System Maintenance:
There may be intermittent impact on performance while updates are in progress. We apologize for the inconvenience.
By Topic

Inexpensive FM-CW Radar for Boundary-Layer Precipitation Studies

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

1 Author(s)
Williams, C.R. ; Cooperative Inst. for Res. in Environ. Sci., Univ. of Colorado at Boulder, Boulder, CO, USA

A vertically pointing C-band (5.8-GHz) frequency-modulated (FM) continuous-wave Doppler radar was developed for less than U.S. $6000, which can estimate the Doppler velocity power spectra from 20 to 300 m above the ground with a 5-m resolution. Three key design elements kept the costs low. First, the data acquisition system (DAS) commanded a direct digital synthesizer to start the FM sweep and then collected all voltage samples. This architecture insured phase coherence between the transmit FM sweep and the sampled voltages, which is critical for the Doppler processing that detects target phase changes over several successive FM sweeps. Second, a 5-m range resolution was achieved by increasing the FM bandwidth to over 36 MHz and decreasing the DAS sample rate to 500 kHz, enabling the use of an inexpensive DAS. Third, the Doppler processing at each range was achieved using two fast Fourier transforms (FFTs), i.e., a range FFT converted FM sweep voltages into in-phase and quadrature voltages I and Q at each range, and a Doppler FFT converted I and Q voltages from consecutive sweeps into the Doppler velocity power spectra. Observations show precipitation variability at 1-s and 5-m resolutions in the lowest 300 m of the atmosphere.

Published in:

Geoscience and Remote Sensing Letters, IEEE  (Volume:8 ,  Issue: 6 )