Station info - map view · info · telemetry · weather · raw · status · beacons · messages · bulletins · browse · moving · my account
Callsign, ship name or locator: Clear       
It is possible to search using wildcards (*?) after a prefix. Example: OH*
APRS station PA1CD-10 - show graphs
Comment: PA1CD-10 QTH Bolsward 144.800Mhz
Location: 53°04.19' N 5°32.21' E - locator JO23SB46KS - show map
0.4 miles Northeast bearing 35° from Bolsward, Sûdwest Fryslân, Friesland, Netherlands [?]
3.4 miles Southwest bearing 218° from Wommels, Gemeente Littenseradiel, Friesland, Netherlands
55.1 miles Northeast bearing 29° from Amsterdam, Gemeente Amsterdam, North Holland, Netherlands
86.0 miles Northeast bearing 37° from Den Haag, Gemeente ’s-Gravenhage, South Holland, Netherlands
Last position: 2024-11-17 03:35:41 EST (3m3s ago)
2024-11-17 09:35:41 CET local time at Bolsward, Netherlands [?]
Last telemetry: 2022-08-12 01:24:41 EDT (828d 3h14m ago) – show telemetry
Ch 1: 185, Ch 2: 196, Ch 3: 0, Ch 4: 0, Ch 5: 0
 1     2     3     4     5     6     7     8 
Device: Microsat: WX3in1 Plus 2.0
Last path: PA1CD-10>APMI06 via WIDE2-2,qAR,PA7D-10 (good)
Positions stored: 12
Packet rate: 306 seconds between packets on average during 15000 seconds.
Other SSIDs: PA1CD-13 PA1CD-9 PA1CD-Y PA1CD-1 PA1CD-7
APRS digipeater – Statistics for 2024-11:
Stations heard directly: 48 on radio path – show map
Last heard a station directly: 2024-11-17 02:39:48 EST (58m56s ago)
Normal receiver range estimate: 124 miles (Updated: 2024-11-17 02:39:48 EST)
Position packets heard directly: 3232 on radio path
Stations near current position of PA1CD-10 - show more
callsign distance last heard - EST      callsign distance last heard - EST
PA1CD-1324.1 yards 270°2024-11-17 03:37:03 PA3GFY B0.7 miles 223°2024-11-08 10:36:10
PA3GFY-B0.7 miles 223°2024-11-08 10:36:20 PA3GFY-70.7 miles 223°2024-11-16 16:47:02
PA3GFY-30.7 miles 223°2024-11-07 13:10:27 PA3GFY D0.7 miles 223°2024-11-17 03:37:50
PA3GFY-D0.7 miles 223°2024-11-17 03:37:40 PA3GOQ-31.2 miles 250°2024-10-21 15:07:42
EISVOGEL3.3 miles 159°2024-10-25 05:02:18 GW3103.5 miles 156°2024-10-24 05:07:21
PA1AIS-104.8 miles 130°2024-11-06 20:51:23 PA1AIS5.1 miles 145°2024-11-15 18:01:17
CALIDRIS5.2 miles 145°2024-11-08 05:32:46 PA2SNK5.2 miles 109°2024-11-15 10:00:12
REHOBOTH5.2 miles 175°2024-11-12 21:16:35 PA7AP-D5.3 miles 110°2024-11-16 20:14:16
KROMME MIJDRECHT5.3 miles 136°2024-10-19 04:25:15 AVIOR5.3 miles 136°2024-11-16 08:28:03
