Jonathan Falke (à Tous): 14:56: How are Updates/Changes communicated/installed. Will This happen during current season. I expect some problems in comparablility between results from different Versions. Conventional agencies probably expect, that processing results are comparable results at least during current seasons. Can you comment on that?
Thomas Strasser (à Tous): 14:56: what ist the minimum size of parcels 
Thomas Strasser (à Tous): 14:57: ...required
Thomas Strasser (à Tous): 14:57: 10 day interval -> why not higher time density of time intervals?
Andrea Melchiorre (à Tous): 14:58: what is the relative importance of optical and SAR input data in the results accuracy?
Andrea Melchiorre (à Tous): 14:58: (can the system perform similarly with very sparse optical time series?)
Sophie (à Tous): 14:59: @Thomas: all parcels which have at least 3 S2 pixels inside and 1 S1 pixels inside are processed
Laurențiu Nicola (CS ROMANIA) (à Tous): 14:59: @Jonathan we generally try to support upgrades and we'll give a heads up if there are any expected compatibility issues in a new version. Right now we don't expect the results to change often, if at all.
Thomas Strasser (à Tous): 15:00: what is your experience of L2A product quality (respectivley MAJA) for hilly / mountaineous areas. is the quality of your results affected?
Sophie (à Tous): 15:01: @Thomas again: we tested a higher interval (up to 5 days) and we did not observe an increase of the accuracy, while significantly increasing the processing time. But I agree this choice is somehow subjective 
Sophie (à Tous): 15:02: @Andrea: it really depends on the characteristics of your area of interest. Cloud coverage first: if you have high cloud coverage, you will have many gaps in your S2 time series and S1 will be mainly used. The parcels size is also a constraint: S1 is at 20-m while S2 is at 10-m; so for small parcels, S2 is clearly more appropriate 
Emmanuel MONDON (à Tous): 15:03: Have you tested as well Sen4CAP with Very High Resolution (VHR) optical imagery ?
Ruben De March (à Tous): 15:03: For the training part, are the parcels labeled accordingly to the declarations or is there a ground truth for a sample of them?
Susanne Fröhlich (à Tous): 15:03: State Office for Rural Development, Agriculture and Land Reconcilation, Germany Department Brandenburg
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:03: @Ruben according to the declarations
Sophie (à Tous): 15:04: @Andrea again: clearly not; higher the density of the time series, better the results
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:04: @Emmanuel we currently don't support VHR imagery. What sensor are you thinking of?
Sophie (à Tous): 15:05: @Emmanuel: no, for the moment, Sen4CAP is running only with S1, S2 and L8 time series. Algorithms are designed to take advantage of the temporal dimension of the data of these data
Thanassis Dr (à Tous): 15:06: What percentage of the AOI must the sentinel image intersect in order to be downloaded?
Ruben De March (à Tous): 15:06: @Laurentiu why are used directly declarations? Couldn't they be subject to mistakes/faults?
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:06: @Ruben there could, but the classifier has some inherent resistance to noise, so with enough samples we expect the wrong declarations to matter less
Sophie (à Tous): 15:07: @Ruben: this is one of the reason we selected Random Forest - it is robust against "wrong" training data
Ruben De March (à Tous): 15:07: thank you both very much!
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:08: @Thanassis I think it's currently 5%
Shengyin Li (à Tous): 15:08: The zip file of visualization tool geopedia (mentioned in the tutorial) is not in the sen4cap Installation package. Where can we find it?
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:08: (5% of the S2 scene must overlap the AOI)
Sophie (à Tous): 15:09: @Shengyin: true; this is a separate package. We still need to put it on the website
Thomas Strasser (à Tous): 15:09: regarding minimum size of pixels: 3 S2 pixels -> how do you handle the spatial misregistration of S2 images? does this affect the results? to my knowledge a perfect matching of images is not provided yet.
Uwe Menzel, LGB (à Tous): 15:10: Crop-LUT: Is the "cropcode for detection" pre-defined with respect of the capabilities of the detection algorithm?
Gianrico (à Tous): 15:11: is possible to recive a certificate of attendance?
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:11: @Uwe no, the system just needs a list of the crop codes, their names and some attributes. The codes don't matter as long as they can be matched against the declarations.
