))))
+                ())
+      ;; (let [alts (map :alt recent-positions)
+      ;;       min-alt (apply min alts)
+      ;;       max-alt (apply max alts)
+      ;;       ratio (/ max-alt min-alt)]
+      ;;   (log-info "%s: ratio of min alt to max alt: %s [%s - %s]" icao (.toFixed (/ max-alt min-alt) 1) min-alt max-alt))
+      (do
+        (p/let [coarse (pelias/reverse (:pelias config) lat lon {:layers "coarse"})]
+          (let [coarse (first (:features coarse))]
+            (log-info "%s: Reverse geocode: %s" icao (:properties coarse))
+            ;; Note that if we're over the ocean we get null :(
+            (p/then (p/all [(screenshot (:icao ac) lat lon now)
+                            (p/let [nearby (landmark config lat lon)
+                                    _ (log-info "WOOO %s" nearby)
+                                    sqb (if-let [sqb-path (:basestation-sqb config)]
+                                          (get-basestation-sqb-record icao sqb-path))]
+                              (let [description (generate-description ac sqb coarse nearby)]
+                                (log-info "Description: %s" description)
+                                description))])
+                    (fn [[image-path description]]
+                      (if (or (nil? coarse)
+                              ;; TODO: Filter using the layer hierarchy; we want
+                              ;; anything smaller than "region" (state).
+                              (= (get-in coarse [:properties :name]) "California"))
+                        (log-info "%s: Filtering out because it is outside Los Angeles County" (:icao ac))
+                        (if (and image-path description)
+                          (do
+                            (if (get-in config [:twitter :enabled?])
+                              (twitter/tweet (twitter/twit (:twitter config))
+                                             description
+                                             [image-path]
+                                             lat
+                                             lon)
+                              (log-warn "Skipping tweeting"))
+                            (let [path (str icao "-" (util/format-utc-ts now) ".geojson")]
+                              (util/write-file
+                               path
+                               (.stringify
+                                js/JSON
+                                (clj->js (track->geojson older-positions recent-positions icao centroid)))
+                               {})))
+                          (log-warn "Skipping tweet %s %s" image-path description)))))))))))
 
 
 (defn process-potential-circles [acs config now]
@@ -536,7 +540,7 @@
    ;; This is how many degrees of turning we need to see over
    ;; max-history-age-ms ms to consider it a potential circling
    ;; aircraft.
-   :curviness-threshold-degrees (* 2 360)
+   :curviness-threshold-degrees (* 4 360)
    ;; If the centroid of the aircraft's positions is less than this
    ;; close to an airport, then it's probably just doing flight
    ;; training.
@@ -610,7 +614,12 @@
       (.option "--config <path>" "Path to the configuration yaml file")
       (.option "--secrets <path>" "Path to the secrets yaml file" "secrets.yaml")
       (.option "--history <path>" "Path to history/state file" "advisorycircular.edn")
+      (.option "--log-prefix <prefix>" "Log prefix to use")
       (.parse (.-argv js/process)))
+  (logging/set-log-prefix! (or (.-logPrefix commander) ""))
+  (reset! log-prefix (if (.-logPrefix commander)
+                       (str (.-logPrefix commander) "-")
+                       ""))
   (let [start-time (current-time)]
     ;; If --config-path is specified, definitely try to read that
     ;; file. Otherwise, only read config.yaml if it exists.
diff --git a/src/main/lemondronor/advisorycircular/logging.cljs b/src/main/lemondronor/advisorycircular/logging.cljs
index 600c47f..6b18b81 100644
--- a/src/main/lemondronor/advisorycircular/logging.cljs
+++ b/src/main/lemondronor/advisorycircular/logging.cljs
@@ -6,15 +6,34 @@
   (:require-macros
    [lemondronor.advisorycircular.logging]))
 
+
+;; (def format-msg [msg]
+;;   (gstring/format "%s%-7s %-9s/%-18s| %s"
+;;                                   (.-timestamp %)
+;;                                   (.-ms %)
+;;                                   (.-service %)
+;;                                   (.-level %)
+;;                                   (.-message %)))
+
+(def log-prefix (atom ""))
+
+(defn set-log-prefix! [prefix]
+  (swap! log-prefix (constantly prefix)))
+
+
+(defn format-msg [msg]
+  (let [prefix (if (and @log-prefix (> (count @log-prefix) 0))
+                 (str @log-prefix " ")
+                 "")]
+    (gstring/format "%s%s %s"
+                    prefix
+                    (.-level msg)
+                    (.-message msg))))
+
+
 (let [createLogger (.-createLogger winston)
       format (.-format winston)
-      transports (.-transports winston)
-      printf-fmt #(gstring/format "%s%-7s %-9s/%-18s| %s"
-                                  (.-timestamp %)
-                                  (.-ms %)
-                                  (.-service %)
-                                  (.-level %)
-                                  (.-message %))]
+      transports (.-transports winston)]
   (def logger (createLogger
                #js {:level "info"
                     :format (.combine
@@ -30,7 +49,7 @@
                     :defaultMeta #js {}}))
   (.add logger (new (.-Console transports)
                     #js {:format (.combine format
-                                           (.printf format printf-fmt))})))
+                                           (.printf format format-msg))})))
 
 
 (defn get-logger [service]
diff --git a/src/main/lemondronor/advisorycircular/util.cljs b/src/main/lemondronor/advisorycircular/util.cljs
index b396140..d2d0b5e 100644
--- a/src/main/lemondronor/advisorycircular/util.cljs
+++ b/src/main/lemondronor/advisorycircular/util.cljs
@@ -85,3 +85,15 @@
                    [[k]])))
              m))
     []))
+
+
+(defn format-utc-ts [millis]
+  (let [date (js/Date. millis)]
+    (str (.getUTCFullYear date)
+         (.getUTCMonth date)
+         (.getUTCDate date)
+         "-"
+         (.getUTCHours date)
+         (.getUTCMinutes date)
+         (.getUTCSeconds date)
+         (.getUTCMilliseconds date))))