N.S. Kulichkova – Design Engineer, JSC «SPE «Radiosvyaz» (Krasnoyarsk); Post-graduate Student, Siberian Federal University (Krasnoyarsk)
K.A. Kulichkov – Design Engineer, JSC «SPE «Radiosvyaz» (Krasnoyarsk); Post-graduate Student, Siberian Federal University (Krasnoyarsk)
A.V. Grebennikov – Ph.D. (Eng.), Associate Professor, Head of the Basic Department «Radioelectronic Equipment of Information Systems», Siberian Federal University (Krasnoyarsk); Head of Sector, JSC «SPE «Radiosvyaz» (Krasnoyarsk)
The main basic determining error the measurement coordinates of global navigation satellite systems (GNSS) is the error in measuring distance between navigation satellite and navigation equipment consumer. Directly estimated is not the real distance, аnd distance measured unrequested way (unrequested range). Among the sources of error are ionospheric, tropospheric, multipath, and instrumental errors.
In addition to the listed basic errors there is a delay source of which is antennas, cables, as well various filters used in receivers and satellites. This delay is called instrumental. Instrumental delay has an impact on both measurement coda, both on measurement carrier. For navigation equipment consumer satellite GPS transmit in their navigation messages total group delay (TGD). Also data TGD are provided analytical centers IGS along with files Global Ionospheric Maps.
Received experimental data show, that use of TGD reduce standard deviation error determine coordinates approximately in 2,5 times, but there is a displacement mean value approximately in 0,4 meter of the true value.
Despite the displacement mean value from true, improvement error, determine coordinates gives significant reduce standard deviation error, but the application TGD to navigation satellites GLONASS is impossible. Relying on this fact, was offered way calculating instrumental delay for use in determine coordinates by signal GLONASS.
For getting instrumental delay, it is necessary to measurement unrequested range through navigation equipment consumer within a day.
Way is based on the installation of an antenna module navigation equipment consumer at point with known coordinates, and connection hydrogen frequency and tame to navigation equipment consumer. Such connection gives possibility settle true value range from navigation equipment consumer to navigation satellite and comparing true value with the measured, get error determine unrequested range. Point with known coordinates should be in place with the least number of re-reflective objects that reduce influence multipath on measurements. Get error unrequested range is necessary take account ionospheric and tropospheric errors, and also take into account detuning scale time navigation equipment consumer from the scale navigation satellite.
Applying correction basic errors and having received value error determine unrequested range you can get a calibration table for cor-rection of measurements. Using table suffer reduce standard deviation error determine coordinates in 2,5 times.
- Matsakis, Demetrios The Timing Group Delay (TGD) Correction and GPS Timing Biases // Proceedings of the 63rd Annual Meeting of The Institute of Navigation (2007). Cambridge, MA. April 2007. P. 49–54.
- Kulichkova N.S., Kulichkov K.A., Grebennikov A.V. Issledovanie varianta realizacii metoda korrekcii ionosfernoj pogreshnosti global'noj navigacionnoj sputnikovoj sistemy po fazovym izmereniyam v razlichnyh chastotnyh diapazonah // Uspehi sovremennoj radioelektroniki. 2017. № 12. S. 53–57.