With the success of the Emergency Medical Hologram Project, Starfleet planners decided to spread out into three other arenas where this technology could be applied. This spawned the Emergency Engineering Hologram (EEH), and the Emergency Security Hologram (ESH), and the LCARS Interface Hologram (LIH).
Because of the posibilty of lower power allocation during a crisis, the EEH is transmitted from a portable tower which can be either self mobile, or carried by another crewmember.
The projector tower measures .75 meters tall by .4 meters wide and long. The top comprises of the internal forcefield generator, cooled by a cryogenic system and feeding the multiphasic array (MPA) matrix housing with high ouput microwaveguides. The MPA matrix is resposible for vectoring and manipulating the fields that make up a holograms body and solidity. Below the MPA is a band of omnidirectional holodiodes that generate the optical interference patters that make the EEH visible. The unit is powered by a sarium krellid battery.
The EEH is broadcast over subspace frequencies giving it an efective range of 53 meters away from the projector. At such distances the EEH will suffer optic degradation, being less visible, however the forcefields will not be affected. The EEH is also size variable and metamorophic, making it able to perform dangerous work in confined areas.
During testing in live exercises, EEHs have been able to stop core breaches within the time frame it would take a normal crew to seal off the section and eject the core.
The Emergency Security Hologram is the only hologram not meant to be presented anthromorphically, or with any personality subroutines. Basically it is a "smart" forcefield with red coloring for visibilty. The ESH is used to detain individual without blocking off the width of the corridor.
The LCARS Interface Hologram was orginally designed to represent the ships main computer, but was deemed to high a risk factor in that human decisions could possibly be counterminded by a vessel with a "mind" of its own. Instead the Library Computer Access Retrieval System was given the honor of being holographically represented. In keeping with the female voice, the LIH is female in appearance, and mannerisms, but has a limited personality as it is essentually an encyclopedia.