Changeset 11205 in ntrip for trunk/BNC/src/bnchelp.html

Timestamp:

Nov 13, 2026, 6:46:33 PM (45 hours ago)

Author:

stuerze

Message:

kalman filter combination improved

File:

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

trunk/BNC/src/bnchelp.html

@@ -8323 +8323 @@
     <tr>
       <td>&nbsp; AC_Offset </td>
-      <td>&nbsp; &nbsp; AC specific offset</td>
+      <td>&nbsp; &nbsp; AC specific offset per GNSS (clock datum of the AC)</td>
     </tr>
     <tr>
       <td>&nbsp; Sat_Offset</td>
-      <td>&nbsp; &nbsp; Satellite specific offset common to all ACs</td>
+      <td>&nbsp; &nbsp; Offset of the AC for a satellite (e.g. different realizations of the code biases)</td>
     </tr>
     <tr>
@@ -8335 +8335 @@
   </table>
   </p>
-  These three parameter types differ in their statistical properties. The satellite clock offsets are assumed to be
-  static parameters
-  while AC specific and satellite specific offsets are stochastic parameters affected by white noise.
-  The solution is regularized by a set of minimal constraints. In case of a change of the 'SSR Provider ID',
+  These three parameter types differ in their statistical properties: the AC specific offsets and the combined clocks
+  are estimated anew every epoch (white noise), the satellite specific offsets are random walk parameters (1 cm per
+  10 seconds). The solution is regularized by minimal constraints: per epoch the combined clocks sum up to zero, the
+  satellite specific offsets of all ACs providing a satellite sum up to zero, and the satellite specific offsets of
+  each AC sum up to zero. The last condition makes the AC specific offset the mean clock difference of the AC; without
+  it, the combined clock of a satellite not provided by all ACs would depend on the history of the filter (e.g. after a
+  restart). In case of a change of the 'SSR Provider ID',
   'SSR Solution ID', or 'IOD SSR' (see section 'Upload Corrections'), the satellite clock offsets belonging to the
   corresponding analysis center are reset in the adjustment.