The biggest limitation, bar none, to the effective use of satellite data is twofold: an astronomical amount of data flows to us from the skies, and trained analysts available to sift through it are few. Moreover, the number of analysts with domain knowledge to perform biosurveillance constitutes a subset of these analysts. Currently, the probability that space-based surveillance would miss the early signs of an epidemic or bioterrorism incident are high if only because a small hillock of relevant images would be buried in mountain ranges of other pictures.
Aircraft and satellites are affected by weather. Heavy cloud cover hides scenes of interest from cameras; storm activity can prevent aircraft or drones from flying their assigned missions. This is a factor in manmade epidemics. If bioterrorists understand that satellites are being used for surveillance, they are likely to attempt to strike when weather conditions most favor them, or to try as much as possible to conceal their attacks for as long as possible.
In addition to the technical limitations related to human bodies discussed above, other issues that would confront public health authorities are ethical (especially those related to privacy), and financial (we must pay for analyst time and spacecraft observation time). Indeed, it is likely that certain advocacy groups may protest the use of high-resolution satellite imagery for observation of people.
Important limitations to the use of military assets include legal restrictions that regulate military deployments on domestic soil and bureaucratic difficulties within federal agencies. The domestic use of military assets is restricted by many Executive Orders, Presidential Directives, Supreme Court decisions, and laws, such as the Posse Comitatus Act (U.S. Coast Guard, 2005). These legal directives, laws, and precedents exist to protect citizens from intrusion by the military and to ensure that military units remain subordinate to civilian control.
Aerospace assets are not controlled by one agency, but rather by a number of agencies; the different lines of authority tend to hinder efficient collection and dissemination of information. For example, the National Image and Mapping Agency is responsible for image intelligence products, while the National Security Agency collects signal intelligence.
Hence, the prompt distribution of information related to epidemics or bioterrorism, collected by such assets, to domestic agencies, is likely to be significantly hampered without the following:
• Anticipatory guidelines and policies consistent with federal law and able to withstand judicial scrutiny.
• Strong leadership in the federal government committed to cooperation between agencies that collect intelligence.
• Commercial satellite data are readily obtained; limitations are related primarily to the cost of their analysis and interpretation, and secondarily to the cost of data acquisition.
Putting spacecraft and aircraft to good use in biosurveillance will require significant investments in training experts who can interpret and analyze data, as well as research that could one day automate some of this process.
Was this article helpful?