Global Monitoring for Environment and Security (GMES) is the European programme to establish a European capacity for Earth Observation. GMES is designed to provide European policy makers and public ...authorities with accurate and timely information to better manage the environment, understand and mitigate the effects of climate change and ensure civil security. Sentinel-3 is an Earth observation satellite mission specifically designed for GMES to ensure the long-term collection and operational delivery of high-quality measurements to GMES ocean, land, and atmospheric services, while contributing to the GMES, emergency and security services. Key Sentinel-3 measurement requirements, corresponding to identified GMES user needs, have been derived as follows:•Sea surface topography (SSH), significant wave height (Hs) and surface wind speed derived over the global ocean to an equivalent accuracy and precision as that presently achieved by ENVISAT Radar Altimeter-2 (RA-2) but with enhanced surface topography measurements in the coastal zone, sea ice regions and over inland rivers, their tributaries and lakes.•Sea surface temperature (SST) determined for oceanic and coastal waters globally to an equivalent accuracy and precision as that presently achieved by the ENVISAT Advanced Along Track Scanning Radiometer (AATSR) over the ocean (i.e. <0.3K), at a spatial resolution of 1km.•Visible, and Short-Wave Infrared radiances for oceanic, inland and coastal waters at a spatial resolution of 0.3km (simultaneously and co-registered with SST measurements), determined to an equivalent level of accuracy and precision as ENVISAT Medium Resolution Imaging Spectrometer with complete ocean coverage in 2–3days.•Visible and infrared radiances over global land-surfaces in 1–2days, sea-ice and ice-sheets equivalent to those currently provided from ENVISAT MERIS, AATSR and Système Probatoire d'Observation de la Terre (SPOT) Vegetation.
The Sentinel-3 mission addresses these requirements by implementing and operating:•A dual frequency, Synthetic Aperture Radar Altimeter (SRAL) instrument supported by a dual frequency passive microwave radiometer (MWR) for wet-tropospheric correction, a Precise Orbit Determination package including a GPS receiver, a DORIS instrument and a laser retro-reflector.•A highly sensitive Ocean and Land Colour Imager (OLCI) delivering multi-channel wide-swath optical measurements for ocean and land surfaces.•A dual-view Sea and Land Surface Temperature Radiometer (SLSTR) delivering accurate surface ocean, land, and ice temperature.•A collaborative ground segment providing management of the mission, management, development, production and access to core data products in an operational near real time delivery context.
The mission foresees a series of satellites, each having 7-year lifetime, over a 20-year period starting with the launch of Sentinel-3A in late 2013 and of Sentinel-3B in late 2014. During full operations two identical satellites will be maintained in the same orbit with a phase delay of 180°.
This paper provides an overview of the GMES Sentinel-3 mission including the mission background and user requirements, a technical description of the space segment, a brief overview of the ground segment concept, and a summary description of Sentinel-3 data products and their anticipated performance.
► A new satellite mission called Sentinel-3 dedicated to oceanography is described. ► A technical overview of the Sentinel-3 instrument payload is presented. ► A summary of the Sentinel-3 ground segment and operations concept is presented. ► A summary of products derived from Sentinel-3 payload instruments is presented.
Initially developed for monitoring the performance of TOPEX/Poseidon and follow-on Jason legacy satellite altimeters, the Corsica geodetic facilities that are located both at Senetosa Cape and near ...Ajaccio have been developed to calibrate successive satellite altimeters in an absolute sense. Since 1998, the successful calibration process used to calibrate most of the oceanographic satellite altimeter missions has been regularly updated in terms of in situ instruments, geodetic measurements and methodologies. In this study, we present an assessment of the long-term stability of the in situ instruments in terms of sea level monitoring that include a careful monitoring of the geodetic datum. Based on this 20-yr series of sea level measurements, we present a review of the derived absolute Sea Surface Height (SSH) biases for the following altimetric missions based on the most recent reprocessing of their data set: TOPEX/Poseidon and Jason-1/2/3, Envisat and ERS-2, CryoSat-2, SARAL/AltiKa and Sentinel-3A&B. For the longest time series the standard error of the absolute SSH biases is now at a few millimeters level which is fundamental to maintain the high level of confidence that scientists have in the global mean sea level rise.
