RXM-25 System Overview
Ridgeline Instruments' RXM-25 is a dual-polarization Doppler weather radar designed for dense networked deployment. Capable of covering ranges up to 50 km with range sampling resolutions below 40 m, the RXM-25 operates at X-band simultaneously transmitting and receiving horizontal and vertical linear polarizations. Built with an agile elevation over azimuth positioner system, the RXM-25 can reposition its antenna at a speed of 60 m/s and perform arbitrary scans through weather at speeds up to 24 m/s.
The RXM-25 uses a low operating cost magnetron transmitter capable of delivering up to 12 W of average power per polarization channel at a maximum 0.16% duty cycle, operating at single or dual PRF. A dedicated signal path and digital frequency tracking loop continuously monitors the magnetron's transmitted pulse frequency, peak power, length and start-up phase adjusting the radar receiver and signal processor operational settings in real time. An analog parallel receiver with low noise figure (< 1dB) LNAs, low phase noise (spec here) GPS disciplined reference oscillator, and a high ENR (> 30 dB) noise source for internal calibration down-converts the radar echo signals to an IF in the 100 to 200 MHz range. The RXM-25 eDAQ1B digital receiver delivers a stream of digitized I and Q signal components, together with all relevant radar state metadata, over a 1 GB Ethernet link.
All signal processing and radar control software runs on a single server style computer. The signal processor extracts the relevant radar product fields using spectral processing, adjusting in real time to changes in the radar operational settings such as transmitted waveform or clutter filter engagement. Doppler velocity unfolding, second trip echo suppression, clutter filtering and attenuation correction are part of the RXM-25 real-time signal processor. The radar control software is accessible through a Graphical User Interface for manual operation of the radar or from the command line for single or multiple radar automated control. Similarly, the radar data files can be automatically transferred to a central processing facility.
The RXM-25 radar is designed for ease of access and maintenance. All radar electronics are housed in two field replaceable enclosures, which can be pressurized along with the positioning system. This allows the system to operate in harsh environments without the protection of an overall radome.
Options for the RXM-25 radar include radome types and antenna and positioner sizes.
Technical Specifications
Transmitter | |
| Type | Magnetron |
| Frequency | 9410 ±30 MHz |
| Number of channels | 2 |
| Peak power output | 8 kW (per channel) |
| Average power output | 12 W (per channel) |
| Duty cycle | 0.16% (max.) |
| Pulse repetition | 2.0 KHz (max.) |
Antenna and Pedestal | |
| Antenna type | Front-fed parabolic |
| Antenna feed | Orthogonal dual polarization |
| Primary diameter | 6 ft (1.8 m) |
| Beam width | 1.4° |
| Gain | 41 dB |
| Scan velocity | 60°/s (max.) |
| Scan acceleration | 60°/s² (max.) |
| Azimuth motion range | Unlimited |
| Elevation motion range | 0° - 180° |
RF Receiver | |
| Type | Parallel, linear |
| Number of channels | 2 |
| Dynamic range | 90 dB (1 MHz) |
| Noise figure | ≤5 dB |
Digital Receiver | |
| Sampling rate | 250 MSPS (max.) |
| Dynamic range | 105 dB (1 MHz) |
| Frequency tracking | Automatic |
| Gain control | Automatic |
| Range gates | 16384 (max.) |
| Sampling resolution | 1.2 m - 192 m |
Signal Processing and Data Products | |
| Waveform | Single or multiple PRF |
| Spectral processing | Clutter suppression, 2nd trip suppression, Doppler unfolding |
| Polarization processing | Attenuation correction, hydrometeor classification |
| Data products | Z,ZDR,V,W,ρHV,NCP,ϕDP,KDP |