In order to orient aerial vehicles such as unmanned aerial vehicles and guided munitions toward intended target points, it
often becomes vital to acquire the correct information about the states of the targets during the flight of the vehicles. One
of the most widely-used ways to achieve this task is the utilization of seekers. Physically, the measurement capability of
seekers is restricted due to some physical, optical, and electronic limitations such as limited field-of-view (FOV),
atmospheric transmittance, and noise effects. Regarding these characteristics, basically two types of seekers are
employed in the relevant applications: strapdown or body-fixed seekers and gimbaled seekers. The strapdown seekers are
directly mounted on the considered vehicle body. Therefore, their measurements become relative to the body fixed
reference frame of the missile. For relieving the FOV limitations of the strapdown seekers, the gimbaled seekers are
preferred in some of the implementations. In this scheme, the seeker is mounted on a platform supported by two
orthogonal gimbals and stabilized by means of rate gyro feedbacks. This way, the FOV range of the seeker is increased
considerably. Also, the line of sight (LOS) angle and the LOS angular rate can be measured directly independently of the
missile motion. This study deals with the comparison of these two kinds of seekers according to certain criteria involving
mounting properties, FOV, angle and rate measurements, guidance method utilization, measurement methods, major
sources of measurement errors, and cost. A general evaluation is submitted at the end of the work.
Seekers are one of the most important subsystems of guided aerial munitions such that they are used both to detect and
track prespecified targets within specific engagement scenarios. Among them, infrared (IR) types constitute a significant
portion of seekers. Actually, performance characteristics of seekers depend on some certain factors. Regarding the type
of their sources, these factors can be classified as internal and external factors. Sensitivity, resolution, optics,detectors,
dome geometry, and materials happen to the most significant internal factors acting on the IR seekers while atmospheric
transmittance, and visibility can be counted within the remarkable external factors. In this study, the basic effects of the
above mentioned internal and external factors on the performance characteristics of a generic IR seeker is examined and
corresponding interpretations are presented at the end of the work.
Optical design of an imager that works in two sub bands of the infrared spectrum which are called midwave and
longwave (3-5 and 8-12 μm) is described in this work. The relevant design issue is not affected by the rate of change of
temperature in terms of various season and atmosphere conditions in operation. In this study, the first attempt dealt with
is to describe the broadband concept and to highlight that term. Then, basic information is presented about infrared subbands.
After describing the details of optical design in an infrared band, the decisions on necessary design parameters are
made. In this scene, environmental conditions regarded during the design process are chosen as challenging weather
conditions in Turkey within the range from -35 to 50°C.
Passive athermalization of infrared (IR) imager objectives such as thermal goggles and binoculars which are exposed to
variable atmospheric conditions is a critical issue. In this study, an athermal 50 mm f2 midwave objective design is
compared with three similar commercially available objectives in terms of modulation transfer function (MTF) in
Nyquist frequency under varying temperature conditions. The test setup constructed to enable the experimental
comparison and the test process utilized are described. Finally, the results obtained are comparatively evaluated.
Considering the aerial surveillance and reconnaissance applications the use of infrared detectors gains importance. In this
scene, one of the primary issues that should be decided happens to be the operating range of the detectors. Namely, the
midwave and longwave ranges which are usually defined in the ranges of 3-5 and 8-12 μm, respectively, come into the
picture as viable alternatives. In this work, the basic properties of infrared detectors operating in midwave and longwave
regions are presented and then they are compared in terms of certain performance criteria. The study is concluded by a
In guided munition applications, it is a priori to detect the intended target correctly and then to track it until the
termination of the engagement. However, especially high angular rates of the munition carrying an infrared (IR) type
camera cause the target image on the detector of the camera to blur. This, in turn, results in losing the correct target
information and even in missing the target. Therefore, it is required that the blur problem be handled carefully in an IRtype
camera design process. In this study, the blur problem of an IR-type gimbaled camera operating on a guided
munition is dealt with and the net field of view of the camera is determined for its different configurations. In the
calculations, the roll rate of the munition is taken into consideration because of the fact that it is much greater than its
counterparts in the yaw and pitch directions. Afterwards, the roll rate limit causing no blur is obtained and the ways that
can be applied to avoid this severe condition are proposed.