Airborne Maritime Patrols – Oct 2005


Introduction

An automated maritime patrol module has been added to JFORCES. In essence, this module posts one or more aircraft (either fixed wing or helicopter) at a location and pulls them off as sea assets are detected within range. Topics within this document are:


Algorithm Overview

New Database Prototyping Inputs

New Scenario Generation Inputs

Runtime Interface Changes

Data Analysis Changes

Possible Improvements


This is a module with many options and there are undoubtedly loose ends. For that reason this document includes a section entitled “Possible Improvements”. Other sections are:


Algorithm Overview

Maritime patrols are models as one or more aircraft, wither fixed wing or helicopter, patrolling an area until a sea asset is detected. After a sea asset is detected the aircraft will attack the asset and return to base. An additional patrol control routine attempts to restaff the patrol with other aircraft from a list of candidate resources provided by the analyst.


Initialization

In the interests of completeness it should be mentioned that maritime patrol specifications are read from the database in the init_maritime_patrol routine, currently found in sim/engment/maritime.c. There’s no complex processing worth discussing beyond stating that this routine starts up a cyclical call to gen_maritime_patrols, which is the main routine for controlling and commanding assets on maritime patrol, if and only if one or more maritime patrol specifications are found in the scenario definition.


Invocation

There are two methods to initiating a maritime patrol. These can either be initiated by time or a number of elements of interest in a specific region. The event-based invocation will be described as part of the alternate plan implementation, with a write-up following soon. The time-based implementation is controlled by the gen_maritime_patrol routine , currently found in sim/engment/maritime.c. This routine is called once every simulated half hour. At that time it evaluates all maritime patrols and determines whether or not they are active. They can be declared active if the current simulation time is between the limits set by the analyst in scenario generation, or if the patrol has been declared active by an external module. At this time the only module that can activate maritime patrols is the alternate plan module, alluded to above. Some special notes:


Staffing

Maritime Patrols are defined as having a location. Currently aircraft fly small circles in location until an enemy ship is detected. The gen_maritime_patrols routine loops through all aircraft the analyst specified as available for use in this mission. It determines the total number of aircraft in flight versus the total number available and then assigns additional aircraft as required. Note that the total number of aircraft in flight is the criteria; this could lead to unexpected results if the aircraft are launched on other missions.


Prosecution

Aircraft launched on a maritime patrol initially fly towards the patrol point. However, whenever a detected enemy ship is within it’s on-board anti-ship sensor range the asset will attack that ship by flying towards it and dropping all of its ordinance. It will then return to base to rearm and refuel. Special notes:

New Database Prototyping Inputs

No database prototyping changes were required for this module. But some items of note that were found during testing are:

make sure the bases can turn around the aircraft/helicopters

make sure the aircraft have both warheads and appropriate sensors for antiship work

Verify the sensors have reasonable max range. This is used by the assignment routine. Too small of range and the aircraft will not be employed. Too large might result in assignments beyond the aircraft’s engagement radius (i.e. it’ll run out of gas before engaging the enemy).

Verify the aircraft/helicopters cruise speed and altitude. These are the values used both for flying to the patrol station and flying to the enemy. Too low of speed will result in exorbitant times-to-attack. Too low of altitude will deny detections because the enemy will be beyond the sensor’s horizon.


New Scenario Generation Inputs

New inputs are required to specify maritime patrols. These are found under Scenario Definition->Employ Automatic Rules->Plan Maritime Air Patrols, as shown in the figure on the following page. Specific comments:



Runtime Interface Changes

The only runtime interface change is that “MARITIME PATROL” has been added to the aircraft scramble button. It works fine.


Data Analysis Changes

Not changes to date


Possible Improvements