Unfortunately, getting serious about border security is going to be a very expensive proposition; ground and airborne sensors will accomplish very little without adequate numbers of boots on the ground to effect arrests. And those boots cost $150K/year per pair.
Fine, do it. Cut back on all the nonsense programs to pay for it.
And also don't expect that to stop everyone - but also take the steps of mandating that only citzens or legal residents can receive government benefits, and step up enforcement of workplace violations of immmigration laws. If you do all three, you don't have to be perfect on any one to put a serious dent in the illegal migration.