Fall 2006 - Air & Space Power Chronicle - Air Force Link

PIREP 31Link 16 and Joint Airspace Management andDeconflictionOne of the main input systems for the airpictureportion of the COP is information fedthrough Link 16, an improved data link usedto exchange near-real-time information (communication,navigation, and identification)that supports information exchange betweentactical C4I systems. One of the functions ofLink 16 is to provide positive, friendly identification.Link 16 periodically transmits a cryptosecuredand precise participant location andidentification (PPLI) report, a considerableimprovement that can significantly reduce orprevent fratricide incidents. 9 Part of the PPLIincludes geodetic positioning which would beimportant to JASMAD applications. Link 16messages implement a three-dimensional geodeticcoordinate system using latitude, longitude,and altitude. This enables positions tobe reported anywhere in the world and is subjectonly to display and database limitations.The geodetic grid (GEOGRID) is always availableto participants. 10 Herein lies the potentialapplication for the JASMAD: this is very similarto the Mode 4 identification, friend or foe(IFF) function used for primary aircraft separationin a radar environment.How does one maintain positive control ofairborne objects once they pass the FEBA andenter the objective area? Positive control innoncombatant areas is maintained by airtraffic-controlagencies using radar identificationand/or Mode 4 IFF reporting. When oneoperates in a wartime environment, radar controlis rarely available, and aircraft normallyturn their Mode 4 equipment off for operationalsecurity. This is part of the reason whyACMs are developed and the daily ACO is produced.Aerial vehicles flying on the ATO maintainseparation by the procedural methodsestablished in the ACO (differing routes, altitudes,and times). In air-traffic-control jargon,this is referred to as “procedural separation.”Procedural separation is not as effective forutilizing the available airspace as positive control.Larger blocks of airspace must be reservedfor operations when flying objects cannotbe separated by positive control. If amethodology for providing positive control ina secure operating environment were developed,air operations could be planned withgreater accuracy, fratricide incidents could beless frequent, and more aircraft could fly inthe battlespace with greater safety. The combinationof the COP, JASMAD, JMPS, and Link16 offers the potential to provide this capabilityand much more.A weakness of the Link 16 concept to helpprovide positive control in the battlespace isthat not all aircraft and aerial vehicles flying inthe ATO have or will have Link 16 capabilitiesor a similar interface system. For example,AMC currently operates some aircraft that employaircraft communications and reportingsystems, and eventually all strategic mobilityaircraft will meet ICAO aviation requirementsthrough the CNS/ATM program. Neither ofthese systems is interoperable with Link 16,and neither is secure. Thus, many AMC aircraftare not and will not be equipped to respondto positive air traffic control in thebattlespace. AMC is currently staffing initiativesto remedy the situation. Additionally,the number of unmanned aerial systems operatingbelow the coordination altitude isgrowing at an astonishing rate. Currentlynone have any system similar to Link 16, andalthough this is being considered for a few,most will never have Link 16 or any similarreporting capability. Another problem withthis concept is that Link 16 operates on lineof sight and requires a persistent airborneplatform to provide the link. Given all ofthese drawbacks, a solution may becomeavailable in the form of near-space platforms,which offer the potential to solve both theline-of-sight and persistence problems.Near Space and Joint Airspace Management andDeconflictionThe Air Force Space Battlelab is planning toconduct a variety of experiments in the areaof near space over the next several years. Thegoal is to determine if near-space systems flyingat an altitude of about 30 kilometersabove Earth’s surface could perform a varietyof tactical missions, including battlefield-