Skimmer frequency accuracy
To be a good RBN citizen a skimmer should have a frequency accuracy of 2ppm or better.
VERY IMPORTANT: To use the data below to improve the accuracy of your skimmer, multiply the current value of FreqCalibration in your skimmer software’s settings file with the suggested adjustment factor listed below.
The location of the settings files are:
CW Skimmer Server: %appdata%\Afreet\Products\SkimSrv\SkimSrv.ini
CW Skimmer: %appdata%\Afreet\Products\CwSkimmer\CwSkimmer.ini
The data listed below is based on yesterday’s RBN data, 00:00 to 23:59 UTC. This means that when making adjustments, changes in calibration will typically not have full impact on the listed data until the second day after the change.
The deviation estimates are based on spots on all active bands (40m and higher) from the respective skimmer. If different hardware is used for the different bands, the deviation number may thus not represent the actual deviation for a particular band. It is a good practice to run a separate instance of RBN Aggregator with a unique SSID for each hardware, (SM7IUN-1, SM7IUN-2, etc.)
A link to the software used to produce the tables can be found at the bottom of this page. It runs as a cron job in an Ubuntu container on my Synology server and uploads to this WordPress website shortly after midnight UTC daily.
The deviation estimation is done in two steps. The first step uses a small number of highly accurate skimmers (called “anchors” in the code, typically GPSDO-controlled skimmers) as reference. The whole estimation process is then repeated one more time but using both the anchors as well as all skimmers determined to be the “good” as reference. The “good” skimmers are those with less than 0.15ppm average deviation from the anchors, producing more than 100 qualifying spots (the qualification criteria of spots are outlined below.)
Repeating the analysis with this this extended set of skimmers as frequency references drastically increases the geographical coverage of the analysis thereby increasing the number of qualifying spots which means a much more reliable deviation estimates for all skimmers. The skimmers used as reference skimmers in the second stage (i.e. both anchors and “good”) are marked with an asterisk in the table below.
When looking at the numbers, keep in mind that the deviations estimated by the algorithm are 100 to 1000 times smaller than the 100Hz resolution of RBN frequency data. The input data is thus extremely “noisy” which inevitably leads to statistical variations. This is also the reason for not including spots under a certain frequency. Doing so would skew the statistics and cause underestimation of the frequency error.
Due to propagation characteristics, operator behavior (e.g. small QSY), and just statistical variations due to the 100Hz rounding, some skimmers selected as reference skimmers in the first stage may have more than 0.2ppm deviation in the second stage. This is not an error.
If you do not see your skimmer in the list below in spite of it successfully feeding spots to RBN the most likely reason is that it is off in frequency. The analytics discards all spots from skimmers having more than 0.5kHz frequency error.
if you want to implement an automated calibration of your skimmer you can access the skew data in machine-readable CSV format here https://sm7iun.se/rbnskew.csv
