The Astana agreement (the result of peace talks between Russia, Turkey, the Syrian government, and rebels) mandated the construction of Russian and Turkish military observation posts along frontlines, with Russian posts inside Syrian government territory and Turkish posts inside rebel territory. The physical effects of this agreement can be easily seen with fresh satellite imagery (courtesy of EO Browser’s Sentinel 3). Below are selected timelapse images showing the construction of the bases.
Other Turkish military bases in Syria have not seen many changes over the past two weeks, partly because some have already been completed (as in Aleppo province), or possibly because more resources are being focused to newer sites. Construction on these new sites will only continue until the Turkish government has cemented an observation network (and quite possibly a border guard network) for its stewardship over the rebel-held part of Idlib and Aleppo provinces.