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Recently, I was able to successfully integrate Planet Labs satellite data into Collect Earth, thanks to a highly instructive Open Foris thread. I created my Planet API key, which allows me to access their imagery for 2 weeks free-of-charge. I am using it to assess forest and cropland dynamics in Southeast Asia. I have several issues and suggestions. Firstly, the Planet imagery in Collect Earth seems to be at a moderate to low spatial resolution. Despite the availability of sub-weekly imagery when and where it is available (which is extremely useful for tracking the exact dates of forest/cropland change), I found these images to be very blur, i.e. I am only able to confidently assess that the land cover type changed from forest to non-forest. I faced difficulty in trying to even identify the post-forest loss land cover type, e.g. is it cropland, or a home garden landscape? Has anyone else faced this issue? I was under the impression that we would be able to access the Very High Resolution (VHR) Planet lab imagery; Skysat, PlanetScope and RapidEye which have spatial resolution of 50 cm, 3.7 m and 5 m respectively. Instead, the public-use imagery in Google Earth (e.g. Maxar Technologies, Landsat/Copernicus) are at a much higher spatial resolution. I wonder if this is a result of using the 2-week Planet Labs free trial, and access to top-grade, hi-res imagery is only given to those who pay for the data. Secondly, I think the integration of Planet Labs imagery into Collect Earth is an extremely wonderful feature, that has been done very well by the Open Foris team. I would like to make a feature request; would it be possible to allow for the time-slider to only slide on dates where Planet imagery is available? I am suggesting this because as I scroll through the whole stretch of Planet imagery (2009 - present), I often stop at a date range where I am informed by a pop-up box that there is no imagery available. So, I move the slider (maximum date range on the slider bar) to-and-fro, until I can finally find a date-range where there is available imagery. Eventually, I spend a lot of time going through 'blank' dates where there is no imagery (which as I highlighted earlier, is of poor spatial resolution). |
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Great to hear that you managed to integrate the Planet imagery and that it is working to do it when getting the 2-weeks free tier. The question about the quality is noted, and there is not much we can do about it. The current integration with Planet is allowing only the access to the 3 and 4 bands Planet Scope images (3m pixels) through a web service offered by Planet for which we can pass filters ( the start and end date, the area of interest and the quality flag for imagery after 2014) and that returns a mosaic. You can see the code here : GitHub code I think that using the free 2-weeks access you can only use this imagery, correct me if I am wrong. You can check in the Planet Explorer The time slider request is dully noted and we have been already looking into it, we are having problems with the performance (searching all available imagery for an AOI is a bit slow) but as soon as we fix that it will be included in the interface. I feel that the Planet imagery would be much more useful if we could use false-color mosaics (using the infrared band for visualization) but apparently this is not possible yet through their web-service, so you need to download the image manually and change the color composite which totally makes this approach very time consuming. We will push for such a service so that we can use it in Collect Earth too! |
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I have just realized that I have not replied to your amazing response. Sorry for that. I really thought that I had replied a long time ago, but maybe my reply was not submitted for some reason. Regarding the quality of the free Planet Scope imagery during the trial period, I fully understand, thank you for clarifying this and sharing the link to the GitHub repo. I am not too sure about the post-2014 quality flag as I did not notice it when viewing Planet imagery in Collect Earth/Google Earth, but I can confirm that in the viewer, I am able to view coarse, medium resolution imagery when and where it is available, from 2009 till present. Thank you very much for considering the time slider request. Its integration would definitely make visual assessment processes more efficient, like when using the Google Earth time slider where you toggle between dates when imagery is available, but I am sure that the frequency of Planet images is substantially higher than those in Google Earth, which is why I can understand that it is a very challenging task. Thank you again. Finally, your point on viewing raw Planet imagery using false-color composites would make for an excellent addition to the Collect Earth infrastructure. On this point, I want to just share that Google Earth Engine is hosting a small amount of Planet imagery; multispectral and RGB SkySat for 2015 (view here), and very recently Planet Disaster Data which I also saw being incorporated in GEE (see this weblink), but imagine the possibilities if Collect Earth users could define custom RGB combinations for the false-colour composites on very-high-res Planet imagery, that would be very exciting indeed! All in all, I can understand and fully respect that the changes discussed in this thread are very time consuming, and that is okay, I am just very glad to know that Collect Earth is considering these improvements too! |
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There will be a release next week that will include the NICFI purchased Planet monthly basemaps (see article ) . This way the users in the areas covered by the NICFI agreement will have free access to the Planet archive ( we will keep the "old" way for users in non-tropical latitudes not covered by this agreement ) Look out for Collect Earth advising the user to perform the update! |