CL_gm_pixelSize — Deformation ratio of a pixel for a given altitude and a given swath (tilt)
[K1,K2]=CL_gm_pixelSize(sat_alt,tilt,target_alt,[er])
Deformation ratio is defined as follows :
Note : this function assumes a spherical earth
satellite altitude [m] (1xN)
swath or tilt (depointing) angle [rad] (1xN)
(optional) target altitude [m] (default is 0 m)(1xN)
(optional) planet radius (default is earth equatorial radius %CL_eqRad) [m]
pixel ratio in tilt direction(1xN)
pixel ratio in perpendicular direction to tilt(1xN)
// Example 1 sat_alt = 700.e3; tilt = CL_deg2rad(20); [K1,K2]=CL_gm_pixelSize(sat_alt,tilt) // same computation, with CL_gm_visiParams : sat_radius = %CL_eqRad + sat_alt; target_radius = %CL_eqRad; [dist] = CL_gm_visiParams(sat_radius,target_radius,'sat',tilt,'dist') // distance for the given tilt [elev] = CL_gm_visiParams(sat_radius,target_radius,'sat',tilt,'elev') // elevation for the given tilt K1 = dist/(sat_alt * sin(elev)) K2 = dist/sat_alt // Example 2 tab_f=[]; K1=[]; K2=[]; fground=[]; leg=[]; i=0; f = scf(); drawlater(); xset("colormap",jetcolormap(10)); for sat_alt=[200000:200000:1400000]; i=i+1; fground=[fground ,i]; leg=[leg,sat_alt/1000]; f=[0:1:50]*%CL_deg2rad; [K1,K2]=CL_gm_pixelSize(sat_alt,f) ; tab_f=[tab_f;f]; plot(f*%CL_rad2deg,abs(K1)) p=gce(); p.children.foreground=i; end a=gca(); a.title.text="DEFORMATION DES PIXELS (K1)"; a.title.foreground = 12; a.title.font_size = 4; a.x_label.text="alpha (deg)"; a.x_label.font_size = 4; a.x_label.foreground = 12; a.x_location = "bottom"; a.y_label.text=" K1"; a.y_label.font_size = 4; a.y_label.foreground = 12; a.y_location = "left"; a.foreground = 12; a.data_bounds = [0,1;50,6]; legends("sat_alt: "+string(leg)+" km",fground,2); xgrid(); drawnow();