Although the effects of land management on roughness can vary due to soil characteristics, large roughness variations across a field are small. Consequently roughness will be measured at only two sites in each field. In addition, roughness will be measured only once since the SMAPVEX16-MB campaign will begin after seeding and further effects due to management activity are not expected.
Soil surface roughness will be measured over two sites of the selected fields using a digital camera and a 1 m-long profilometer installed in the look directions of Passive/Active L-band Sensor (PALS) and RADARSAT-2 sensor (descending mode). To adequately measure the correlation length, roughness measurements will be taken over 3-metre profiles. For each field, mean roughness values will be derived from the pictures of the 3-metre profiles taken at two sites with the digital camera.
|Needle profilometer||Needle profilometer|
|Number of sites per field||2 (same sites as RADARSAT-2)||2 (same sites as PALS)|
|Number of replicates per site||1||1|
|Number of profiles per site||3 (placed end-to-end)||3 (placed end-to-end)|
|Number of field visits||1||1|