High ionospheric activity effects on LatPos RTK network performance in Latvia

The Near Real Time Ionospheric Model of Latvia

A highly accurate ionosphere model is necessary to enable a fast and reliable coordinate determination with GNSS in real time. It is a partially ionized atmospheric region ranging up to 1,000 km height, affected by spatial variations, space weather, seasonal and solar cycle dependence. New approaches and algorithms of modelling techniques are sought to provide better solutions in the territory of Latvia. Ionospheric TEC value has large differences in Western Latvia and Eastern Latvia. Actual ionospheric map should be calculated and delivered to the surveyors near real time and published on the WEB. Delivering actual map to rover GNSS devices in a field will provide the surveyors with ionosp…

Field tests of astrometric subsystem

The paper presents results of astrometric subsystem’s functionality tests for space object laser ranging and astrometric position determination device, which is under construction in the Institute of Geodesy and Geoinformatics (GGI) of the University of Latvia. Properties of hardware performance for astrometric image acquisition were evaluated and optimal parameters have been selected. Software for image processing and calculation of instrument orientation was tested and adjustments have been made for real-time operation support. Object tracking properties were evaluated, and mount error model parameters were calculated, using test measurements.

Development of the One Centimeter Accuracy Geoid Model of Latvia for GNSS Measurements

There is an urgent necessity for a highly accurate and reliable geoid model to enable prompt determination of normal height with the use of GNSS coordinate determination due to the high precision requirements in geodesy, building and high precision road construction development. Additionally, the Latvian height system is in the process of transition from BAS- 77 (Baltic Height System) to EVRS2007 system. The accuracy of the geoid model must approach the precision of about ~1 cm looking forward to the Baltic Rail and other big projects. The use of all the available and verified data sources is planned, including the use of enlarged set of GNSS/levelling data, gravimetric measurement data and…

IK "HOLS" attīstības stratēģija

Tā kā gan valsts, gan starptautiskā līmenī nepārtraukti notiek straujas un bieži vien pretrunīgas izmaiņas, tad, lai tām pielāgotos vai tās izmantotu, uzņēmumam jāanalizē šo pārmaiņu ietekme uz tā saimniecisko darbību un nepārtraukti jāattīstās. Darba mērķis: izstrādāt individuālā komersanta „Hols” attīstības stratēģiju, pamatojoties uz uzņēmējdarbības iekšējās un ārējās vides analīzi. Bakalaura darba rezultātā noskaidrots, ka pēdējos gados uzņēmējdarbības ārējā vide, ir īpaši ekonomiskā vide, ir negatīvi ietekmējusi IK „Hols” tirgus pozīcijas, uzņēmuma finansiālo situāciju un konkurētspēju kravu autopārvadājumu nozarē. Darbs satur 61 lapas, 1 tabula, 21 attēlu un 28 bibliogrāfiskos nosauku…