The　accumulation　rate　is　a　key　parameter　in　computing　the　mass　balance　of　glaciers　and　ice　sheets　to　estimate　sea　level　rise.　A　shallow-layers-detection　ice　sounding　radar　(SLDISR)　is　developed　to　measure　the　accumulation　rate　and　shape　of　near-surface　internal　layers　with　high　resolution.　With　a　transmitting　frequency　from　500　to　2000　MHz,　this　frequency-modulated　continuous　wave　(FMCW)　radar　provides　a　range　resolution　of　about　16　cm　in　free　space　by　using　a　Hanning　window　and　a　penetrating　depth　about　150　m　under　polar　ice.　The　spectral　analysis　and　coherent　integration　techniques　are　used　to　obtain　a　high　processing　gain　and　to　improve　the　signal-to-noise　ratio　of　the　system.　A　phase-locked　loop　with　wideband　yttrium　iron　garnet　(YIG)　oscillator　is　applied　to　generate　a　sweeping　chirp　signal　as　an　input　source　for　the　transmitter.　A　stable,　low-frequency　reference　chirp　signal　is　generated　with　a　direct　digital　synthesizer　(DDS)　integrated　in　field-programmable　gate　array　(FPGA).　To　reduce　the　high-speed　requirement　to　the　analog-to-digital　converter　(ADC),　dechirp　technology　is　adopted　at　the　RF　section　of　the　receiver.　The　implementation　of　the　digital　unit　is　based　on　an　FPGA　chip.　The　designed　radar　has　been　successfully　deployed　in　Antarctica　during　the　31st　Chinese　Antarctic　Research　Expedition　(CHINARE　31)　and　CHINARE　33,　mainly　over　the　East　Antarctic　Ice　Sheet　(EAIS).　The　echograms　indicate　the　effectiveness　of　the　radar　system　on　detecting　clear　internal　reflecting　horizons　(IRHs)　over　ice　sheets.