%%?RADARSAT_RDA_Imaging.m?
%?用RD算法對RADARSAT-1的回波數據成像?
%?author:?四院五隊?王建（07042185）?
%?為了節省程序的內存開銷，代碼中包含了較多的clear語句?
%?為了減少程序運行時的內存開銷峰值，長表達式分多步實現?
?
%%?抽取數據?
?
%?在文件specify_parameters.m中指定相關參數?
specify_parameters;?
%?從文件中抽取數據?
extract_data;?
%?對數據塊1進行成像?
AzimuthBlock=2;?
%?加載數據?
load（strcat（output_path‘CDdata‘num2str（AzimuthBlock）））;?
file_pre?=?strcat（?output_path?output_prefix?‘_‘?num2str（AzimuthBlock）?）;?
%?得到自動增益控制（AGC）值?
AGC_values?=?load_AGC_block（?file_pre?first_rg_line?...?
????Nrg_lines_blk?AzimuthBlock??UseMATfiles?）;?
%?AGC還原，得到真實的回波數據?
org_data?=?load_DATA_block（?file_pre?output_path?Nrg_lines_blk?...?
????Nrg_cells?AGC_values?AzimuthBlock?UseMATfiles?）;?
%?以下所有的clear語句都是為了節省內存開銷?
clear?AGC_values?
data=org_data;
%%?進一步明確RADARSAT-1的相關參數?
%--------------------------回波模型參數設置-------------------------------------------%
%%?進一步明確RADARSAT-1的相關參數?
thetaT=90*pi/180;
?
length_replica??=??2880;?????????%?Total?length?（I&Q）?of?replica?record?
tot_Nrg_cells???=??9288;?????????%?Total?number?of?range?cells?per?line?
tot_Nrg_lines???=?19432;?????????%?Total?number?of?range?lines?（records）?
first_replica???=?????7;?????????%?First?record?that?contains?the?replica?
PRF?????????????=?1256.98;???????%?Pulse?Reputation?Frequency?（Hz）?
Fa??????????????=?PRF;???????????%?方位向采樣頻率?
Fr??????????????=?32.317e+6;?????%?Radar?sampling?rate?（Hz）?
f0??????????????=?5.300e+9;??????%?Radar?center?frequency?（Hz）??
c???????????????=?2.9979e+8;?????%?Speed?of?light?（m/s）?
t0??????????????=?0.0065956;?????%?data?window?start?time?
R0??????????????=?0.0100386*c/2;?%?Slant?range?of?first?radar?sample?（m）?
%R0=R0/sin（thetaT）;
%R0??????????????=?0.0100800*c/2;?%?Slant?range?of?first?radar?sample?（m）?
%R0=1.5005e+006;
R0=R0/sin（thetaT）;
Nrepl???????????=?1349;??????????%?No.?of?valid?samples?in?the?replica?
Kr??????????????=?0.72135e+12;???%?FM?rate?of?radar?pulse?（Hz/s）?
Tr??????????????=?41.75e-6;??????%?Chirp?duration?（s）?
v??????????????=?7062;??????????%?Effective?radar?velocity?（m/s）?
lambda??????=?c/f0;??????????%?Radar?wavelength?（m）?
Ka??????????????=?1733;??????????%?Azimuth?FM?rate?（Hz/s）?
fdc????????????=?-6900;?????????%?Doppler?centroid?（Hz）?
%f_dc?????????????=-7063
Lr??????????????=?15;????????????%?Range?Aperture?
La??????????????=?1.5;???????????%?Azimuth?aperture?
Na_mf???????????=?705;???????????%?方位向上匹配濾波器長度?
Ta??????????????=?Na_mf/Fa;??????%?the?duration?of