The Baltic Sea Chart Datum 2000 (BSCD2000): Implementation of a common reference level in the Baltic Sea

The Baltic Sea Chart Datum 2000 (BSCD2000) is a geodetic reference system adopted for Baltic Sea hydrographic surveying, hydrographic engineering, nautical charts, navigational publications and water level information. It is based on the common geodetic standards for the height system (EVRS) and the spatial reference system (ETRS89) in Europe. In particular, the zero level of BSCD2000 is in accordance with the Normaal Amsterdams Peil (NAP). BSCD2000 is about to be adopted as unified chart datum by all the countries around the Baltic Sea. It agrees with most national height realizations used on land. BSCD2000 will facilitate effective use of GNSS methods like GPS, GLONASS and Galileo for accurate navigation and hydrographic surveying in the future.El Dátum 2000 de la Carta del Mar Báltico (BSCD2000) es un sistema dereferencia geodésico adoptado para los levantamientos hidrográficos del MarBáltico, la ingeniería hidrográfica, las cartas náuticas, las publicaciones náuticas yla información sobre el nivel del mar. Se basa en las normas geodésicas comunespara el sistema de alturas (EVRS) y en el sistema de referencias espaciales(ETRS89) en Europa. En particular, el nivel cero del BSCD2000 está en consonanciacon el Normaal Amsterdams Peil (NAP). El BSCD2000 está a punto de seradoptado como datum de cartas unificado por todos los países que rodean el MarBáltico. Concuerda con la mayoría de las realizaciones de alturas nacionalesutilizadas en tierra. El BSCD2000 facilitará el uso efectivo de los métodos GNSScomo el GPS, GLONASS y Galileo para la navegación precisa y los levantamientoshidrográficos en el futuro.Le Baltic Sea Chart Datum 2000 (BSCD2000) est un système de référencegéodésique adopté pour les levés hydrographiques, l’ingénierie hydrographique,les cartes marines, les publications nautiques et les informations sur le niveau del’eau de la mer Baltique. Il est basé sur les normes géodésiques communes auSystème de Référence Vertical Européen (EVRS) et au Système de RéférenceTerrestre Européen (ETRS89). En particulier, le zéro hydrographique duBSCD2000 est conforme au Normaal Amsterdams Peil (NAP). Le BSCD2000 estsur le point d’être adopté en tant que niveau de référence des cartes commun parl’ensemble des pays bordant la mer Baltique. Il correspond à la plupart desmesures de hauteur nationales utilisées à terre. Le BSCD2000 facilitera l’utilisationefficace des méthodes du GNSS comme le GPS, GLONASS et Galileo pour unenavigation et des levés hydrographiques précis à l’avenir

Improving the Geodetic Infrastructure for Bathymetry and 3D Navigation in the German Exclusive Economic Zone of the North and Baltic Sea

Surveying and navigation became much easier, more accurate and operational thanks to the Global Positioning System. The use of this technology in height determination, bathymetry and 3-D navigation is not only limited by the reduced accuracy compared to the horizontal component. It supposes additional information about the geodetic height reference surface in order to leverage the full potential of this technology. The corresponding models, measurements and activities which are necessary to improve this part of the geodetic infrastructure are usually behind the curtain. This article emphasizes the need of a common cross-border geodetic infrastructure and the relevance of precise models of the height reference surface for GNSS-aided height determinations. The need of gravimetric surveys for the determination and improvement of these models is explained. Finally, it gives an overview about the gravimetric surveys which were carried out in the German Exclusive Zone of the North and Baltic Sea over more than one decade and provides some insight into practical aspects and challenges of this kind of surveys.En un proyecto de dos años de investigación y desarrollo, se desarrolló el prototipo de un servicio en tiempo real basado en GNSS (Sistema Global de Navegación por Satélite) usando un enfoque SSR-RTK (Cinemática en Tiempo Real – Representación del Espacio Nacional) para la zona económica exclusiva alemana en el Mar del Norte. Como el área de levantamientos del Mar del Norte solo se puede representar mediante una distribución heterogénea de Estaciones de Referencia GNSS en Funcionamiento Constante, el algoritmo de cálculo y el modelado de los datos de corrección del GNSS son particularmente importantes. Las mediciones marítimas en el área de levantamientos han confirmado la funcionalidad básica del prototipo hasta casi el 90% de disponibilidad de la determinación de estado RTK con tiempos de inicialización de menos de dos minutos. Se usaron mediciones en tierra y mar además de una estación de control permanente para demostrar los objetivos de calidad.Dans le cadre d’un projet de recherche et développement de deux ans, le prototype d’un service en temps réel basé sur un GNSS (Global Navigation Satellite System) utilisant une approche SSR-RTK (State Space Representation-Real Time Kinema-tic) a été développé pour la zone économique exclusive allemande en mer du Nord. Étant donné que la zone d’étude de la mer du Nord ne peut être représentée qu’avec une distribution hétérogène des stations de référence GNSS en exploitation continue, l’algorithme de calcul et la modélisation des données de correction GNSS sont particulièrement importants. Les mesures à la mer dans la zone d’étude ont confirmé la fonctionnalité de base du prototype grâce à une disponibilité de près de 90% du correctif RTK avec des temps d’initialisation inférieurs à deux minutes. Des mesures en mer et à terre ainsi qu’une station de contrôle permanente ont été utili-sées pour démontrer les objectifs de qualité