NIEUWE LIEFDE5.3 miles 136°2024-11-08 10:46:09 HALVE MAAN5.3 miles 136°2024-11-17 03:37:51
Stations which heard PA1CD-10 directly on radio –
callsign pkts first heard - EST last heard longest (tx => rx) longest at - EST
DB0KX-2 25 2024-11-04 07:11:09 2024-11-04 13:37:18 JO23SB > JO31EG 128.1 miles 164° 2024-11-04 13:37:18
PE1OEZ-2 227 2024-10-31 20:41:14 2024-11-17 00:50:41 JO23SB > JO23VE 13.3 miles 51° 2024-11-17 00:50:41
ON0LRG-2 5 2024-11-03 21:11:08 2024-11-04 04:21:07 JO23SB > JO20PJ 185.1 miles 183° 2024-11-04 04:21:07
OZ2DXE-2 4 2024-11-14 17:15:47 2024-11-14 18:05:48 JO23SB > JO46ML 273.4 miles 29° 2024-11-14 18:05:48
DB0OTV-2 1 2024-11-04 04:11:08 2024-11-04 04:11:08 JO23SB > JO31HG 132.9 miles 159° 2024-11-04 04:11:08
DB0SDA 6 2024-11-04 03:57:43 2024-11-04 08:37:13 JO23SB > JO30AS 160.0 miles 172° 2024-11-04 08:37:13
DB0ET 1009 2024-10-31 21:11:22 2024-11-16 17:05:43 JO23SB > JO33MJ 65.4 miles 69° 2024-11-16 17:05:43
ON0LB-10 3 2024-11-04 04:26:07 2024-11-04 08:36:07 JO23SB > JO20SR 161.0 miles 180° 2024-11-04 08:36:07
DL8KZ 11 2024-11-04 02:56:07 2024-11-04 14:41:06 JO23SB > JO30PQ 180.7 miles 155° 2024-11-04 14:41:06
DB0ROD 5 2024-11-01 04:51:13 2024-11-05 05:56:05 JO23SB > JO42QH 170.4 miles 107° 2024-11-05 05:56:05
F8KCS-2 1 2024-11-04 11:51:11 2024-11-04 11:51:11 JO23SB > JN19RN 257.8 miles 202° 2024-11-04 11:51:11
PD0R-10 6 2024-11-04 19:51:06 2024-11-05 00:21:06 JO23SB > JO22ED 80.3 miles 218° 2024-11-05 00:21:06
DB0RNG 1 2024-11-05 01:16:05 2024-11-05 01:16:05 JO23SB > JO43UA 171.6 miles 90° 2024-11-05 01:16:05
PI1SHB 76 2024-10-31 20:51:19 2024-11-15 16:34:48 JO23SB > JO21QQ 94.9 miles 185° 2024-11-15 16:34:48
PI1SWK 463 2024-10-31 22:26:15 2024-11-16 02:40:43 JO23SB > JO32BS 31.0 miles 129° 2024-11-16 02:40:43
DB0OL-10 959 2024-10-31 20:16:16 2024-11-16 03:20:47 JO23SB > JO43CD 112.2 miles 86° 2024-11-16 03:20:47
PI1SHB-2 68 2024-11-01 01:21:19 2024-11-15 15:20:48 JO23SB > JO21QQ 94.9 miles 185° 2024-11-15 15:20:48
PE1OYS-2 184 2024-10-31 20:01:14 2024-11-16 21:55:41 JO23SB > JO23WG 19.6 miles 50° 2024-11-16 21:55:41
DB0HFT-10 1 2024-11-01 16:57:19 2024-11-01 16:57:19 JO23SB > JO43JB 135.1 miles 89° 2024-11-01 16:57:19
DB0EMS-5 291 2024-10-31 20:51:14 2024-11-16 03:25:43 JO23SB > JO32SU 84.0 miles 100° 2024-11-16 03:25:43
DB0OX-10 164 2024-10-31 23:16:18 2024-11-16 01:25:46 JO23SB > JO33OO 77.1 miles 62° 2024-11-16 01:25:46
DL0PBS-5 56 2024-10-31 21:21:17 2024-11-16 01:35:46 JO23SB > JO33QB 76.8 miles 89° 2024-11-16 01:35:46
