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


Frequency9410 ±30 MHz
Number of channels2
Peak power output8 kW (per channel)
Average power output12 W (per channel)
Duty cycle0.16% (max.)
Pulse repetition2.0 KHz (max.)

Antenna and Pedestal

Antenna typeFront-fed parabolic
Antenna feedOrthogonal dual polarization
Primary diameter6 ft (1.8 m)
Beam width1.4°
Gain41 dB
Scan velocity60°/s (max.)
Scan acceleration60°/s² (max.)
Azimuth motion rangeUnlimited
Elevation motion range0° - 180°

RF Receiver

TypeParallel, linear
Number of channels2
Dynamic range90 dB (1 MHz)
Noise figure≤5 dB

Digital Receiver

Sampling rate250 MSPS (max.)
Dynamic range105 dB (1 MHz)
Frequency trackingAutomatic
Gain controlAutomatic
Range gates16384 (max.)
Sampling resolution1.2 m - 192 m

Signal Processing and Data Products

WaveformSingle or multiple PRF
Spectral processingClutter suppression,
2nd trip suppression,
Doppler unfolding
Polarization processingAttenuation correction,
hydrometeor classification
Data productsZ,ZDR,V,W,ρHV,NCP,ϕDP,KDP