462796 RBN spots between 2024-11-20 00:00 and 23:59 UTC. 169749 spots (36.7%) were from reference skimmers (*). Average spot flow was 321 per minute from 196 active CW skimmers. 252635 spots from 194 skimmers qualified for analysis by meeting the following criteria: * Mode of spot is CW. * Also spotted by a reference skimmer within 1000 spots. * Also spotted by a reference skimmer within 10s. * SNR is 3dB or higher. * Frequency is 7000kHz or higher. * Frequency deviation from reference skimmer is 0.5kHz or less. * At least 5 spots from same skimmer in data set. Skimmer [ppm] Spots Adjustment ------------------------------------- 2E0INH* +0.1 2201 1.000000096 3B8CW +0.3 49 1.000000349 3D2AG +4.1 329 1.000004124 3V8SS +0.4 698 1.000000363 5Z4GO +1.2 12 1.000001188 AA0O +0.2 454 1.000000246 AC0C-1* -0.1 2427 0.999999928 BA6KC -0.0 155 0.999999992 BH4RRG +0.1 107 1.000000100 BH4XDZ -0.0 89 0.999999960 BI4MPH-1 +0.1 65 1.000000055 CT1EYQ -0.5 2387 0.999999475 CX7ACH +18.3 25 1.000018345 DC8YZ* +0.0 3023 1.000000011 DD5XX -1.0 2351 0.999999032 DE1LON -0.7 2223 0.999999279 DF2CK -0.2 4267 0.999999767 DF7GB* -0.1 2015 0.999999935 DJ1RK -0.2 1710 0.999999828 DK0TE* +0.1 2120 1.000000098 DK1MAX -0.2 48 0.999999777 DK3UA -8.0 904 0.999992034 DK9IP +12.5 1396 1.000012514 DK9IP-1 -0.2 1822 0.999999836 DL0LA -0.3 1047 0.999999684 DL0PF +3.3 4601 1.000003293 DL1EFW +1.5 669 1.000001531 DL1HWS* -0.0 2444 0.999999959 DL1HWS-3 +0.2 1280 1.000000169 DL8LAS -2.0 3664 0.999998003 DL8TG* -0.1 1832 0.999999942 DM5GG -0.2 3037 0.999999828 DM6EE* -0.0 1826 0.999999965 DP7D -8.9 167 0.999991144 DR4W -3.9 2519 0.999996105 EA1URA -0.4 1912 0.999999626 EA2CW -0.3 2071 0.999999717 EA2RCF-4 -0.1 1353 0.999999887 EA5RQ -0.0 394 0.999999985 EA5WU* +0.0 2376 1.000000023 ES2RR* -0.0 1941 0.999999951 F4GOU +4.0 1920 1.000003997 F4VVG -0.1 1108 0.999999880 F6IIT -0.8 3024 0.999999189 F6KGL +0.2 1803 1.000000187 F8DGY -0.9 1155 0.999999072 F8UKP -0.6 8 0.999999405 G0KTN* +0.1 2246 1.000000058 G3XBI +0.3 869 1.000000271 G3YPP +0.0 161 1.000000030 G4AON +0.6 99 1.000000620 G4FRE +1.2 777 1.000001176 G4HSO +0.3 113 1.000000253 G4IRN* +0.0 2874 1.000000005 G4ZFE* +0.1 2670 1.000000143 GI4DOH* -0.1 1485 0.999999945 HA1VHF -3.1 2296 0.999996928 HA5PP +4.6 14 1.000004587 HA6PX* -0.1 2148 0.999999884 HA8TKS* +0.1 1505 1.000000099 HB9BXE* +0.0 1838 1.000000030 HB9DCO -0.5 1471 0.999999542 HG0Y +7.1 5 1.000007128 HG8A -0.6 2292 0.999999424 IK3STG +3.8 1140 1.000003779 IK4VET +0.9 2642 1.000000914 IZ2CPS -0.6 176 0.999999403 JH7CSU1 +1.5 192 1.000001546 JI1HFJ -1.5 37 0.999998456 JJ2VLY -0.8 40 0.999999209 JK1QLQ +0.0 14 1.000000000 JN1ILK -2.4 491 0.999997611 K1RA* +0.0 2472 1.000000038 K2PO/7 +0.2 1225 1.000000245 K3LR +0.6 1663 1.000000594 K3PA-1* -0.0 1036 0.999999955 K3PA-2 -1.4 426 0.999998559 K4PP* -0.0 1541 0.999999963 K5EM -0.4 1163 0.999999594 K5TR +0.3 1601 1.000000286 K6FOD -0.1 989 0.999999949 K7CO* +0.2 1371 1.000000223 K7EK* +0.1 448 1.000000099 K7MJG +0.1 231 1.000000062 K9IMM* -0.0 2042 0.999999964 K9LC +0.2 2486 1.000000210 K9QC +0.8 497 1.000000803 KA7OEI +0.1 246 1.000000120 KD2OGR +0.3 1107 1.000000308 KH6LC -0.0 184 0.999999955 KM3T* -0.0 1739 0.999999996 KM3T-2 +0.2 2222 1.000000159 KM3T-3* +0.2 2622 1.000000185 KO7SS -0.8 808 0.999999175 KV4TT* -0.0 2367 0.999999998 LA6TPA -6.9 1067 0.999993075 LB9KJ -0.2 