Index: /issm/trunk/src/m/utils/Meca/carter.m
===================================================================
--- /issm/trunk/src/m/utils/Meca/carter.m	(revision 9676)
+++ /issm/trunk/src/m/utils/Meca/carter.m	(revision 9676)
@@ -0,0 +1,28 @@
+function attenuation=carter(temperature)
+%CARTER - attenuation as a function of temperature
+%
+%   TWO WAY - Attenuation (in dB/m) as a function of temperature (K)
+%   From Carter at al. 2007 (Radar-based subglacial lake classification in Antarctica)
+%   Figure 4
+%
+%   Usage:
+%      attenuation=carter(temperature)
+
+if(temperature<0)
+	error('input temperature should be in Kelvin (positive)');
+end
+T=temperature-273.15;
+
+Temp=[-50 -45 -40 -35 -30 -25 -20 -15 -10 -5 0]';
+A=[0.0015 0.002 0.003 0.0042 0.0055 0.0083 0.012 0.0175 0.026 0.038 0.055]';
+
+%Now, do a cubic fit between Temp and B: 
+[cfun,gof,output]=fit(Temp,A,'cubicspline');
+%breaks=cfun.p.breaks;
+%coeff=cfun.p.coefs;
+
+%Calculate attenuation
+attenuation=cfun(T);
+
+%Make it a 2 way attenuation
+attenuation=2*attenuation;