MI-830 Family of RCS Pylons

MI-830 Pylon

The MI-830 Family of RCS Pylons provide safe and reliable target support for low-observable and RCS test and measurements. They cover a wide range of heights and boast load capacities up to 30,000 lbs (13,608 kg). MI-830 Pylons are designed as a polished structure with an ogive cross section in order to limit electromagnetic reflections.

downloadpdfStandard pylons have target load capacities of 1,500 lbs (680 kg), 3,000 lbs (1,361 kg) and 30,000 lbs (13,608 kg). Standard two-axis rotators of corresponding capacities are available for all MI-830 pylons. Pylon heights range from 5 ft (1.5 m) to 70 ft (21.3 m), and may be tailored to a customer's specific application. The structure is typically of polished aluminum monocoque design, with an ogive cross section of 4:1 ratio. Extremely large or special purpose pylons may have different shapes, ogive ratios or construction material. Extreme heights well over 70 ft (21.3 m) and load capacities up to 50,000 lbs (22,680 kg) are also available.

The mechanical interface between the rotator and pylon is carefully constructed as a continuous and smooth surface. Removal and installation of the rotator in most cases is facilitated by an access panel located at the base of the pylon. (The fasteners that attach the rotator are brought to the base of the pylon, where the access panel will not interrupt the polished surface where it matters most – within the electromagnetic test zone.) All electrical and fiber optic cable harnesses are contained within the pylon.

MI-830 RCS pylons incorporate several features to minimize their radar cross section. The pylon axis is typically tilted forward 30º from vertical. There is an included angle of 10º at the leading and trailing edges, which are sharpened to a radius of .003 in - .007 in (.08 mm - .18 mm) depending on the pylon size. Edge straightness is held to tight tolerances. RF energy reflected from the pylon is specular by virtue of the 63 microinch RMS surface finish of the outer skin.

The MI-830 family of RCS pylons is typically used in a compact range or far field system to measure the radar signature of a target. The role of the pylon is to place the MI-840 rotator and target at the desired height for testing, while contributing minimally to any energy that may be reflected back into the RF measurement system.

Specifications

Model MI-831-1.5K MI-830-3.0K MI-830-30K MI-830-50K
Load Capacity1 1500 lbs (680 kg) 3000 lbs (1,360 kg) 30,000 lbs (13,608 kg) 50,000 lbs (22,680 kg)
Height    5 - 70 ft (1.6 - 21.3 m)       5 - 70 ft (1.6 - 21.3 m)       20 - 70+ ft (1.6 - 21.3 m)       20 - 100 ft (6.1 - 30.5 m)   
Ogive Ratio2 4:1, 6:1 4:1, 6:1   6.5:1 6.5:1
Surface Finish

63 micro-inches RMS
(1.6 micrometers)

63 micro-inches RMS
(1.6 micrometers) 

125 micro-inches RMS3
(3.2 micrometers) 

125 micro-inches RMS3
(3.2 micrometers) 
Edge Sharpness 0.005 in radius 0.005 in radius  0.007 in radius  0.007 in radius
  Standard Material   Aluminum/Steel Aluminum/Steel Steel Steel

1 All capacities are target loads. Other capacities not shown are available..
2 Special non-ogive shapes available on request
3 63 microinches RMS available on request.

Design and Construction of MI-830 RCS Pylons

The pylon is an optimized structure which supports the target and presents almost no backscatter to the RCS measurement. The pylon is constructed of high strength steel or aluminum. Special positioner-to-pylon interface
allows the positioner and targets to be manipulated at ground level and then easily joined to the pylon with minimal or no dressing after installation.

The pylon is a metal "monocoque" or "single shell" welded structure. It allows for maximum structural rigidity with a minimum amount of weight. The shell of the pylon consists of the skins and the leading and trailing edges. The ribs, conduit, tip, and base plate finish out the welded structure. Various ogive ratio and shapes can be constructed as required.

MI maintains a comprehensive pylon development process; from the initial modeling phase, to the testing of the pylon, all the way to the shipping and delivery of the structure to the customer.

Testing of Pylon

The pylon is inspected thoroughly during the manufacturing process by visual, dye Penetration test and other methods as required. After the pylon is finished, proof load test and weld inspection are performed as part of standard product checkout procedure. Other non-destructive structural inspection such as magnetic particle inspection and ultrasonic testing can be performed as required.

Electromagnetic Analysis Using FEKO

MI utilizes FEKO, a comprehensive electromagnetic simulation software tool, to analyze the performance of different shapes of pylons to deliver the best possible results for our customers’ needs.

Shipping & Handling of Pylon

MI focuses on offering the best solutions for all of the packaging and shipping needs of our customers no matter the size or shape of the pylon. Pylon and rotator assembly are preassembled in factory.