Quantification of Baltic sea water budget components using dynamic topography

Accurate quantification of the Baltic Sea's dynamics and water budget components is essential for understanding both seasonal and long-term variations influenced by climate change. In this study, we utilize dynamic topography (DT), referenced to a geoid-based chart datum, to derive dynamic water volume and to improve estimates of the main water balance components, such as river runoff and water exchange through the Danish Straits. We utilize DT for the period from 2017 to mid-2021, which was corrected for vertical sea level biases and whose vertical datum thus coincides with the geoid. Our findings reveal seasonal dynamic volume variations, with a minimum in spring (78.9 ± 60 km3) and a maximum in autumn and winter (121 ± 57 and 124 ± 80 km3, respectively). Anomalies in DT highlight a specific region (northern Baltic Proper) as representing equilibrium mean DT for the entire Baltic Sea, while areas in the eastern and southern Baltic are prone to extremes. Barotropic exchange analysis shows that no major Baltic inflows occurred during the study period, with small to medium inflows averaging 1.6 km3 d−1 in autumn and winter, while outflows averaged 2.36 km3 d−1. River discharge, indirectly calculated from the water budget, peaked in summer (2.08 km3 d−1) and was lowest in autumn (1.26 km3 d−1), with hydrological models underestimating flows in these seasons. As a result, the method and results show great potential for quantification, validation, and a better understanding of the dynamics of the Baltic Sea, especially with a changing climate.</p

Journal of Applied Hydrography

Fokusthema: Habitatkartierun

Satellite Remote Sensing Signatures of the Major Baltic Inflows

Variability of sea level in the North and Baltic Seas, enforced by weather patterns, a ects the intensity of water exchange between these seas. Transfer of salty water from the North Sea is very important for the hydrography of the Baltic Sea. The volume of inflowing salty water can occasionally increase remarkably. Such incidents, called the Major Baltic Inflows (MBIs), are unpredictable, of relatively short duration, and di cult to observe using in situ data. We have shown that remote sensing altimetry can be used as a complementary source of information about the MBI events. The advantage of using such data is that large-scale spatial information about SLA is available with daily resolution. We have described changes in SLA during several MBI events observed in 1993–2017. The net volume of water transported into the Baltic Sea varied between the events due to di erences in atmospheric forcing. Based on SLA data, the largest inflow of water happened during the 2014 MBI. This is in agreement with previously published results, based on in situ data

Assessment of marine geoid models by ship-borne GNSS profiles

Even though the entire Baltic Sea is included in previous geoid modelling projects such as the NKG2015 and EGG07, the accuracy of contemporary geoid models over marine areas remains unknown, presumably being offshore around 15–20 cm. An important part of the international cooperation project FAMOS (Finalising Surveys for the Baltic Motorways of the Sea) efforts is conducting new marine gravity observations for improving gravimetric quasigeoid modelling. New data is essential to the project as the existing gravimetric data over some regions of the Baltic Sea may be inaccurate and insufficiently scarce for the purpose of 5 cm accuracy geoid modelling. Therefore, it is important to evaluate geoid modelling outcome by independent data, for instance by shipborne GNSS measurements. Accordingly, this study presents results of the ship-borne marine gravity and GNSS campaign held on board the Estonian Maritime Administration survey vessel “Jakob Prei” in West-Estonian archipelago in June/July 2016. Emphasis of the study is on principles of using the GNSS profiles for validation of existing geoid models, post-processing of GNSS raw data and low-pass filtering of the GNSS results. Improvements in geoid modelling using new gravimetric data are also discussed. For example, accuracy of geoid models including the new marine gravity data increased 11 mm as assessed from GNSS profiles. It is concluded that the marine GNSS profiles have a potential in providing complementary constraints in problematic geoid modelling areas

