PALSAR wide-area mapping and annual monitoring methodology for Borneo

This paper describes the operational radar mapping processing chain developed and steps taken to produce a provisional wide-area PALSAR forest and land cover map of Borneo for the year 2007, compliant with emerging international standards (CEOS guidelines, FAO LCCS). The methodology is based on the classification of FBS and FBD image pairs. To cover Borneo the equivalent of 554 standard images is required. The final overall accuracy assessment result shows this demonstration map product is in 85.5% full agreement with the independent reference dataset and in 7.8% ‘partial agreement’. Monitoring land cover change on an annual basis requires consistent year-to-year mapping. This implies that the localised and temporal effects of environmental factors on the backscatter level (such as inundation or El Niño drought) and variation due to differing observation dates/cycles (related to change of season) have to be accounted for strip by strip. New concepts for (a) automated intercalibration of radar data, (b) time-consistency and (c) automated adaptation of radar signatures to changing environmental conditions have been evaluated for its usefulness to improve the classification and the consistency of annual monitoring

Radar remote sensing data for applications in forestry

This thesis describes an investigation into the applications of radar remote sensing in forestry. During a four-year period (1982-1985), an extensive set of radar data was acquired at four test sites with forest plantations in The Netherlands: the Roggebotzand and Horsterwold sites at Flevoland and the Speulderbos and Kootwijk sites at The Veluwe. Two systems were deployed: a digital X-band SLAR and the multiband airborne scatterometer Dutscat. The thesis includes a description of these systems and the radar signal properties. Results of radar signature, transmissivity and canopy probing measurements are described. After discussing the physical properties of the radar data, the use of spatial analysis techniques is evaluated and the potential applications of radar data for classification and biophysical parameter estimation are elaborated. The thesis concludes with a conceptual elaboration of processing and data interpretation strategies

Radarreflecties aan bomen

Radar kan gebruikt worden om eigenschappen van natuurlijke materialen rechtstreeks te meten of te herleiden. De Vakgroep Bosbouw van de Landbouwhogeschool is in 1980 begonnen deze radarmetingen te ontwikkelen om eigenschappen van levende bomen en bossen vanuit de lucht te gaan bepalen. Een aantal grootheden van deze vrij nieuwe techniek worden beschreven en de eerste voorlopige resultaten worden geevalueer

Flood occurence mapping of the middle Mahakam lowland area using satelite radar

Floodplain lakes and peatlands in the middle Mahakam lowland area are considered as ecologically important wetland in East Kalimantan, Indonesia. However, due to a lack of data, the hydrological functioning of the region is still poorly understood. Among remote sensing techniques that can increase data availability, radar is well-suitable for the identification, mapping, and measurement of tropical wetlands, for its cloud unimpeded sensing and night and day operation. Here we aim to extract flood extent and flood occurrence information from a series of radar images of the middle Mahakam lowland area. We explore the use of Phased Array L-band Synthetic Aperture Radar (PALSAR) imagery for observing flood inundation dynamics by incorporating field water level measurements. Water level measurements were carried out along the river, in lakes and in peatlands, using pressure transducers. For validation of the open water flood occurrence map, bathymetry measurements were carried out in the main lakes. A series of PALSAR images covering the middle and lower Mahakam area in the years 2007 through 2010 were collected. A fully inundated region can be easily recognized on radar images from a dark signature. Open water flood occurrence was mapped using a threshold value taken from radar backscatter of the permanently inundated river and lakes areas. Radar backscatter intensity analysis of the vegetated floodplain area revealed consistently high backscatter values, indicating flood inundation under forest canopy. We used those values as the threshold for flood occurrence mapping in the vegetated area