## 7 Conclusions  
This paper presents the quality assessment results of C3S PROBA-V SA v1.0 products (broadband albedos) through intercomparison with reference satellite products (C3S SPOT/VGT SA v1.0 and MCD43 C6) at the global scale and the direct validation with a representative amount of ground data (1715 samples) across different biomes types (eight stations over forests, six over crops, three over grassland/shrubs, and three over desert). This validation exercise is a novelty in the literature, since very few global and temporally representative SA validation exercises have been published [21], and they are mainly based on MODIS observations [15; 16; 17]. The validation methodology adopted the guidelines, protocols and metrics defined by the CEOS LPV best practices for the validation of global albedo satellite products [21]. Additional results, such as the comparison of the spectral albedos or the presentation of the satellite products intercomparison per biome type, are not shown in this manuscript for the sake of brevity; however, they can be found in the product quality assessment report [66]. The main conclusions are the following. * The good spatio-temporal consistency of C3S PROBA-V and SPOT/VGT SA v1.0 products assures the continuity of the CDRs in terms of the uncertainty between products. However, C3S PROBA-V SA v1.0 (and MCD32A3 C6) provides low numbers of valid retrievals compared to C3S SPOT/VGT SA v1.0. * C3S PROBA-V SA v1.0 shows similar inter-annual precision (\(\sim\)1%) to MCD43A3 C6, improving the results of SPOT/VGT SA v1.0 (2-3%), since they provide some temporal instability over desert calibration targets. Both C3S products provide lower intra-annual precision than MCD43A3 C6, mainly in the NIR domain where some temporal noise was found. * The accuracy of the C3S PROBA-V SA v1.0 best quality retrievals with respect to the ground data over a five-year period (2014-2018) showed systematic positive overestimation, which was mainly observed for the lowest albedo ranges (SA \(<\) 0.2) over forest sites. Similar uncertainty (RMSD\(\sim\) 0.4) was found for MCD43A3 C6 products using the same sampling, showing the opposite sign for the mean bias. * Few current satellite EO albedo products comply with the GCOS, C3S and WMO uncertainty requirements. Additionally, it is important to remark that the use of PROBA-V QFLAGS (bit 6, input status; and bits 10-11, B2-B0 saturation status) removes most of the valid snow retrievals. Therefore, masking out data by means of the QFLAGS is not recommended for snow applications (users should ignore the information of QFLAGS over snow targets for specific applications). Based on these results, C3S PROBA-V SA v1.0 has reached validation stage 3 in the validation hierarchy of the CEOS LPV [20]. The continuity of the C3S SA CDR time series will be ensured using Sentinel-3 OLCI and SLSTR data, and the algorithm and design of the processing chain are currently being developed. C3S is also developing multi-sensor albedo products combining NOAA/AVHRR, SPOT/VGT and PROBA-V input data. The long-term CDRs, provided by the Copernicus Climate Change Service from 1981 to the present (with the aim of extending to the future), are an added extra compared with the existing EO programs, providing the longest and state-of-the-art albedo products. [PERSON] and [PERSON] conceived and conceptualized the work. [PERSON], [PERSON] and [PERSON] defined the methodology. [PERSON] and [PERSON] developed the validation software for generating the results. [PERSON] wrote the first version of the manuscript. All authors contributed to the analysis, writing, review and editing of the manuscript. The C3S_Lot5 consortium is structured as follows: validation team ([PERSON], [PERSON] and [PERSON]), algorithm development ([PERSON] and [PERSON]), project management ([PERSON]), and technical officer ([PERSON]). All authors have read and agreed to published the manuscript.