package main import ( "fmt" // "time" "../uatparse" "os" "bufio" "strings" "unicode" "strconv" "github.com/gonum/plot" "github.com/gonum/plot/plotter" "github.com/gonum/plot/plotutil" "github.com/gonum/plot/vg" "sort" ) const ( UPLINK_FRAME_DATA_BYTES = 432 ) /* From AC 00-45G [http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_00-45G_CHG_1-2.pdf] 1.3.7.1 Flight Information Service – Broadcast (FIS-B) Table 1-1. FIS-B Over UAT Product Update and Transmission Intervals: Product FIS-B Over UAT Service Update Intervals(1) FIS-B Service Transmission Intervals(2) AIRMET As available 5 minutes Convective SIGMET As available 5 minutes METARs / SPECIs 1 minute / as available 5 minutes NEXRAD Composite Reflectivity (CONUS) 15 minutes 15 minutes NEXRAD Composite Reflectivity (Regional) 5 minutes 2.5 minutes NOTAMs-D/FDC/TFR As available 10 minutes PIREP As available 10 minutes SIGMET As available 5 minutes Special Use Airspace Status As available 10 minutes TAF/AMEND 8 hours/as available 10 minutes Temperature Aloft 12 hours 10 minutes Winds Aloft 12 hours 10 minutes (1) The Update Interval is the rate at which the product data is available from the source. (2) The Transmission Interval is the amount of time within which a new or updated product transmission must be completed and the rate or repetition interval at which the product is rebroadcast. */ func append_metars(rawUplinkMessage string, curMetars []string) []string { ret := curMetars uatMsg, err := uatparse.New(rawUplinkMessage) if err != nil { return ret } //fmt.Printf("*************************\n") metars, _ := uatMsg.GetTextReports() for _, v := range metars { //fmt.Printf("EE: %s\n", v) vSplit := strings.Split(v, " ") if vSplit[0] != "METAR" || len(vSplit) < 3 { // Only looking for METARs. continue } ret = append(ret, v) } //fmt.Printf("=========================\n") return ret } /* Average number of METARs received for an airport for which you first received a METAR in the first 5 minutes, over 10 minutes. Divided by two. */ func metar_qos_one_period(a, b []string) float64 { numMetarByIdent := make(map[string]uint) for _, v := range a { vSplit := strings.Split(v, " ") numMetarByIdent[vSplit[1]]++ } // b is treated differently - new airports in b aren't counted. for _, v := range b { vSplit := strings.Split(v, " ") if _, ok := numMetarByIdent[vSplit[1]]; ok { numMetarByIdent[vSplit[1]]++ } } // Final count. ret := float64(0.0) for _, num := range numMetarByIdent { ret += float64(num) } if len(numMetarByIdent) > 0 { ret = ret / float64(2 * len(numMetarByIdent)) } return ret } func main() { if len(os.Args) < 2 { fmt.Printf("%s \n", os.Args[0]) return } f, err := os.Open(os.Args[1]) if err != nil { fmt.Printf("error opening '%s': %s\n", os.Args[1], err.Error()) return } rdr := bufio.NewReader(f) // For now, "windows" are 5 minute intervals. qos := make(map[int64]float64) // window number -> qos value curWindow := int64(0) windowOffset := int64(0) metarsByWindow := make(map[int64][]string) for { buf, err := rdr.ReadString('\n') if err != nil { break } buf = strings.TrimFunc(buf, func(r rune) bool {return unicode.IsControl(r)}) linesplit := strings.Split(buf, ",") if len(linesplit) < 2 { // Blank line or invalid. continue } if linesplit[0] == "START" { // Reset ticker, new start. //TODO: Support multiple sessions. // Reset the counters, new session. // qos = make(map[uint]float64) // curWindowMetars = make([]string, 0) // curWindow = 0 windowOffset = curWindow } else { // If it's not "START", then it's a tick count. i, err := strconv.ParseInt(linesplit[0], 10, 64) if err != nil { fmt.Printf("invalid tick: '%s'\n\n\n%s\n", linesplit[0], buf) continue } // Window number in current session. wnum := int64(i / (5 * 60 * 1000000000)) // fmt.Printf("%d\n", curWindow) if wnum + windowOffset != curWindow { // Switched over. curWindow = wnum + windowOffset beforeLastWindowMetars, ok := metarsByWindow[curWindow - 2] lastWindowMetars, ok2 := metarsByWindow[curWindow - 1] if ok && ok2 { // fmt.Printf("%v\n\n\nheyy\n\n%v\n", beforeLastWindowMetars, lastWindowMetars) qos[curWindow - 1] = metar_qos_one_period(beforeLastWindowMetars, lastWindowMetars) fmt.Printf("qos=%f\n", qos[curWindow - 1]) delete(metarsByWindow, curWindow - 2) delete(metarsByWindow, curWindow - 1) } } metarsByWindow[curWindow] = append_metars(linesplit[1], metarsByWindow[curWindow]) } } // Make graph. p, err := plot.New() if err != nil { panic(err) } p.Title.Text = "Stratux FIS-B QoS vs. Time" p.X.Label.Text = "5 min intervals" p.Y.Label.Text = "QoS" // Loop through an ordered list of the periods, so that the line connects the right dots. var keys []int for k := range qos { keys = append(keys, int(k)) } sort.Ints(keys) pts := make(plotter.XYs, len(qos)) i := 0 for _,k := range keys { v := qos[int64(k)] fmt.Printf("%d, %f\n", k, v) pts[i].X = float64(k) pts[i].Y = v i++ } err = plotutil.AddLinePoints(p, "UAT", pts) if err != nil { panic(err) } if err := p.Save(4 * vg.Inch, 4 * vg.Inch, "qos.png"); err != nil { panic(err) } }