<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif;font-size:10px"><div id="yui_3_16_0_ym19_1_1466595974981_3115">Hello,</div><div id="yui_3_16_0_ym19_1_1466595974981_3115"><br></div><div id="yui_3_16_0_ym19_1_1466595974981_3115" dir="ltr">I am doing Kinematic between base (LLH = 44.434828231 12.300198659 45.9096) and rover.</div><div id="yui_3_16_0_ym19_1_1466595974981_3115" dir="ltr">The rover has 4Hz.</div><div id="yui_3_16_0_ym19_1_1466595974981_3115" dir="ltr">The base has normally 0.2 Hz rate, but across midnight experiences a gap of about 90 seconds.</div><div id="yui_3_16_0_ym19_1_1466595974981_3115" dir="ltr">So the age of differential correctly grows and solution goes from 1 (fix) to 5 (single).</div><div id="yui_3_16_0_ym19_1_1466595974981_3115" dir="ltr">However when the base eventually comes back, a perfectly good set of observations pushes the EKF so far that AR does not recover anymore.</div><div id="yui_3_16_0_ym19_1_1466595974981_3115" dir="ltr">So far I am solving this by adding </div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3440"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3440"><font face="Courier New, courier, monaco, monospace, sans-serif" id="yui_3_16_0_ym19_1_1466595974981_4075"> memset(rtk->x, 0, rtk->nx*sizeof(double)); /** RESET FLOAT STATES?? */</font></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441">in <i id="yui_3_16_0_ym19_1_1466595974981_3762">rtkpos.c</i> after </div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3482"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3482"><font face="Courier New, courier, monaco, monospace, sans-serif" id="yui_3_16_0_ym19_1_1466595974981_4051"> errmsg(rtk,"age of differential error (age=%.1f)\n",rtk->sol.age);</font></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441">However, my fix looks dirty and the problem should not manifest in the first place?</div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441">So far I am guessing the problem is here:</div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441"><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3710"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3710"><font face="Courier New, courier, monaco, monospace, sans-serif" id="yui_3_16_0_ym19_1_1466595974981_4050"> if ((nv=ddres(rtk,nav,dt,xp,Pp,sat,y,e,azel,iu,ir,ns,v,H,R,vflg))<1) {</font></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3711"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3711">inside <font face="Courier New, courier, monaco, monospace, sans-serif">relpos() </font>in <i id="yui_3_16_0_ym19_1_1466595974981_4049">rtkpos.c</i>. </div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3711">My feeling is that the age of correction when the base wakes up is said to be 0.2 seconds when in reality more than 90 have passed and so the partial derivatives go off scale?</div></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3929">Such behavior, if confirmed, may impair any real-life situation in which base and rover talk unreliably between each other...<br id="yui_3_16_0_ym19_1_1466595974981_3930"></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3931"></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441">All data are here:</div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441"><a href="https://www.dropbox.com/s/igwt9jsh8pco1bs/160531n-aann.zip?dl=0" id="yui_3_16_0_ym19_1_1466595974981_3556">https://www.dropbox.com/s/igwt9jsh8pco1bs/160531n-aann.zip?dl=0</a><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441">Can anybody comment on this and propose a cleaner fix?<br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441"><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3906"><br id="yui_3_16_0_ym19_1_1466595974981_3907"></div></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441">Cheers,</div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441">Michele</div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1466595974981_3441">P.S.: This happens with both 2.4.2b11 and 2.4.3b12</div></div></body></html>