DL3DP-1 7 2024-11-04 08:06:07 2024-11-04 11:46:07 JO23SB > JO31PI 139.0 miles 148° 2024-11-04 11:46:07
ON4BN-11 1 2024-11-04 05:16:07 2024-11-04 05:16:07 JO23SB > JO21QB 138.3 miles 183° 2024-11-04 05:16:07
ON6YF-2 4 2024-11-03 03:21:09 2024-11-04 12:21:06 JO23SB > JO20KC 207.3 miles 188° 2024-11-04 12:21:06
DB0PBG-5 762 2024-10-31 20:06:15 2024-11-16 03:20:44 JO23SB > JO33QB 77.4 miles 89° 2024-11-16 03:20:44
ON4MAX-2 9 2024-11-03 22:17:02 2024-11-04 07:26:10 JO23SB > JO20TI 186.9 miles 179° 2024-11-04 07:26:10
DB0HHH-10 2 2024-11-05 01:31:06 2024-11-05 02:41:05 JO23SB > JO53CL 194.3 miles 79° 2024-11-05 02:41:05
DB0WOT 115 2024-11-02 23:46:40 2024-11-15 16:12:15 JO23SB > JO43MR 152.9 miles 71° 2024-11-15 16:12:15
ON0TVO 1 2024-11-04 12:01:45 2024-11-04 12:01:45 JO23SB > JO11UB 160.0 miles 210° 2024-11-04 12:01:45
PD2AVE-10 152 2024-10-31 21:11:14 2024-11-16 01:35:43 JO23SB > JO22FD 78.1 miles 216° 2024-11-16 01:35:43
DB0BOH-10 4 2024-11-04 12:01:10 2024-11-04 13:36:08 JO23SB > JO31HU 96.1 miles 151° 2024-11-04 13:36:08
ON0NR-10 2 2024-11-04 11:11:09 2024-11-04 11:12:08 JO23SB > JO20KJ 186.1 miles 189° 2024-11-04 11:12:08
ON0ANT-10 7 2024-11-03 23:11:35 2024-11-06 19:31:10 JO23SB > JO21FF 136.4 miles 201° 2024-11-06 19:31:10
DB0WHV 8 2024-11-04 20:31:14 2024-11-14 01:21:37 JO23SB > JO43BN 112.6 miles 71° 2024-11-14 01:21:37
PI1SNK-7 690 2024-10-31 20:06:16 2024-11-17 03:25:43 JO23SB > JO23TA 5.5 miles 123° 2024-11-17 03:25:43
PD2TJK 7 2024-11-03 17:26:08 2024-11-10 10:35:55 JO23SB > JO22NS 27.8 miles 220° 2024-11-10 10:35:55
PA3DJR 13 2024-11-03 23:21:08 2024-11-16 01:00:43 JO23SB > JO33MG 63.3 miles 77° 2024-11-16 01:00:43
DB0PDF-10 352 2024-10-31 21:06:14 2024-11-16 03:00:43 JO23SB > JO42CW 112.3 miles 94° 2024-11-16 03:00:43
DB0HSK-10 1 2024-11-03 14:01:08 2024-11-03 14:01:08 JO23SB > JO41DJ 164.4 miles 134° 2024-11-03 14:01:08
ON0LGE-2 25 2024-11-03 22:31:09 2024-11-04 14:52:34 JO23SB > JO20UO 169.0 miles 178° 2024-11-04 14:52:34
DL4QB 2 2024-11-04 20:11:06 2024-11-04 21:21:06 JO23SB > JO31QS 119.5 miles 139° 2024-11-04 21:21:06
PI1DHR-10 451 2024-10-31 20:16:14 2024-11-16 00:15:43 JO23SB > JO22IW 33.8 miles 257° 2024-11-16 00:15:43
PI6EHV-10 13 2024-11-04 03:51:07 2024-11-05 20:26:04 JO23SB > JO21RL 110.8 miles 181° 2024-11-05 20:26:04
DO9FK-10 1 2024-11-02 20:11:10 2024-11-02 20:11:10 JO23SB > JO33PM 77.9 miles 66° 2024-11-02 20:11:10
F1ZSG 3 2024-11-06 17:31:04 2024-11-15 13:10:45 JO23SB > JN38MA 353.7 miles 169° 2024-11-15 13:10:45