The CryoSat-2 satellite, primarily dedicated to precise monitoring of the Cryosphere, is demonstrating its capability to provide valuable altimetric data also over the ocean. Here we present the ...results of a global assessment and validation of the new Geophysical Ocean Product (GOP) distributed by the European Space Agency (ESA) since April 2014, focusing on the sea surface height anomaly (SSHA), the significant wave height (SWH), and the wind speed. Our assessment involves only Low Resolution Mode (LRM) and Pseudo LRM (PLRM) data, since full SAR processing is not already operationally implemented in the GOP. The global assessment is conducted on the basis of measurement noise and along-track spectral and crossover analysis, whereas the validation is performed against a variety of in situ observations such as tide gauges, buoys and Argo floats as well as data from the WaveWatch III (WWIII) model. The performance of the GOP is compared to that of Jason-2 and CryoSat-2 data from the Radar Altimeter Database System (RADS). The mean value of the 20-Hz SSHA noise at 2m SWH is 6.3cm for LRM and 10.2cm for PLRM, and the standard deviation of the crossovers is ~5.4cm. The mean 20-HZ SWH noise over the global oceans is 49.4cm and 69.8cm, for LRM and PLRM respectively. CryoSat-2 and Jason-2 show almost identical performance when SSHAs are validated against tide gauges, with a median correlation and root mean square difference (RMSD) of 0.78 and 7.1cm for the GOP, 0.76 and 7.3cm for Jason-2, and 0.79 and 7.8cm for CryoSat-2 from RADS. The median correlation with Argo-derived steric heights is 0.68 for the GOP, 0.74 for Jason-2, and 0.67 for CryoSat-2 from RADS. However, the correlation shows a strong latitudinal dependence, with higher values at low latitudes (median value larger than 0.80 in the 10°S-10°N band). The median RMSD between the SSHAs and steric heights is 5.3cm for the GOP, 4.6cm for Jason-2, and 5.1cm for CryoSat-2 from RADS. The GOP and Jason-2 show also identical performance when SWHs are compared to buoy data, with a slope and RMS error of 0.98 and 15cm for GOP, 0.97 and 16cm for Jason-2, and 1.05 and 17cm for CryoSat-2 from RADS. On the other hand, the GOP wind speed exhibits a bias of about 2m/s relative to both Jason-2 and to buoy data. Differences between the GOP and WWIII SWH are smaller than 20% of the SWH almost everywhere. In summary the GOP products are fit for oceanographic applications.
•New CryoSat-2 products are evaluated over the oceans.•Assessment includes noise and along-track spectral and crossover analysis.•Validation is performed against in situ observations and Jason-2.•Results show excellent performance of CryoSat-2.
Sentinel-1A is the first satellite of the European Copernicus programme. Equipped with a Synthetic Aperture Radar (SAR) instrument the satellite was launched on April 3, 2014. Operational since ...October 2014 the satellite delivers valuable data for more than two years. The orbit accuracy requirements are given as 5cm in 3D. In order to fulfill this stringent requirement the precise orbit determination (POD) is based on the dual-frequency GPS observations delivered by an eight-channel GPS receiver.
The Copernicus POD (CPOD) Service is in charge of providing the orbital and auxiliary products required by the PDGS (Payload Data Ground Segment). External orbit validation is regularly performed by comparing the CPOD Service orbits to orbit solutions provided by POD expert members of the Copernicus POD Quality Working Group (QWG). The orbit comparisons revealed systematic orbit offsets mainly in radial direction (approx. 3cm). Although no independent observation technique (e.g. DORIS, SLR) is available to validate the GPS-derived orbit solutions, comparisons between the different antenna phase center variations and different reduced-dynamic orbit determination approaches used in the various software packages helped to detect the cause of the systematic offset. An error in the given geometry information about the satellite has been found. After correction of the geometry the orbit validation shows a significant reduction of the radial offset to below 5mm. The 5cm orbit accuracy requirement in 3D is fulfilled according to the results of the orbit comparisons between the different orbit solutions from the QWG.
The SAR (Synthetic Aperture Radar) Copernicus Sentinel-1 satellites require a high orbit accuracy of 5 cm in 3D in comparison to external processing facilities. The official orbit products delivered ...by the Copernicus POD (Precise Orbit Determination) Service fulfil this requirement. Nevertheless, analyses have shown discrepancies in the orbit results for the two satellites Sentinel-1A and Sentinel-1B. Since the satellites are identical in construction estimated orbit parameters like the scale factor for the radiation pressure are expected to be at the same magnitude, which is not the case.
Estimation of GPS antenna offsets leads to differences between the two satellites, which might explain the discrepancies in the estimated orbit parameters. Such offset estimations are, however, very sensitive to orbit and observation modelling. It has to be assured that the results are not biased by insufficient models. First of all, stabilisation of the antenna offset estimation is achieved by improving the observation modelling by applying single receiver ambiguity resolution.
The Copernicus Sentinel-1 satellites have a very complex shape with the long SAR antenna and the two large solar arrays. Antenna offset estimation based on different satellite models may give results which differ by up to 1.5 cm. The dispersion of the estimates is quite large depending also on eclipse and non-eclipse periods. Consideration of simple assumptions on satellite self-shadowing effects improves the satellite model and also the results of the antenna offset estimation. Finally, more consistent results for the two Sentinel-1 satellites are achieved by applying the antenna offset estimates.
