uhl is the founder of imazon, a research institute located in the city of belém.n pará state says that 50% of all private land must be maintained in forest. until recently, that was very hd to monitor. now, using a system of satellites casearcher carlos sousaig caust that.ps, okgps is realowhat it allows us to do is to pick up signals from the satellites. and thugh ocess of triangulation we can locate oursels rylyn gr and thugh ocess to within about ten meters. four... ey've gour sateites now. we are... probably... in this... area. mm-hmm. narrator: if the government chooses, can use gps to locate property lines on satlite photographs of the landscape. they can then determine how much of a farmer's land anotg problemeared but eis thenefficient way the cleared land is being used. the most common farming and grazing method here requires the farmer to cut tousandofirm spe,t it dry.ll set by farmers during the dry season to release the nutrients from the vegetation. but the soil's producvity disappears,n sometimes in one or two years. it forces settlers to abandon the