380 0.999999819 LU8XW +0.0 6 1.000000000 LZ3CB* +0.0 960 1.000000048 LZ4AE -0.4 1829 0.999999618 LZ4UX* +0.0 1567 1.000000043 LZ5DI* -0.0 1875 0.999999962 LZ7AA +0.6 1817 1.000000604 MM0ZBH* -0.2 2942 0.999999798 MM3NDH +0.1 2202 1.000000149 N2QT -0.3 122 0.999999737 N6TV +0.5 1125 1.000000509 N7TUG +16.0 167 1.000016001 N8DXE +1.3 785 1.000001287 N9CO* +0.0 2051 1.000000036 ND7K -1.8 1936 0.999998196 NG7M* +0.0 1034 1.000000025 NN3RP -0.5 977 0.999999515 NU4F -0.1 1787 0.999999900 OE6ADD* +0.1 2049 1.000000124 OE6TZE* +0.1 1651 1.000000083 OE9GHV* -0.0 2728 0.999999975 OG66X -0.7 123 0.999999304 OH4KA -1.3 759 0.999998708 OH6BG -0.1 1830 0.999999863 OH8KA +3.6 450 1.000003618 OK1FCJ* +0.1 2574 1.000000064 OK1HRA -4.0 2444 0.999996040 ON4EM +0.8 36 1.000000791 ON6ZQ -0.4 1613 0.999999632 OZ1AAB* +0.1 564 1.000000121 OZ1BZS +0.4 535 1.000000434 OZ4ADX +0.6 221 1.000000646 PA0MBO +0.3 1110 1.000000278 PA4009 +65.7 26 1.000065750 PA5WT -0.2 57 0.999999812 PA8MM* -0.0 1563 0.999999959 PE5TT +0.2 1921 1.000000184 PI4CC* -0.1 2830 0.999999889 PR1T -4.0 94 0.999995985 R1LB -5.8 317 0.999994198 R6YY +0.2 130 1.000000219 RK3TD +0.9 2166 1.000000869 RN4WA +0.9 1316 1.000000877 RU9CZD -8.3 961 0.999991724 S50ARX* -0.1 2133 0.999999908 S50U* -0.1 822 0.999999879 S53A +0.5 2822 1.000000543 SE5E -0.2 2668 0.999999797 SM7IUN* +0.0 2200 1.000000008 SQ5OUO +6.4 1639 1.000006423 SV1CDN -0.3 642 0.999999656 SZ1A -0.2 1546 0.999999845 TF3Y +1.6 2193 1.000001560 TI7W +0.2 2757 1.000000243 TK0C +0.0 8 1.000000000 TK0C-2 +0.7 106 1.000000706 UA0S -3.5 811 0.999996466 UY2RA -0.7 32 0.999999332 V51YJ +1.4 109 1.000001394 VE3EID +0.4 46 1.000000387 VE6AO -2.0 1188 0.999998016 VE6JY +1.6 1582 1.000001616 VE6WZ +4.7 1665 1.000004660 VE7CC +1.0 869 1.000000964 VK2GEL +0.5 362 1.000000505 VK2RH -0.2 87 0.999999836 VK3RASA -0.9 123 0.999999118 VK6ANC -1.1 148 0.999998862 VU2CPL +0.0 28 1.000000000 VU2PTT -0.0 129 0.999999972 W1NT-2* +0.0 2242 1.000000008 W1NT-6* -0.0 3087 0.999999998 W2MV +0.1 346 1.000000123 W2NAF +1.6 1857 1.000001625 W3DAN +1.5 772 1.000001456 W3LPL -2.6 808 0.999997423 W3OA* +0.1 2462 1.000000101 W3OA-1* +0.1 903 1.000000094 W3RGA -0.1 2455 0.999999940 W4KAZ -1.0 50 0.999999004 W8WWV -1.7 2045 0.999998259 WA7LNW* +0.0 2011 1.000000049 WB6BEE* -0.1 1743 0.999999908 WC2L* -0.1 2267 0.999999884 WC8GOP +8.7 178 1.000008659 WE9V* -0.2 2289 0.999999782 WS2C +4.0 1641 1.000003964 WS3W +1.3 328 1.000001316 WV4P +0.2 3435 1.000000244 WZ7I* +0.0 3014 1.000000015 XV9Q -0.2 24 0.999999802 YO2CK* +0.0 2211 1.000000045 YO2MAX* +0.1 2401 1.000000092 YO4RDW +7.8 232 1.000007777 YO5LD +0.2 197 1.000000217 ZL3X -0.7 480 0.999999299 ZL4YL +1.1 558 1.000001060 ZS1NN -3.5 71 0.999996483 Last updated 2024-11-21 00:15:43 UTC
Historical skimmer frequency accuracy
Below you will find historical accuracy data for the past ten days. Do not be concerned over minor daily variations. Since RBN spots only have 100Hz frequency accuracy, the input data is very noisy. Even for a perfectly accurate skimmer, the typical RMS rounding error across all shortwave bands is around 3ppm. This means that for a skimmer with 1000 spots per day the statistical variation is up to 0.2ppm. For skimmers with less than 100 spots per day the statistical variation can be above 2ppm. The content of the table below is based on the historical content of the above table.