This paper investigates how societal goals of heritage conservation and energy efficiency are handled in the management of Swedish multi-residential buildings. Interviews were made with larger owners ...of multi-residential stocks, and their perspectives are compared to officials at the City Planning Offices in two Swedish municipalities: Göteborg and Gotland. The questions posed are: How is heritage prioritised in relation to increased energy efficiency, climate impact and other objectives such as cost-efficiency? How important are their internal policies in comparison with external policies imposed by society? The companies express that they are proud of the heritage of their building stock, but they have not integrated heritage values in their management plans and strategies. Social issues such as safety and well-being are included, but not heritage. A consequence of this lack of systematic consideration of heritage is that measures for increased energy efficiency may conflict with conservation needs. In order for heritage values to be taken more seriously in relation to energy efficiency they would need to be integrated into such plans. The benefit from integrating heritage values in sustainable housing management is a question that should be further studied. The paper refers to SDGs 3, 11 and 13.
The study reports from an on-going study of tenants' view on energy retrofit. The first results, which are based on 27 qualitative interviews show a generally positive attitude to energy saving and ...environmental protection. However, many tenants are not familiar with the link between energy use and energy retrofit, and the idea of energy saving might oppose to the actual willingness to contribute. One important lesson from these preliminary results is that the project owners have overlooked the importance of informing the tenants about the energy retrofit and what measures that are implemented. This leaves the tenants to their own interpretation of the matter and in some examples a negative image is created. In order to transition from the idea of personal benefit from energy retrofit to a larger responsibility and willingness to participate to society at large, we suggest that tenants are invited to discuss energy retrofit and that they are properly informed about implemented energy saving measures.
Abstract
The gap between energy policy and potential energy savings through renovation, and what is carried out in practice has been in focus of previous research. Various influencing factors such as ...economy, organisation, and social relations versus tenants has been studied to design guidelines to bridge this gap. There is a lack of empirical studies of how renovation is planned, and what factors will influence the renovation measures that are implemented. This paper takes the starting point in 42 on-going and planned housing renovation projects 2018 – 2021 carried out by three municipal housing companies in one major Swedish metropolitan area. Based on the character of these, three main types of housing renovation are defined. The most current type of renovation is bathroom and piping while climate envelope renovation and deep renovation are less common. Energy saving is decoupled from renovation activities which will have implications for implementation of policy for energy efficient renovation.
Introduction: The overall objective is to understand how policies may be used to increase the potential for saving energy while simultaneously preserving cultural values in the housing stock. The ...project contributes to SDGs 11, 17, 5, 8 and 10. Methods: The paper summarises and discusses findings in previous research and projects led by the authors. Finally the design of a new project launched in 2020 is presented. The purpose of Energy efficiency and cultural values. How well do the policies function on the local level? is to give valuable knowledge on how the building process, advice on energy use and renovation strategies work together in Swedish municipalities. Results: Since the 1970s there has been a conflict between the preservation of architectural heritage and decreasing energy use in the Swedish housing stock. The first policy programme focussing energy saving was launched after the first global energy crisis in 1973. Since then there have been different policies addressing the issue of energy use in housing. The knowledge of how to carefully renovate existing buildings has increased, but the incentives for cutting energy use further has diminished among property managers. As a consequence, there is very little renovation aiming at energy efficiency, which challenges the national goals of lessening the impact on climate change. One problem may be an incoherent and inefficient implementation of policies dealing with the preservation and the energy use of the built environment. Conclusions: The antagonism between energy efficiency and cultural heritage that emerged in the 1970s has changed in character. Above all, increased energy efficiency seems not to be a very strong force when designing renovation projects in homes. If Agenda 2030 goals of accomplishing a well-built environment that does not require unsustainable practices to be sustained are to be reached, new policies will be required. Grant support: The research has been supported by the Swedish Energy Agency (grant #50041-1).
Energy use patterns and renovations of Swedish second homes Mjörnell, K; Johansson, D; Femenias, P ...
13th Nordic Symposium on Building Physics, NSB 2023, Aalborg, Denmark,
2023, Letnik:
2654, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Abstract
During and post pandemic more people spent time in their second homes, which is expected to have led to higher energy use for heating. The knowledge of energy performance, heating systems, ...energy renovation and use patterns of second homes is still poor. The aim of the research is therefore to compile available information from building registers but also to empirically investigate user patterns, heating source and the renovation and energy efficiency measures carried out in second homes. A first step is to synthesize existing knowledge and develop a method for a broad mapping in a next step. The methods used are analysing statistics from national building registers and collecting information from owners/users through a pre-survey that is developed and tested. In this paper statistics on Swedish second homes and results from a pre-survey responded by 92 second homes owners/users are reported. From statistics, the energy performance and the main heating source for second homes with an EPC are identified. Despite the limited sample, the results from the pre-survey give an indication of user patterns, energy renovation measures carried out, and also whether the owners care about cultural values. Based on the experience from the pre-survey, a national survey has been initiated in Sweden.
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