Hello.
During a current research and development on the topic processing of remote
sensing data (on the scale of the city and for the purpose of urban planning
and projection), my team and I faced with a list of problems, some questions,
that are eager to find answers.
* Sentinel-2 Data is downloaded in jpeg 2000 format, which is compressed
format and at preservation in this format there is the loss of the images
quality. Initially, Sentinel-1, 2, 3 Data should be free and accessible. But in
fact, we could hardly download the products in the format jpeg2000. But it is
impossible to process this images – the quality is horrible (we need more than
10 m/pxl).
* Found significant difficulties with the selection of Sentinel images.
Sentinel is a research project, so the satellites fly and automatically capture
images the whole territory. Among the array of historical data are very few
appropriate images. For each pilot cities, we managed to pick up only per 1
image for 2016. The rest are either in the wrong season or have a high
cloudiness (95% of the image).
Found images do not cover the whole territory of one frame of the city, and the
selection of the missing gaps is not possible due to the above indicated
problems. It is understandable, how to conduct regular monitoring in these
conditions. This leads to the idea that it is necessary to order satellite
imagery. Do you know, whom to contact about Sentinels and whether it is
possible to get from them the special, under the order images?
* The best resolution of Sentinel-2 data in four channels is 10 meters. This
is the upper limit of the spatial resolution that can be used for monitoring of
urban areas. And even only for undeveloped urban areas and inter-settlement
territories. On the territory of a thick building the image turns into mess,
and to obtain useful results it should be used paid high resolution images.
Where (if it is possible) can we download these satellite’s (Sentinel) images,
I mean from open resources?
* There is a big problem with data processing in free open source software
(SNAP, GRASS GIS, etc.). There is no any documentation and understandable
skills of Sentinel using, that is why all actions, making in these software,
are delayed for a long time and often do not lead to the expected result.
Thank you in advance.
__
С уважением,
Иванова Ю.А.
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