Synthetic Aperture Radar

Synthetic aperture radar (SAR) consists of the following two parts:

  • 1. Antenna array (LRU01)
  • 2. Electronic unit (LRU02)

Radar block diagram

The radar can realize the control of the radar through the link between the data transmission system and the ground equipment, or it can work automatically through the preset route and working mode.

When the system works, under the control of the integrated processing module, the antenna can receive the radiation and echo signals of microwave high-power pulses, and the beam scanning driving function can be completed under the control of the integrated processing module. The transmitting module completes the modulation and power amplification of the microwave signal, which is provided to the antenna through the transmission channels such as the annular device and the rotary joint. The antenna radiates to the designated area. The low-power RF module provides a specified transmit excitation signal to the transmitting module under the control of the integrated processing module, and performs low-noise and large-dynamic linear amplification, frequency conversion, and filtering on the echo signal sent from the antenna. The intermediate processing echo data is provided to the integrated processing module, and the integrated processing module performs functions such as A/D conversion and full-time timing, signal processing and data processing, system control management, and data communication. The control information and the carrier data from the task management system are received, and the radar status is output to the task management system, and the scout image data is output to the on-board data transmission device. The power module transforms and filters the input power provided by the aircraft to provide various power supplies required by each extension of the radar.

Each LRU is connected together via internal buses and interfaces to form a complete unit to perform specified ground detection.

Main Function

  • Ground target strip SAR detection
  • Ground target high resolution spotlight SAR detection
  • Heavy rail interference SAR imaging
  • Real-time recording of radar raw data on device
  • Self-test

Performance

Item parameter
Center frequency Ku
Polarization mode HH/HV/VH/VV
Resolution 0.3m
Operating range 6Km
Mapping swath width 500m~3000m
Weight 3.1Kg(including POS)
Size 150*150*85mm
Power dissipation 65W
Data acquisition mode Pulse SAR
Data format Original echo data format and interface
SLC data format and interface
Operating mode Polarization/interference /GMTI

Processing Software

Function

  • Based on general GIS platform;
  • Man-machine interaction, graphic visualization and editing functions;
  • Secondary development function;
  • Airborne SAR interferometric self-registration imaging function (supporting motion compensation imaging processing);
  • Airborne SAR interferometric processing functions (geocoding, geometric correction, de-leveling, de-topography, filtering, de-tangling, DEM extraction, etc.);
  • Airborne heavy rail differential interferometric SAR processing (deformation extraction);
  • Key source code and subsequent function customization.

Application

SAR system can be widely used in basic surveying and mapping, disaster monitoring, resource and environmental investigation, emergency response, weather and hydrological detection, public security, target reconnaissance and other fields to meet the urgent needs of China's national security, economic construction and social development for high-resolution earth observation data. The development of this system will further improve our airborne SAR technology and has great application value in many fields related to our national economy.

Topographic mapping

The topographic mapping test and demonstration implementation methods include: the selection of test area, the work flow of the whole airborne SAR system and the test flight sequence, the flight planning, the ground work including angular reflector layout, differential GPS reference point setting and topographic control measurement, the data acquisition, the quality inspection, the product production, etc.

Disaster mitigation and relief

The techniques of remote sensing monitoring and evaluation on landslide disasters are researched and developed based on the airborne SAR data and database information. Then the disaster distribution diagram, the technical process standard of damage assessment and the prediction map are eventually generated by using the developed monitoring and assessment techniques and database information to carry out the airborne SAR’s monitoring on landslide disaster and the damage assessment demonstration in affected areas. In the specific implementation plan, the indoor disaster remote sensing monitoring, assessment technology and disaster assessment system design and the field flight measurement, monitoring and grounding verification are adopted together in the predetermined content research.

Basic science research

It is an important way for earth system science and remote sensing application research to obtain basic data by using the airborne SAR To obtain various physical information of target scattering in the observed area, such as the basic electrical parameters of target composition, directivity of target, density and thickness of scattering, superficial roughness, relevant length and scattering type; or target water content, target area biomas, etc.

Target reconnaissance

Since SAR can monitor all-weather and all-day from a long distance, it can be widely used in security monitoring, anti-terrorism reconnaissance, law enforcement and forensics, target detection and positioning, locating target’s relevant region, target identification, etc.

Others