Use of satellite images

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Replies: 6 - Last Post: December 04, 2012 20:31
by: mash909
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Posted: November 17, 2012 21:31 by mash909

hi The Java Magazine piece mentions that AgroSense uses satellite images.

*AgroSense uses satellite images, JPEGs, and open source and proprietary mapping services to create maps, and even allows farmers to draw their own*

I couldn't find any reference in the help documents. Can satellite images (or jpegs) be used to draw field boundaries?


Posted: November 19, 2012 10:25 by verhaget
AgroSense can import different types of sensordata. The sad thing is that we are not able to transform them to field boundaries yet. There is always the option to drag sensordata to the map, and manually draw a field based on the sensordata.

Posted: November 20, 2012 19:42 by mash909
apologies - I'm complete newbie - please can you advise what is meant by sensordata (I tried googling and the project help files).
how could I get sensordata which could produce field boundaries?
Posted: November 20, 2012 21:58 by Timon Veenstra
Currently the only way to import field boundaries is with ESRI shape files in WGS84 (gps) coordinate system.

Satellite data is always based on a raster.
The meaning of this data can vary based in the type of satellite measuring the data.
It can be normal color (regular images), or a specific spectral band like infrared or green.
The data from a satellite measuring specific band we call sensor data.
Infrared would produce temperature sensor data for example.

No matter what type of data the raster from a satellite contains, it is always a raster.
Creating field boundaries from a raster is quite complicated.
You can compare it to the select color option in photoshop.
It rarely exactly selects what you intended.

There are also data source which contain vector data.
Vectors are lines with a length and direction,
Geographical vector data would be a much better candidate for helping in determining field boundaries.
Even if we had the (lots of) money to buy commercially available geographical vector data, it would most likely not be detailed enough. They are usually created with planes with camera's attached to them. Those images are then processed into vectors. If those planes took their picture in the summer, imagine a road with large oaks on both sides. The canopies would make it close to impossible to determine where the field stops and the road begins.

Long story short:
option 1: use a gps device (trimble for example) to determine corners of the field and import the shape file it produces
option 2: draw the fields manually on the map

It would help if there was the option to put satellite images beneath the drawing map, instead of openstreetmap. We are investigating the possibilities for this. We did not find a reliable globally available data source though, so we might end up with a difficult solution to combine several local data sources.

Please subscribe to the announce mailing list to be kept informed about new features like this.

Hope this was an adequate explanation.

Posted: November 24, 2012 09:31 by mash909
Thanks for the detailed answer.
Do you have anything like user case studies online anywhere?
Posted: November 30, 2012 08:38 by Timon Veenstra
No not yet.

We are working together with Wageningen UR, who are currently doing research for best practices and business processes in agriculture. Parts of this research are already published. This research also shows the problems farmers have with current farm management tooling. We try to support the basic business processes described and solve those problems.

It is a good idea to publish some use case studies online.
Would you be interested in helping out in this part?

Posted: December 04, 2012 20:31 by mash909
Hi Timon
I'll reply offline
showing 1 - 7 of 7
Replies: 6 - Last Post: December 04, 2012 20:31
by: mash909