PA3X 6 2024-11-03 07:31:09 2024-11-05 18:51:04 JO23SB > JO22OF 58.9 miles 194° 2024-11-05 18:51:04
PA7D-10 3321 2024-10-31 20:06:14 2024-11-17 03:35:41 JO23SB > JO23VF 15.5 miles 40° 2024-11-17 03:35:41
ON0ABT-2 6 2024-11-04 10:26:37 2024-11-04 22:21:39 JO23SB > JO11PC 164.6 miles 216° 2024-11-04 22:21:39
PD5A-5 27 2024-10-31 22:21:14 2024-11-07 13:31:00 JO23SB > JO32AE 63.3 miles 161° 2024-11-07 13:31:00
DO1TOB 5 2024-11-04 03:41:07 2024-11-04 19:56:06 JO23SB > JO41HO 165.5 miles 127° 2024-11-04 19:56:06
PI6BLA 1 2024-11-04 12:21:37 2024-11-04 12:21:37 JO23SB > JO21PI 118.5 miles 186° 2024-11-04 12:21:37
ON9CC-10 1 2024-11-04 13:36:06 2024-11-04 13:36:06 JO23SB > JO20WS 160.6 miles 175° 2024-11-04 13:36:06
F1ZVV 3 2024-11-04 08:41:08 2024-11-04 23:31:07 JO23SB > JO00TR 231.9 miles 227° 2024-11-04 23:31:07
F8KII-4 1 2024-11-04 12:26:08 2024-11-04 12:26:08 JO23SB > JN09OV 287.4 miles 222° 2024-11-04 12:26:08
PI1DRV 99 2024-11-01 00:06:14 2024-11-16 02:10:43 JO23SB > JO22KE 65.5 miles 205° 2024-11-16 02:10:43
PB4C 1 2024-11-04 04:21:07 2024-11-04 04:21:07 JO23SB > JO20XW 148.2 miles 173° 2024-11-04 04:21:07
DG5IBS-4 2 2024-11-04 20:51:14 2024-11-05 05:51:16 JO23SB > JO42SU 166.3 miles 94° 2024-11-05 05:51:16
ON4JES-14 1 2024-11-04 09:16:07 2024-11-04 09:16:07 JO23SB > JO10HU 196.2 miles 220° 2024-11-04 09:16:07
PI1DHG-10 2 2024-11-04 10:56:07 2024-11-04 11:26:07 JO23SB > JO22EB 84.9 miles 217° 2024-11-04 11:26:07
DB0NGR 19 2024-11-06 12:11:02 2024-11-08 08:25:58 JO23SB > JO32LO 66.6 miles 119° 2024-11-08 08:25:58
DB0FRI 61 2024-10-31 21:21:14 2024-11-14 16:50:46 JO23SB > JO33SN 90.4 miles 68° 2024-11-14 16:50:46
F1PRY-14 10 2024-11-03 21:51:14 2024-11-04 13:16:08 JO23SB > JN09XI 298.6 miles 212° 2024-11-04 13:16:08
F6ZBZ-3 1 2024-11-15 21:50:44 2024-11-15 21:50:44 JO23SB > JN16FB 502.0 miles 197° 2024-11-15 21:50:44
DF0TWN-10 21 2024-11-04 02:51:07 2024-11-14 16:40:46 JO23SB > JO32OH 86.7 miles 127° 2024-11-14 16:40:46
DM0MAX 1 2024-11-04 15:26:07 2024-11-04 15:26:07 JO23SB > JO42IG 143.0 miles 111° 2024-11-04 15:26:07
PF5T-10 10 2024-11-02 18:06:10 2024-11-02 22:31:10 JO23SB > JO33AA 22.5 miles 100° 2024-11-02 22:31:10
PD1MV-2 1 2024-11-06 08:06:03 2024-11-06 08:06:03 JO23SB > JO33JD 52.6 miles 82° 2024-11-06 08:06:03

Only position packets which were originated by the station are shown here. The range statistics show some extra long hops, because some digipeaters do not correctly add themselves to the digipeater path. Please check the raw packets.