Sophie (à Tous): 15:12: @Thomas: for the moment, we don't specifically address it. 
Gianrico (à Tous): 15:13: so, crop type is only a validation of in in situ data  not a prediction?
Nina Hofer (Statistics Austria) (à Tous): 15:13: is there a kind of "reference" value for how many parcels must have a crop class value for classification?
Sophie (à Tous): 15:13: @Gianrico: it was not planned, but if you really need it, it can be done
Jonathan Falke (à Tous): 15:14: Can we get a script of this chat as it is appering to hold a lot of usefule information for everyone.
Emmanuel MONDON (à Tous): 15:15: Maxar ones for instance as I am working for Maxar. So GeoEye, WorldView 1, 2 & 3 which are currently used by the on-going JRC control with remote sensing (CwRS)
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:16: @Nina I think the default is to classify crop types with at least 30 parcels
Thomas Strasser (à Tous): 15:16: a chat protocol you may find under C:\User\Documents
Sophie (à Tous): 15:16: @Gianrico: not at all. Roughly, 25% of the parcels declared by the farmers are used to build a random forest model. The remaining 75% of the parcels have been used to validate the products
Thomas Strasser (à Tous): 15:17: *.rtf (automatically stored, if not disabled in the settings)
Sophie (à Tous): 15:18: The split 25-75% is not the same for all crops (major vs minor crops). This is part of what I called the "optimized selection of parcels for training". You will find the full detail in the ATBD report available on the website 
Sophie (à Tous): 15:18: http://esa-sen4cap.org/content/technical-documents
Uwe Menzel, LGB (à Tous): 15:21: What means the LPIS-prosessor?
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:23: @Uwe it's an implementation detail that will be hidden in the next version
Sophie (à Tous): 15:23: @Uwe: the LPIS processor is calculating a set of quality indicators for each parcel. These indicators are used later on by each processor and they can also be used by the user (you) to interpret the results and get a better idea of their confidence
Andrea Melchiorre (à Tous): 15:23: Is there a publication or a public document available regarding sen4CAP results for grassland mowing? 
Sophie (à Tous): 15:24: These indicators are: (1) is the geometry valid (e.g. polygon is closed), (2) if polygons are overlapping each other, (3) if polygons are duplicated, (4) number of S1 pixels inside the parcel, (5) number of S2 pixels inside the parcel
henry hein (à Tous): 15:25: how can we know that product is geneated completely? even it shows "finished" in job history, sometimes, there's no result(empty) after downloading from product. thanks.
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:26: @henry that usually means there was a problem during execution. Ideally, it would never happen.
Sophie (à Tous): 15:26: @Andrea: there is a validation report for all products generated in 2018 and 2019 in our Sen4CAP pilot countries. This report is currently under review by ESA; as soon as it is approved, it will be put online
Uwe Menzel, LGB (à Tous): 15:30: oh, LPIS means here the claimed parcel not the reference parcel? 
Sophie (à Tous): 15:32: @Uwe: yes, correct. Our mistake 
henry hein (à Tous): 15:35: how long system will take to generate 1 tile from all SAT(S1,S2 & L8) if we run with 8 core, 64 GB Ram? let's see duration for crop is 4 months.  thanks. 
Fanie Ferreira (à Tous): 15:37: Sophie, you mentioned in the beginning of the Ppt "stratification" for different regions of "cropping practices": can you give more detail?
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:39: @henry I'm not sure, but probably around 3-4 days. But we generally process multiple tiles at once (e.g. 4).
Sophie (à Tous): 15:40: Hi Fannie, there is the possibility to upload a stratification of you area of interest into smaller more homogeneous areas. Then, separate classifications will be run for each sub-region (=each stratum) separately.  
Sophie (à Tous): 15:40: It has the advantage to work within more homogeneous areas, but it will have less training data in each area 
Sophie (à Tous): 15:41: I must say that for the moment, this option is not available through the web interface
Fanie Ferreira (à Tous): 15:44: Yes thank you it makes sensse what you are explaining, when a stratum is very small . Which button / tab has this option? 
Uwe Menzel, LGB (à Tous): 15:45: The training data are a part from the uploaded claimed data?  What ist the usual proportion of training to calcuaion data?