Skimmer 1120 1119 1118 1117 1116 1115 1114 1113 1112 1111 --------------------------------------------------------------------- 2E0INH +0.1 +0.1 +0.1 +0.0 +0.1 +0.1 +0.0 +0.0 +0.1 +0.0 3B8CW +0.3 +0.0 +0.4 +0.0 +0.4 +0.0 +0.1 +0.2 +1.2 +0.0 3D2AG +4.1 +3.9 +3.7 +3.1 3V8SS +0.4 +2.6 -1.2 -1.8 -1.6 -1.5 -1.3 -1.2 -1.0 -1.5 5Z4GO +1.2 +0.5 +0.0 +0.5 +0.4 +0.0 +0.0 +0.9 7N4XCV -0.3 +0.0 +0.3 +0.4 +0.3 AA0O +0.2 +0.2 +0.4 +0.1 -0.0 -0.1 +0.6 +0.2 +0.3 +0.5 AC0C-1 -0.1 -0.0 +0.0 +0.1 +0.3 +0.3 +0.3 +0.3 +0.3 +0.4 BA6KC -0.0 -0.1 +0.1 -0.0 +0.0 +0.2 +0.1 -0.1 +0.1 +0.1 BD7JNA +0.5 -0.7 -0.0 -0.1 +0.0 +0.4 BG0AJO -0.2 -0.0 +0.1 BG2TFW -10.6 -11.0 -5.7 -11.9 -14.8 -12.1 -13.1 -12.5 -12.2 BG4GOV +0.3 +0.1 +0.5 BH4RRG +0.1 +0.0 +0.1 +0.0 +0.1 +0.4 -0.3 -0.0 +0.1 +0.1 BH4SCF +11.7 +8.0 +10.5 BH4XDZ -0.0 +0.1 +0.0 -0.1 +0.2 +0.2 +0.2 +0.0 +0.1 -0.2 BH4XDZ-1 +1.5 +0.2 -1.8 BI4MPH-1 +0.1 +0.0 +0.0 +0.1 +0.2 +0.2 +0.4 -0.0 +0.1 +0.0 BI4SSB +0.2 +0.4 +0.5 +0.1 +0.3 +0.2 +0.0 CT1EYQ -0.5 -0.5 -0.3 -0.5 -0.6 +0.6 +1.1 +1.1 -0.2 -0.1 CT7ANO +4.0 +4.0 +4.7 CX7ACH +18.3 +18.9 +18.9 +17.8 +19.0 +19.3 DC8YZ +0.0 +0.1 +0.1 +0.0 +0.1 +0.1 +0.1 +0.0 +0.2 +0.0 DD5XX -1.0 -0.8 -1.0 -1.5 -0.7 -0.8 -1.4 -1.1 -0.6 -0.8 DE1LON -0.7 -0.6 -0.5 -0.5 -0.4 -0.1 +0.0 +0.4 +0.5 +0.1 DF2CK -0.2 -0.1 +0.0 +0.0 +0.2 +0.1 +0.1 -0.0 -0.1 -0.1 DF7GB -0.1 +0.1 -0.0 -0.1 -0.1 +0.0 +0.0 -0.0 +0.0 +0.1 DG6FL +0.2 +0.3 +0.3 DJ1RK -0.2 -0.2 -0.3 -0.3 -0.6 -0.2 -0.4 -0.4 -0.5 -0.4 DK0TE +0.1 +0.1 +0.2 +0.2 +0.2 +0.3 +0.0 +0.1 +0.1 -0.1 DK1MAX -0.2 -0.2 -0.1 +0.0 +0.0 -0.0 -0.0 -0.0 DK3UA -8.0 -7.5 -8.4 -4.3 -5.6 -7.8 -6.4 -7.2 -6.8 -8.7 DK8NE -2.7 DK9IP-1 -0.2 -0.1 -0.2 -0.1 -0.0 -0.1 -0.1 -0.1 +0.1 DK9IP +12.5 -11.6 -12.4 -10.8 -11.7 -0.3 -0.2 -0.1 -0.2 -0.1 DL0LA -0.3 -0.1 -0.2 +0.0 -0.1 +0.0 DL0PF +3.3 +3.5 +3.3 +2.9 +2.9 +3.2 +2.7 +2.3 +3.4 +3.7 DL1EFW +1.5 +1.5 +1.6 +1.2 DL1HWS -0.0 -0.0 -0.0 -0.0 -0.1 -0.0 -0.0 -0.1 +0.1 -0.1 DL1HWS-3 +0.2 +0.2 +0.2 +0.1 +0.1 +0.2 +0.1 +0.1 +0.2 +0.3 DL3OBQ +0.6 +0.5 +0.0 -1.6 -2.9 DL5RCN +11.5 +11.3 +11.1 +11.9 +10.6 DL8LAS -2.0 -1.7 -1.7 -1.7 -1.8 -1.1 -1.7 -1.5 -1.8 DL8TG -0.1 -0.1 -0.1 -0.0 -0.0 +0.1 -0.0 -0.1 +0.1 -0.1 DM5GG -0.2 -0.2 -0.1 -0.2 -0.2 -0.1 -0.2 -0.2 -0.2 -0.3 DM6EE -0.0 -0.0 -0.0 +0.0 +0.0 -0.0 -0.1 +0.2 +0.0 DP7D -8.9 -6.7 -0.7 -1.8 +13.0 DR4W -3.9 -3.6 -3.3 -3.9 -3.3 -2.6 -3.9 -4.1 -3.1 -1.9 E28AC +2.7 +2.4 +1.0 EA1RX -0.5 -3.1 EA1URA -0.4 -0.3 -0.3 -0.4 -0.4 -0.4 -0.6 -0.5 -0.2 -0.2 EA2CW -0.3 -0.3 -0.2 -0.4 -0.4 -0.4 -0.3 -0.2 -0.1 +0.0 EA2RCF-4 -0.1 -0.2 -0.1 -0.2 -0.2 -0.1 -0.3 -0.1 -0.1 -0.0 EA5RQ -0.0 +0.0 +0.3 +0.2 +0.4 +0.3 +0.1 +0.3 +0.3 +0.3 EA5RQ/A +0.0 +0.0 +0.1 +0.2 +0.1 +0.3 +0.0 +0.0 EA5WU +0.0 -0.1 -0.1 -0.1 -0.0 +0.1 +0.0 ES2RR -0.0 +0.1 -0.0 -0.0 -0.1 -0.1 -0.1 -0.0 -0.0 -0.0 F4GOU +4.0 +4.0 +4.3 +3.9 +3.6 +3.6 +3.9 +3.9 +3.5 +4.0 F4VVG -0.1 +0.1 -0.2 -0.3 -0.2 -0.0 -0.1 -0.1 +0.0 -0.1 F6IIT -0.8 -0.6 -0.8 -1.0 -1.4 -0.9 -1.6 -0.8 -0.7 -0.6 F6KGL +0.2 +0.3 +0.2 +0.2 +0.3 +0.0 +0.1 F8DGY -0.9 -0.7 -0.7 -0.9 -1.0 -0.7 -0.6 -0.7 -0.6 F8UKP -0.6 -1.6 -1.7 -1.8 -1.6 -1.6 -1.6 G0KTN +0.1 -0.0 +0.0 -0.0 +0.0 +0.1 -0.0 +0.0 +0.0 +0.1 G0TMX -0.5 -0.0 G3XBI +0.3 +0.4 +0.0 +0.2 +0.2 +0.3 +0.3 +0.3 +0.5 +0.3 G3YPP +0.0 +0.1 +0.0 +0.1 G4AON +0.6 +1.0 +1.1 G4FRE +1.2 +1.1 G4HSO +0.3 -0.5 +0.0 +0.1 -0.1 -0.0 -0.0 +9.0 -0.3 -0.3 G4IRN +0.0 -0.0 +0.2 +0.1 +0.3 +0.4 +0.4 +0.2 +0.2 +0.3 G4ZFE +0.1 +0.2 +0.2 -0.0 -0.1 -0.0 -0.1 +0.0 -0.0 -0.0 GI4DOH -0.1 -0.1 +0.2 +0.0 +0.3 +0.3 +0.2 GSWL1 +2.8 HA1VHF -3.1 -3.2 -3.0 -2.8 -2.8 -2.7 -3.2 -2.7 -2.4 -1.9 HA5PP +4.6 HA6PX -0.1 -0.1 +0.0 -0.0 -0.1 -0.1 -0.1 -0.0 -0.1 -0.0 HA8TKS +0.1 +0.0 +0.1 +0.1 +0.1 +0.1 +0.1 +0.1 +0.2 +0.1 HB9BXE +0.0 +0.1 +0.3 +0.3 +0.2 +0.1 +0.2 +0.2 +0.3 +0.1 HB9DCO -0.5 -0.4 -0.4 -0.5 -0.6 -0.5 -0.4 -0.4 -0.4 -0.3 HG0Y +7.1 +6.2 +6.3 +6.3 +6.6 +6.7 HG8A -0.6 -0.1 -0.1 -1.8 -1.3 +0.1 -0.7 -0.5 -0.0 -0.5 IK3STG +3.8 +3.4 +3.3 +3.4 +3.4 +3.4 +3.0 +3.3 +2.8 +2.5 IK4VET +0.9 +0.8 +0.7 +0.6 +0.9 +0.9 +1.4 +1.1 +1.0 +1.3 IZ2CPS -0.6 -0.5 -1.1 -0.9 -0.7 -0.6 -0.3 J68HZ +16.5 JG1DLY -0.4 JH4UTP +0.0 JH7CSU1 +1.5 +1.5 +1.4 +1.3 +1.3 +1.3 +1.8 JI1HFJ -1.5 -4.3 +1.0 -1.1 -3.5 -8.5 -2.4 -5.1 -2.0 -2.5 JJ2VLY -0.8 -0.3 +1.0 +0.7 +0.8 +0.5 +0.3 -1.7 +1.9 +1.5 JK1QLQ +0.0 -0.2 +0.0 +0.1 +0.0 -0.3 +0.0 +0.4 +0.0 -0.3 JN1ILK -2.4 -1.1 +0.1 -0.1 -0.6 -0.5 +0.0 -0.2 -0.3 -0.0 K1RA +0.0 -0.1 -0.1 -0.4 -0.8 -0.5 -0.3 -0.8 -0.4 -0.2 K2PO/7 +0.2 +0.2 +0.3 +0.2 +0.3 +0.5 +0.4 +0.2 +0.4 +0.5 K3LR +0.6 +0.9 +0.6 +1.0 +1.1 +0.7 +0.4 +0.4 +0.5 +0.4 K3PA-1 -0.0 -0.0 -0.1 +0.1 +0.0 +0.1 +0.1 -0.1 +0.0 +0.1 K3PA-2 -1.4 -1.0 -0.8 -0.8 -1.7 -0.9 -1.0 K4PP -0.0 +0.1 -0.1 -0.2 -0.4 -0.3 -0.3 -0.4 +0.0 +0.2 K5EM -0.4 -0.2 +0.1 +0.0 +0.1 +0.0 -0.1 +1.8 K5TR +0.3 +0.3 +0.2 +0.3 +0.2 +0.2 +0.2 +0.3 +0.2 K6FOD -0.1 -0.1 +0.0 -0.1 -0.1 +0.1 +0.1 +0.1 +0.1 -0.0 K7CO +0.2 +0.0 +0.2 +0.0 +0.1 +0.5 +0.5 +0.1 +0.5 +1.3 K7EK +0.1 +0.0 +0.0 +0.0 +0.2 +0.3 +0.2 -0.0 +0.3 +0.1 K7MJG +0.1 +0.0 -0.2 +0.0 +0.0 +0.1 +0.2 +0.1 +0.0 -0.1 K9IMM -0.0 -0.0 -0.0 -0.1 -0.1 +0.0 +0.0 -0.1 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-2.5 -3.3 -3.5 -3.8 -3.5 -3.7 -3.7 -3.4 Last updated 2024-11-21 00:15:53 UTC
Anchor skimmers
The below skimmers use external frequency references and are confirmed to have continuous, high accuracy. Their accuracy is also confirmed against each other on a daily basis.
DF7GB ES2RR KM3T LZ3CB LZ4UX MM3NDH OE9GHV WB6BEE Last updated 2024-11-21 00:15:53 UTC
It is the owners of these skimmers who make this web page possible. Thank you.
To get good geographic coverage and a good size dataset, a two-step method is used for the analysis shown above. Since the second step also relies on spots from skimmers with slightly lower accuracy the displayed error for the anchor skimmers may not always be 0.0, even though they are perfectly accurate.
Software
The software powering this page can be found on github.