A basket weave is an observation in which one scan ha a “Scan PA” component set to “Along Width” and a second scan has the “Scan PA” set to “Along Height”. If you are mapping a small region you can simply do this within the same MSB. To do this copy the scan component and paste it below the original scan component and adjusting the “Scan PA” accordingly. You might also need to update the Sample Time to ensure your MSB remains a sensible length.
For larger scan areas (>0.5 degrees in size) you might have to have a separate MSB for the “Width” and “Height” due to the total length. If this is the case it is recommended you request in the notes that two observations are taken back to back to ensure an even coverage in terms of sky transmission (in terms of elevation and weather).