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Military Navigation
| Applications | |
|---|---|
| Title | Military Navigation |
| Edited by | GMV |
| Level | Intermediate |
| Year of Publication | 2011 |
The satellite navigation is applied to military missions for navigation purposes in enemy territories, and are especially important in absence of light in night missions. The military forces rely on GNSS over conventional compasses, in order to obtain an accurate positioning of their own units, as well as the enemy's forces positions and the locations of enemy's facilities or installations. These positions coordinates can be acquired and distributed to other units, in order to enhance the ground awareness picture.
Satellite navigation is also used to plan and track the movements of convoys and in operations of search and rescue of injured soldiers, with considerable reduction of response time. Satellite navigation is used by military forces for ground navigation, aviation navigation and maritime navigation. Since military aviation navigation and maritime navigation are similar to their civilian counterparts this article will focus mostly on military ground navigation.
Application Architecture
The GPS was initially developed for military purposes and has proven to be indispensable for several military activities, such as land, air and sea navigation and accurate positioning for a wide range of military applications.[1] The use of GNSS has reduced the search and rescue operations response times, increasing the survival chances of the wounded soldiers.
The military navigation applications in current use, facilitate the following activities:
- Forces location,
- Forces navigation,
- Forces deployment,
- All weather and around the clock operations,
- Communication network timing.
The military applications are considered safety critical applications and in the case of GPS the military use the Precise Positioning Service (GPS PPS), which is a robust and encrypted signal with anti-jamming features.
GPS PPS uses both L1(C/A) and L2(P-code) frequencies while the Standard Positioning Service (SPS) uses only L1. The use L1 and L2 simultaneously allows among other things the removal of ionospheric errors and a more robust positioning. Detailed descriptions of Precise Positioning Service and Standard Positioning Service are available in GPS Services.
Galileo and modernized GPS will support multiple frequency signals for civilian uses and the accuracy difference between military and civilian GPS services will be reduced. Despite this the non-public services of GNSS systems will still have additional security and anti-jamming characteristics.
GPS modernization
An important part of the current GPS modernization program, is the new signal that is designed to improve both the security and prevention jamming properties of military navigation using GPS, the M-code.
The M-code signal provide better jamming resistance than the P(Y)-code signal (that defines the Precise Positioning Service), primarily through enabling transmission at much higher power without interference with C/A-code or P(Y)-code receivers.
The M-code design provides a more robust signal acquisition than is achieved today, while offering better security in terms of exclusivity, authentication, and confidentiality, along with streamlined key distribution. The M-code is designed to be autonomous, and so users will be able to calculate their positions using only the M-code signal, unlike the existing military P(Y)-code, which also requires use of the C/A-code, providing at least comparable performance to the P(Y)-code signal, and more flexibility than the flexibility offered by P(Y)-code signal.
While providing these benefits, the M-code signal must coexist with current signals on L1 and L2, not interfering with current or future civilian or military user equipment.[2]
Application Characterization
Forces location information is fundamental in military procedures. GNSS systems can turn the determination of the location of allied and enemy units into a simple task, with the proper equipments. With GNSS ubiquitous presence in military actions, troops must be constantly moving to avoid interceptions.
The tracking of troops is another useful application, since potential targets, must be tracked and monitored before an attack. This tracking procedures use other techniques such as photo reconnaissance combined with GNSS information, to enhance the awareness and providing guidance information to bombing missions.
Aircraft navigation is a military application, that also used for civil purposes, as it is documented in Aviation Applications article. The Maritime Navigation is also used by military vessels. In Maritime Applications article there are examples of satellite navigation applied to maritime navigation civil domain.
Remotely Operated Vehicles
Nowadays, the Unmanned Aerial Vehicles (UAVs) have a prominent importance in military actions around the world, due to the capabilities of being remotely controlled in military bases, located on a different part of the globe. The UAVs have increased the tracking and insight capabilities of enemy territories, in intelligence, surveillance and reconnaissance activities.
The UAVs used in military application have a GNSS receiver installed, along with the cameras installed in vehicle, allowing pilots to operate the vehicle, away from the conflict region. The GPS tracking systems are very effective in guiding the high-altitude UAVs controller in areas where the installed cameras fail, due to clouds or lower vision.
The GNSS receivers can also be useful for Attitude Determination in UAVs.
Signal Jamming
Signal jamming is a major thread to military operations based in GPS. The emergence of GPS jamming devices capable of broadcasting a signal in the same frequency used by satellite navigation to obtain location information, can drive to a disruption of satellite transmissions.
There are some military applications like the GPS Jammer Location (JLOC) designed to monitor for GPS interference threats and provide alerts to military users in the field when a threat is detected.[3]
Application Examples
The military GPS/GNSS devices appear up in many military applications for Force Deployment, Logistical Support and Vehicle Navigation, such as:
- Handheld receivers for soldiers,
- GPS-aided navigational systems for aircraft,
- GPS-aided navigational systems for unmanned aircraft,
- Navigational devices for vehicles, or
- GNSS jammers or anti-jamming applications.
Notes
References
- ^ A Lightweight GNSS Support Protocol For Military and Civil Applications, M. Tyson and C. Kopp, November 2007
- ^ Overview of the GPS M-Code Signal, Brian C. Barker, John W. Betz, John E. Clark, Jeffrey T. Correia, James T. Gillis, Steven Lazar, Kaysi A. Rehborn and John R. Straton, January, 2000
- ^ Global Positioning System, A Report to Congress, DoD, October 2008