Hi all,

Is there a way to access plots that have already been filled in a Collect Earth project from different computers, in order to continue the process of classification?

Because from what I learnt so far, when we open a .cep file in a computer, a folder is created in C:\Users\”USERNAME”\AppData\Roaming\CollectEarth\projects.

So, I would like to know if when someone opens the same file, but from another computer, the information within the plots that have already been filled in is lost or if something can be done to overcome this problem.

This is important because the operators need to classify plots within the same .cep file both in Portugal and Guinea-Bissau.


Best regards.

asked 26 Apr '18, 11:29

cilopes's gravatar image

accept rate: 0%

This is a bit tricky in your situation.


Normally I would suggest you to use the option of connecting to a PostgreSQL database. You can find multiple posts in the support forum explaining how to switch from the default single-user local database (SQLite) to the multi-user server-based one (PostgreSQL).

Using the multi-user database ensures that all operators work with the same data and there is no risk of them assessing plots already done by others, as they can see the status (green tick) on the list of plots. The data that is exported from Collect Earth then also includes all of the plot data collected regardless if it was done by you or another user regardless of who collected it (as long as you are connected to the same db).

The problem with the PostgreSQL option is that it only works ifthe operators are in the same network. This is due to latency problems (the speed at which the computer connects to a server). If your PostgreSQL server is in Portugal, the ussers in Guinea-Bissau will have problems as the Collect Earth form is continuously sending requests to the Database server...thus the form in Google Earth will be really slow... I have previously testedthis using Amazon PostgreSQL serversand it was not really possible to use due to this speed issues.


So, simple solution that requires a bit of extra work: export the data for each operator, import it into a single computer and then export the data again and share it with all the operators, this way they will have the other operators data after importing it.

When I say import/export I am always referring to the XML/ZIP format.

Please if you are going to use this option let me know so I can explain the process in more detail.


If your aim is to make sure that users don't asses plot already assessed by other operators then the easiest thing to do is to divide the CSV file that contains the plot locations into as many files as there are operators. Give those CSV files the name of the operator is supposed to asses it eg. Johan.csv and then you tell Johan to select Johan.csv in the options dialog and then don't do any other plots.

This way the user will not even have the possibility to make mistakes.

When everyone is done collecting the data then they send the XML/ZIP file to the "main user" and this user imports all of the files to aggregate all the data.


We are working on anew product called Collect Earth Online. Right now itdoesnothave all of the features supported by Collect Earth but you might have a gooduse case for it.

Check http://collect.earth

This will allow you to proceed with the assessment in a more distributedfashion as it is completely web based so all the users have accesto the plots andthey are assigned randomly. As I said this is work in progress so it may require a bit of work on the survey.

So please, let us know more about your project so we can advise you better!!


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answered 29 Apr '18, 09:34

collectearth's gravatar image

collectearth ♦
accept rate: 17%


Thank you very much for your reply.

I think that the "Simple but laborious solution" is the best option for us. So, I would greatly appreciate if you could give more details about that process.

Best regards!

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answered 30 Apr '18, 12:26

cilopes's gravatar image

accept rate: 0%

Good choice!! Here's some more info

Background info

By default Collect Earth (CE) uses a SQLite local (file based) database. This means that each computer has its own data not accessible by any other computers.

In order to share information amongst operators CE has features to import and export data in multiple formats. The most convenient format is the XML one (which actually creates a ZIP file with many XML files inside it)

Furthermore, one has to be aware that the Database table where the plot information is recorded uses the plot ID ( or whatever attribute you set as the the key attribute of the record) as the unique ID to identify the record in the table. This is important to understand how the plot data can be overwritten by importing the won't files ( and also that it is important to make sure that the plot IDs are really unique amongst the different CSV files that you use in the assessment)

How to

So now. Say you have 5 operators, you are one of them and you are going to be the "super-user".

At the end of each day all the operators send you the data they have collected. They need to use the Tools->Data Import/Export->Export all data as XML/ZIP. The files that are generated ( which by default are named with the operators name and the date/time when they were generated) are then sent to you by email, or even better using a Google drive/Dropbox folder.

You, as the super-user, then proceed with these steps:

  • Import the data. Use the feature Tools->Data Import/Export->import new data from XML/ZIP . You will get many messages (not the first time you do this but after that) asking you if you want to override the data already in the Database (for the plots with the same IDs). Say yes, in case the operators have reviewed any plots from previous days and to avoid issues later when they import it back.

  • Start Saiku and check that all the data is there ( Tools->Start Saiku analysis )

  • Generate a file with all the aggregated data, same way than the operators did before, Tools->Data Import/Export->import new data from XML/ZIP

  • Send this file to the operators ( email/Google drive/Dropbox ) so that they import it using Tools->Data Import/Export->import new data from XML/ZIP. Also they should say yes to the option asking them if they want to overwrite.

  • Now all the users will have the same data!!!

Attention: this process will work best if the users only work on their own CSV files (plot location file). if they start mixing the plots that they will assess then you will have problems when importing data as it will be difficult to know which plots to overwrite. A possible solution is to use the Tools->Data import/export->xml->export data from date . This gives the operators the chance to choose the date from which to export the data. Meaning that if they do this everyday (at the end be off the day when they stop collecting data) and they choose the date of that day, then CE will only export the data for the plots that had been collected that day. This will avoid most issues with overwriting information.

Hope this clarifies. Please let me know if you need more info.

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answered 30 Apr '18, 14:20

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collectearth ♦
accept rate: 17%

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question asked: 26 Apr '18, 11:29

question was seen: 2,025 times

last updated: 30 Apr '18, 14:20