Latest GNSS Viewer 20170712 version has Cycle Slip Count added. It relates to signal quality seen by the receiver, showing how many satellite signals has cycle slip detected when in Float RTK and Fix RTK state. Two cycle slip numbers are shown, left for the rover, right for the base.
Below video shows low cycle slip count situation, mostly zero occasionally one, it gets RTK Fix quickly.
Below video shows high cycle slip count situation, unable to get RTK Fix, also the signal is strangely fluctuating.
Sometime when unable to get RTK Fix, this cycle slip count can help reveal the cause. It can be antenna quality related or interference related.
Generally using antenna that gives strong stable signal with occasional cycle slip count no larger than 3 will provide good RTK performance with faster RTK Fix; lower the cycle slip count the better.
20170712 firmware update has this cycle slip count feature added, to be used with the new 20170712 GNSS Viewer.
Single frequency RTK receivers work well under open sky environment. But when tall buildings or trees are encountered, none has yet shown to work well, they lose RTK Fix and have position jumps. This $595 Multi-Band, Multi-Constellation RTK GNSS Receiver struggles too when near trees.Below video shows our soon to be released firmware update that could [...]
-S version having RTK position stamp feature is mainly for UAV mapping application. It takes external positive edge camera trigger signal occurring on the TRIG pin and compute RTK position within closest internal 1msec tic and output in STI,005 message. For 50Km/hr flying UAV, max position error is 50e5/3600/1000 = 1.39cm on top of 1cm [...]
Below shows test result of NS-HP-GL GPS/GLONASS RTK receiver.Short Baseline 15 Hour Testing Accuracy: CEP 50% 0.33cm, R95 0.69cm, SEP 50% 0.63cm.Short Baseline Recycle Power Time to RTK Fix Testing, 75 TrialsAverage time to RTK Fix 23 sec.Longer Baseline Time to RTK Fix Testing, 5 Trials Each.11Km Baseline Drive Test Using Survey Grade HX-CSX601A Antenna and Tallysman TW2710 [...]
GPS receiver output correct course over ground (COG) information when in motion. It represent movement direction. Without movement, the output COG information may be incorrect.Some applications, such as marine vessel autopilot, require knowledge of accurate heading direction regardless of movement direction. NS-HP-GL configured in moving base RTK mode gives precise heading in the direction [...]
NS-HP or NS-HP-GL are single frequency RTK receivers. For reliable consistent single-frequency RTK operation, they require 12 or more usable satellite signals above 15 degree elevation angle with SNR no less than 38dB/Hz. With 10 or 11 usable satellite signals, we've seen less than 0.1% rate of getting incorrect RTK Fix off by centimeters ~ decimeters. [...]