Stations heard directly by PA1CD-10
callsign pkts first heard - EST last heard longest (rx => tx) longest at - EST
PA7D-9 17 2024-11-01 13:25:37 2024-11-16 10:41:52 JO23VF > JO23SB 15.7 miles 40° 2024-11-02 18:50:18
DB0ET 241 2024-10-31 23:25:41 2024-11-16 01:45:25 JO33MJ > JO23SB 65.4 miles 69° 2024-11-16 01:45:25
PI1SHB 67 2024-11-03 15:58:10 2024-11-15 16:56:46 JO21QQ > JO23SB 94.9 miles 185° 2024-11-15 16:56:46
PA2SNK-5 21 2024-11-01 10:40:58 2024-11-01 14:15:20 JO23TA > JO23SB 6.3 miles 130° 2024-11-01 10:40:58
PA1AIS 118 2024-11-12 01:37:26 2024-11-15 18:00:49 JO22MW > JO23SB 22.2 miles 246° 2024-11-12 11:37:13
DB0OX-10 68 2024-11-02 00:42:16 2024-11-16 01:04:28 JO33OO > JO23SB 77.1 miles 62° 2024-11-16 01:04:28
PE2AM-9 23 2024-11-04 10:50:24 2024-11-14 08:50:10 JO33AD > JO23SB 20.6 miles 75° 2024-11-06 01:28:24
PD2CL-9 21 2024-11-08 02:52:09 2024-11-11 12:32:13 JO22VW > JO23SB 13.8 miles 131° 2024-11-11 12:32:13
PD5RT-15 6 2024-11-03 19:00:50 2024-11-06 22:00:29 JO32CD > JO23SB 71.0 miles 156° 2024-11-06 22:00:29
DB0PBG-5 248 2024-11-02 15:54:59 2024-11-16 02:23:42 JO33QB > JO23SB 77.4 miles 89° 2024-11-16 02:23:42
PD0RBX-9 1 2024-11-07 23:54:23 2024-11-07 23:54:23 JO22LO > JO23SB 40.4 miles 215° 2024-11-07 23:54:23
DB0BOH-10 1 2024-11-04 12:12:40 2024-11-04 12:12:40 JO31HU > JO23SB 96.1 miles 151° 2024-11-04 12:12:40
PA2RCW-9 227 2024-11-01 02:11:30 2024-11-15 18:01:26 JO22MW > JO23SB 21.7 miles 246° 2024-11-11 01:51:43
ON0ANT-10 92 2024-11-01 16:21:42 2024-11-15 21:13:30 JO21FF > JO23SB 136.4 miles 201° 2024-11-15 21:13:30
DB0WHV 20 2024-11-02 23:18:42 2024-11-15 23:28:00 JO43BN > JO23SB 112.6 miles 71° 2024-11-15 23:28:00
PD5HW-7 8 2024-11-01 12:07:05 2024-11-02 11:59:09 JO22XU > JO23SB 23.7 miles 126° 2024-11-02 11:59:09
PA3GOQ-9 36 2024-11-01 02:08:25 2024-11-12 10:56:14 JO23VE > JO23SB 13.5 miles 49° 2024-11-07 11:20:58
PD0RH-10 1 2024-11-07 01:35:34 2024-11-07 01:35:34 JO22IV > JO23SB 35.6 miles 250° 2024-11-07 01:35:34
PA2SNK-9 460 2024-11-04 01:29:06 2024-11-15 11:16:39 JO23UC > JO23SB 7.4 miles 76° 2024-11-06 06:01:28
PA1VHF 28 2024-11-04 14:14:44 2024-11-06 13:53:21 JO32CD > JO23SB 70.6 miles 156° 2024-11-06 13:53:21
PD1AQM-9 1 2024-11-07 01:25:15 2024-11-07 01:25:15 JO22IJ > JO23SB 59.1 miles 216° 2024-11-07 01:25:15
ON0LGE-2 11 2024-11-03 22:07:24 2024-11-04 12:02:23 JO20UO > JO23SB 169.0 miles 178° 2024-11-04 12:02:23
PD1ABA 2 2024-11-03 12:11:56 2024-11-03 12:26:56 JO22JM > JO23SB 50.2 miles 220° 2024-11-03 12:26:56
PI1DHR-10 31 2024-11-02 19:06:43 2024-11-14 22:06:43 JO22IW > JO23SB 33.8 miles 257° 2024-11-14 22:06:43
PA2HD-2 21 2024-11-03 20:40:40 2024-11-15 11:05:46 JO23WI > JO23SB 25.8 miles 37° 2024-11-15 11:05:46
PA3GFY-7 106 2024-11-07 14:35:46 2024-11-16 09:16:39 JO23SB > JO23SB 0.7 miles 222° 2024-11-11 16:01:36
DB0IK 5 2024-11-03 11:12:33 2024-11-03 19:27:33 JO50KP > JO23SB 281.8 miles 124° 2024-11-03 19:27:33
PD1XIE-7 3 2024-11-01 11:52:35 2024-11-10 10:50:27 JO23RB > JO23SB 1.6 miles 255° 2024-11-01 11:53:35
PD0FGQ-9 1 2024-11-02 16:49:10 2024-11-02 16:49:10 JO23VE > JO23SB 13.7 miles 54° 2024-11-02 16:49:10