Sophie (à Tous): 15:45: @Fannie: unfortunately, this option is not yet available throuh the interface... 
Fanie Ferreira (à Tous): 15:46: Thank you
Sophie (à Tous): 15:47: @Uwe: for the crop type mapping, roughly 25% of the parcels are used for the calibration (but it can be more for the minor crops)
Uwe Menzel, LGB (à Tous): 15:48: That means, we have to trust this 25%. They are practically not monitored?
Marcin Pospieszny [PSNC] (à Tous): 15:48: Technical question : which part of SenCAP shold be instlale on SLURM CLUSTER workernodes when I want  to shedule Sen4CAP jobs to bigger HPC cluster?
Emmanuel MONDON (à Tous): 15:49: Are you considering using VHR imagery for QA/QC ?
Marcin Pospieszny [PSNC] (à Tous): 15:49: not at this moment
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:50: @Marcin there's an executor component that submits jobs using sbatch. The processors need to be installed on the worker nodes.
Sophie (à Tous): 15:50: These 25% are used to build a model, in our case a set of decision trees to reach each crop type class. In the random forest classification, this model is built by repeating the process several times and each time, not all the data (the 25% of the parcels) are used. This is why random forest is rather robust agains false detections
Sophie (à Tous): 15:51: Then, the model is applied to ALL parcels, even the 25% which were used to build the model
Andrea Melchiorre (à Tous): 15:51: The Maja 3.2.2 is no longer available on the CNES website, is the 3.3.2 TM compatible?
Thanassis Dr (à Tous): 15:52: Are you using the same percent of training data for each crop class? 25% total but how is it divided by class?
Thomas Strasser (à Tous): 15:52: how many observations (pixels / parcels) for the training are needed for 1 crop type at least that classification works? are the observations of training data are normalized to a equal number of each crop type, or is the training information unequal (for the later -> an overestimation for crops occuring more often would be more likley)
Sophie (à Tous): 15:53: @Emmanuel: validation of grassland mowing detection and of EFA practices monitoring algorithms has been done extensively in 2018 and in 2019 by using Planet data
Uwe Menzel, LGB (à Tous): 15:53: @Sophie Thank you. I have to do a closer look at the conceptual papers.
Sophie (à Tous): 15:53: You are welcome
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:53: @Andrea we should probably switch to MAJA 3.3 in the new version. It's possible that they are not compatible.
Sophie (à Tous): 15:54: It will probably be the MAJA v4.0 (which should be fully open source)
Mat Max (à Tous): 15:54: Question: Will we have access to the recording of this presentation?
henry hein (à Tous): 15:54: Thank you for all ur answers. how ndvi input is related to COHE and AMP input in custom job for generating L4C  agricultural practices? could you share if there's explanation and an example to run it?  thanks. 
Sophie (à Tous): 15:55: @Mat: we record this training and we will record the training of next week also, to build a clean material that will then be put online
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:56: @Thomas I think there's a threshold of 30 parcels for a crop type to be classified. We try to have the same number of samples for the same crop type to avoid the imbalance you mention.
Susan Vrona Bejina (à Tous): 15:56: thank you so much, fantastic presentation!
Mat Max (à Tous): 15:58: Thanks @Sophie
Laurențiu Nicola (CS ROMANIA) (à Tous): 15:58: @Thanassis it's 25% per class
Ruben De March (à Tous): 15:58: how can I retrieve coherence data directly from DIAS systems, if possible? otherwise, is there any other way?
Laurențiu Nicola (CS ROMANIA) (à Tous): 16:00: @Ruben the DIASes generally have SLC products (and GRD, I guess), but in Sen4CAP we compute the coherence ourselves. If you have a Sen4CAP installation, you can access the coherence products.
Ruben De March (à Tous): 16:02: yes, thank you
Susan Vrona Bejina (à Tous): 16:02: In terms of crop types, are we restricted to only those in the 4 participating MS?
Sophie (à Tous): 16:04: @Susan: not at all, you define your own legend, based on your declarations
Susan Vrona Bejina (à Tous): 16:04: ok super thank you
Chiara Leuzzi (à Tous): 16:05: So the system does not access CARD data, available on DIASes, right?