chore: release v0.27.12

bandopen_sources.go

@@ -93,14 +93,27 @@ func keepKnownBands(want []string) []string {
 	return out
 }
 
+// pskrMaxGrids bounds the receiver squares the broker is asked to filter on.
+// Each is one subscription, and the traffic follows the area: 2000 km is about
+// 615 squares, which the broker takes in batches without complaint. The cap is
+// there so an absurd radius cannot turn into thousands of subscriptions — past
+// it the nearest squares are kept, and the log says how many.
+const pskrMaxGrids = 900
+
 // bandOpenNearKm reads the stored receiver radius, falling back to the default
 // for anything unset or out of range. The bounds are the two ways to make the
 // watch useless: below 25 km almost nobody is ever near enough to hear anything,
-// and past 1000 km the reports stop being about the operator's own path — which
-// is the entire premise of measuring from a receiver rather than a transmitter.
+// and past 3000 km a "nearby" receiver is on the far side of a continent, which
+// says nothing about the operator's own path.
+//
+// The ceiling was 1000 km, chosen with Europe in mind, where that radius holds a
+// dozen countries' worth of receivers. It is the wrong number in VK: a station
+// there can have almost nobody inside 300 km, and the chase list stayed empty
+// not because nothing was on the air but because nothing was listening close
+// enough to count.
 func bandOpenNearKm(raw string) int {
 	n, err := strconv.Atoi(strings.TrimSpace(raw))
-	if err != nil || n < 25 || n > 1000 {
+	if err != nil || n < 25 || n > 3000 {
 		return pskr.DefaultNearKm
 	}
 	return n
@@ -194,7 +207,17 @@ func (a *App) startBandOpenFeed() {
 	// hundred survived the NearKm test below. One ring of squares — about the
 	// same 300 km — is 0.2 to 1.2 a second, and the same for every operator,
 	// where filtering by DXCC ranged from 1.2 (OH) to 72.5 (K).
-	rxGrids := geo.NeighbourGrids(a.opLat, a.opLon, 1)
+	//
+	// The set follows the radius the operator asked for. It was one fixed ring
+	// whatever they set — about 300 km — so raising the radius bought nothing:
+	// the reports that would have satisfied it were never sent to us in the
+	// first place, and an operator in a thinly-populated region who widened the
+	// circle to find some receivers saw no change at all.
+	rxGrids := geo.GridsWithin(a.opLat, a.opLon, float64(s.NearKm), pskrMaxGrids)
+	if len(rxGrids) == 0 {
+		rxGrids = geo.NeighbourGrids(a.opLat, a.opLon, 1)
+	}
+	applog.Printf("pskr: receiver filter — %d squares within %d km of the station", len(rxGrids), s.NearKm)
 
 	var onGrid func(call, grid string)
 	if chaseGrids {