PA7D-10 632 2024-10-31 20:17:52 2024-11-17 02:39:48 JO23VF > JO23SB 15.5 miles 40° 2024-11-17 02:39:48
ON0ABT-2 1 2024-11-04 12:17:27 2024-11-04 12:17:27 JO11PC > JO23SB 164.6 miles 216° 2024-11-04 12:17:27
PD4PM-9 39 2024-11-03 23:50:10 2024-11-14 23:23:12 JO33JK > JO23SB 57.5 miles 64° 2024-11-14 00:08:32
PA2DX-9 11 2024-11-01 02:56:25 2024-11-14 02:04:16 JO23XD > JO23SB 17.7 miles 68° 2024-11-04 14:23:11
PI6BLA 15 2024-11-04 11:33:23 2024-11-06 19:11:25 JO21PI > JO23SB 118.5 miles 186° 2024-11-06 19:11:25
PD2JG-9 13 2024-11-05 02:06:01 2024-11-05 02:41:28 JO22VW > JO23SB 13.9 miles 127° 2024-11-05 02:06:01
F1ZVV 1 2024-11-04 11:28:06 2024-11-04 11:28:06 JO00TR > JO23SB 231.9 miles 227° 2024-11-04 11:28:06
PA3GFY-3 149 2024-11-07 10:22:44 2024-11-07 13:10:23 JO23SB > JO23SB 0.7 miles 223° 2024-11-07 13:10:23
PE1AVG-7 1 2024-11-15 09:39:33 2024-11-15 09:39:33 JO23UA > JO23SB 6.6 miles 123° 2024-11-15 09:39:33
PA1HN-2 10 2024-11-05 10:23:07 2024-11-14 01:44:01 JO22NX > JO23SB 19.5 miles 248° 2024-11-14 01:44:01
PD1ANS-9 290 2024-11-02 09:17:24 2024-11-09 03:33:57 JO23SI > JO23SB 19.0 miles 4° 2024-11-07 14:27:58
PD1HK-9 62 2024-11-04 11:11:19 2024-11-15 01:19:00 JO33AA > JO23SB 21.5 miles 99° 2024-11-12 11:20:03
PA0AKV-1 2 2024-11-08 13:54:15 2024-11-08 13:55:23 JO22UW > JO23SB 11.1 miles 136° 2024-11-08 13:54:15
DB0NCU-1 32 2024-11-02 16:56:52 2024-11-15 23:30:26 JO32LM > JO23SB 70.4 miles 121° 2024-11-15 23:30:26
DM0NGU-1 60 2024-11-02 19:20:29 2024-11-16 01:24:00 JO32NI > JO23SB 83.4 miles 126° 2024-11-16 01:24:00
F1PRY-14 3 2024-11-04 11:56:50 2024-11-04 12:36:50 JN09XI > JO23SB 298.6 miles 212° 2024-11-04 12:36:50
PE1BBT-5 2 2024-11-04 13:04:14 2024-11-04 13:34:14 JO22MB > JO23SB 71.3 miles 197° 2024-11-04 13:34:14
PD1MV-2 5 2024-11-06 11:35:53 2024-11-06 14:50:53 JO33JD > JO23SB 52.6 miles 82° 2024-11-06 14:50:53
PA1ZF-2 19 2024-11-05 11:43:13 2024-11-14 09:52:51 JO23WF > JO23SB 18.9 miles 51° 2024-11-14 09:52:51

Only stations from which a position packet has been heard are shown here. The range statistics show some extra long hops, because some digipeaters do not correctly add themselves to the digipeater path. Please check the raw packets.
About this site
This page shows real-time information collected from the Automatic Position Reporting System Internet network (APRS-IS). APRS is used by amateur (ham) radio operators to transmit real-time position information, weather data, telemetry and messages over the radio. A vehicle equipped with a GPS receiver, a VHF transmitter or HF transceiver and a small computer device called a tracker transmits it's location, speed and course in a small data packet, which is then received by a nearby iGate receiving site which forwards the packet on the Internet. Systems connected to the Internet can send information on the APRS-IS without a radio transmitter, or collect and display information transmitted anywhere in the world.
User guide · FAQ · Blog · Discussion group · Linking to aprs.fi · AIS sites · Service status · Database statistics · Advertising on aprs.fi · Technical details · API · Change log · Planned changes · Credits and thanks · Terms Of Service · iPhone/iPad APRS