uhl is the founder of imazon, a research institute located in the city of belém. pará state says that 50% of all private land must be maintained in forest. until recently, that was very hard to monitor. now, using a system of satellites okgps is casearcher clos sousaitiing realowhat it allows us to do is to pickp signals from the satellites. and through ocess of triangulation we can locate ouels rylyn gr and through ocess to within about ten meters. four... ey've got ur saites now. we are... probably... in this... area. mm-hmm. narrator: if the government chooses, it can use gps to locate property lines on satlite photographs of the landscape. they can then determine how much of a farmer's land has beenleared but enforcement is stty. anotg problem is 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 se