Kodlista och processbeskrivning för inmätning med maskinstyrning

Huvudsyftet med detta examensarbete var att utveckla en processbeskrivning och en kodlista för inmätning av punkter med maskinstyrning. Ett delsyfte var att reda ut vilka benämningssystem som redan finns och används. Arbetet har gjorts åt Sjöblom Infra Ab som är ett växande företag inom infrabyggande, industriservice och återvinning. Teoridelen beskriver vad maskinstyrning är och hur det fungerar. Det behandlar också höjdsystem, koordinatsystem och positionering som är viktiga faktorer för ett fungerande maskinstyrningssystem. Benämningssystem som redan finns och används behandlas också i teoridelen. Frågeformulär skickades ut till företag som säljer maskinstyrning och till företag som säljer mätningstjänster. Tanken med frågeformulären var att få svar på vad de använder för benämningssystem och om det finns något standardiserat benämningssystem. Resultatet blev en kodlista och en processbeskrivning för inmätning av punkter med maskinstyrning enligt företagets önskemål. Kodlistan innehåller 28 koder som bedömdes vara de mest användbara koderna för företagets infrabyggnadsprojekt. Processbeskrivningen beskriver hur olika konstruktioner skall mätas in, var och med vilket avstånd.Tämän opinnäytetyön päätavoitteena oli kehittää prosessikuvaus ja koodilista mittauspisteiden mittaamiseen koneohjauksella. Osatavoitteena oli selvittää, mitä nimeämisjärjestelmiä on jo olemassa ja käytössä. Työ tehtiin Sjöblom Infra Ab:lle, joka on kasvava yritys infrarakentamisessa, teollisuuspalveluissa ja kierrätyksessä. Teoriaosuudessa kuvataan, mitä koneohjaus on ja miten se toimii. Siinä käsitellään myös korkeusjärjestelmiä, koordinaattijärjestelmiä ja paikannusta, jotka ovat tärkeitä tekijöitä toimivan koneohjausjärjestelmän kannalta. Teoriaosuudessa käsiteltiin myös jo olemassa olevia ja käytössä olevia nimitysjärjestelmiä. Kyselylomakkeet lähetettiin koneohjausta myyville yrityksille ja maanmittauspalveluja myyville yrityksille. Kyselylomakkeiden tarkoituksena oli selvittää, millaisia nimitysjärjestelmiä ne käyttävät ja onko olemassa standardoitua nimitysjärjestelmää. Tuloksena saatiin yrityksen toiveiden mukainen koodiluettelo ja prosessikuvaus pisteiden mittaamiseksi koneohjauksella. Koodiluettelossa on 28 koodia, joita pidettiin hyödyllisimpinä koodeina yrityksen infrastruktuurin rakentamishankkeessa. Prosessikuvauksessa kuvataan, miten eri rakenteita mitataan, missä ja millä etäisyydellä.The main purpose of this thesis is to develop a process description and a code list for surveying points whit machine control. A sub-purpose was to clarify which nomenclature already exist and is used. The work was done for Sjoblom Infra Ab, which is a growing company in infrastructure construction, industrial services and recycling. The theoretical part describes what machine control is and how it works. It also covers height systems, coordinate systems and positioning which are important factors for a functioning machine control system. Nomenclatures that already exist and are used were also dealt with in the theoretical part. Questionnaires were sent out to companies that sell machine control and to companies that sell surveying services. The idea behind the questionnaires was to get answers on what nomenclature they use and if there is any standardized nomenclature. The result was a code list and a process description for surveying points whit machine control according to the company’s requirements. The code list contains 28 codes that were assessed to be the most useful code for the company’s infrastructure projects. The process description explains how different constructions should be surveyed, where and at what distance