The formal technical and environmental specifications for the Garmin GRA 5500 digital radar altimeter (Unit Part Number: 011-02537-00) are outlined below: 

Performance Specifications

* Operational Altitude Range: Precise calculations from -20 feet up to 2,550 feet AGL (Above Ground Level). 

* Maximum Flight Envelope: Functions structurally at altitudes up to 55,000 feet maximum. 

* Altitude Accuracy Baseline:

* 3 to 100 feet AGL: Accurate to within ±1.5 feet.

   * 100 to 2,500 feet AGL: Accurate to within ±2% of actual terrain height. 

* Altitude Data Update Rate: Output time constant responds within a 0.1 second maximum. 

* Radar Transmitter Output: Operates on a "Gated" FMCW (Frequency Modulated Continuous Wave) architecture at 4.25 to 4.35 GHz with a 1.0 Watt nominal output power. 

Operational Envelopes

* Horizontal Airspeed: Operates accurately from 0 up to 200 knots maximum.  

* Vertical Speed Tracking: Trackable up to 20 ft/sec (below 100 ft AGL) and up to 25 ft/sec (above 100 ft AGL). 

* Attitude Angular Limits:

* Pitch Angle: Tracks fully up to ±20° maximum.

 * Roll Angle: Maintains primary accuracy up to ±20°; continues tracking with a secondary accuracy budget of ±20% down to ±30°.  

Electrical & Physical Attributes

* Input Supply Voltage: Automatically matches standard aircraft power buses at 14 VDC or 28 VDC nominal configurations. 

* Power Consumption: Draws an efficient 13.75 Watts maximum (equivalent to 0.5A at 27.5 VDC or 1.0A at 13.75 VDC). 

* Form Factor / Chassis Dimensions:

* Height: 3.99 inches (101.3 mm) with mounting rack.

   * Width: 3.02 inches (76.7 mm).

   * Depth: 11.62 inches (295.2 mm) with rack and rear connector profile; expands to 12.08 inches (306.9 mm) when a configuration module block is attached. 

* Chassis Weight: 3.5 lbs (1.6 kg) complete with standard mounting rack bracket hardware. 

* 

Regulatory & Software Compliance

* Software Design Standard: Certified to RTCA/DO-178B Level B stringencies. 

* Operational Temperature Boundaries: Rated to function reliably in un-pressurized or un-heated aircraft compartments from -55°C up to +85°C (-67°F to +185°F).