Flightlines: PALS

The Passive/Active L-band Sensor (PALS) flightlines were designed to satisfy the major objectives of SMAPVEX 12. The PALS will be mounted at a 40 degree incidence angle looking to the rear of the aircraft; it will be augmented with additional components designed to detect and mitigate Radio Frequency Interference (RFI). During SMAPVEX12, the PALS will acquire passive and active L-band data at two elevations (Low and High) with along track spatial resolution of about 650 m and 1590 m, respectively.

Geometric features of PALS data acquisitions

Target altitude (m) Nominal ground elevation (m) MSL (m) Cross track resolution (m) Along track resolution (m) Footprint offset along track (m)
1067 305 1372 367 655 895
2591 305 2896 914 1592 2174

Low altitude lines will be used to provide high spatial resolution data for fields/sites with homogeneous vegetation conditions. Four lines were designed and the sampling sites will be located directly on these lines, to the degree possible. Low Line (LL) 1 and 2 cover a range of agricultural conditions, LL3 is focused on grassland and LL4 on forest.

High altitude lines (HL) will map a larger region that will provide data for simulating SMAP combined algorithms. A total of eight lines will cover a domain ~12.8 by 70 km. Lines are spaced ~ 1.6 km apart.

Location of low altitude PALS flight lines (in yellow) over the study region (black box).