Changeset 11100 in ntrip

Timestamp:

Oct 19, 2026, 10:31:32 AM (4 hours ago)

Author:

stuerze

Message:

minor changeshelp contents updated

File:

• trunk/BNC/src/bnchelp.html (modified) (2 diffs)

trunk/BNC/src/bnchelp.html

@@ -8214 +8214 @@
     is counted for the minimum of 2 ACs per satellite. A satellite observed by excluded ACs only is combined with
     the zero-sum condition of all its ACs as before, and if no consistent AC provides corrections for a system, the
-    exclusion is not applied. The checks continue: as soon as a check finds no inconsistency any more (or B_IF no
-    longer varies noticeably between the satellites, e.g. after the provider has aligned its biases), the AC is
-    used for the clock datum again, which is reported in both logfiles. A smaller weight factor of the AC would not
+    exclusion is not applied. The checks continue: once 12 checks in a row (1 hour) find no inconsistency any more
+    (or B_IF no longer varies noticeably between the satellites, e.g. after the provider has aligned its biases), the
+    AC is used for the clock datum again, which is reported in both logfiles. A single passing check is not
+    sufficient, because the offsets are reset with the exclusion and not yet converged; a borderline AC would
+    otherwise change the clock datum every few minutes. A smaller weight factor of the AC would not
     help instead: the weights act on the epoch-wise clock variations, while the satellite-specific constant part is
     fixed by the zero-sum conditions, independent of the weights.
@@ -8512 +8514 @@
     combined without it at the latest when the newest incoming corrections are 10 seconds (or the sampling interval,
     if larger) younger than the epoch. Corrections arriving after an epoch was combined are ignored.</p>
+  <p>
+    The satellite-specific offsets of the ACs in the Kalman filter are modelled as a random walk of 1 cm per 10
+    seconds, independent of the sampling interval, so that 5 and 10 seconds give comparable offsets. The combined
+    satellite clocks themselves are estimated epoch by epoch.</p>
 
   <p>