Teemu Tares

A helicopter-borne eight-channel ranging scatterometer for remote sensing. I. System description

For pt.II see ibid., vol.31, no.1, p.170-9 (1993). HUTSCAT, a helicopter-borne dual-frequency FM-CW scatterometer, is described. The HUTSCAT measures the backscattering properties of a target with a range resolution of 65 cm. The real-time ranging capability is obtained by performing the fast Fourier transform (FFT) to the received time-domain signal. The measurement is made simultaneously at eight channels (VV, HH, HV, and VH modes of polarization at 5.4 GHz and 9.8 GHz). The scatterometer measures the radar return spectrum for eight channels in 16.6 ms, which corresponds to an along-track distance of 0.33 m for the helicopter speed of 20 m/s. The radar system has been designed for remote sensing of forests, sea ice, and snow. >

Helicopter-borne measurements of radar backscatter from forests.

Abstract Helicopter-borne scatterometer measurements of various forest and surface types were conducted in spring 1988 in Espoo, near Helsinki. The scatterometer operates at 5-4 and 98 GHz and employs four linear polarizations (VV, HH, VH and HV). At each of the eight channels the radar can measure the backscattering properties of a target with a range resolution of 1 metre. The experimental results indicate that the location of backscattering sources within the forest canopy varies substantially with tree species. By applying principal-component analysis to the radar return versus range spectrum, identification of tree species is shown to be possible.

Classification Of Forest Types By Microwave Scatterometer

Helicopter-borne scatterometer measurements of vario forest and surface types were conducted in the spring 1988 in. Espoo, near Helsinki. The HUTSCAT (!:Ielsinkl University of Iechnology �terometer) operates at 5.4 GHz and 9.8 GHz and employs four 1 inear polarization modes (VV, HH, VH, and HV). At each of the 8 channels, the radar can measure the backscattering properties of a target with a range reso 1 ut i on of one meter. The fo 1 1 owi ng aspects of forest remote sens i ng were investigated: (a) the location of backscattering sources for various tree species, (b) determination of tree height, and (c) identification of tree species. Identification of tree species was examined using both the properties of the radar return vs. range spectrum and the principal component analysis.

Advances in unsupervised ship detection with multiscale techniques

This paper constitutes an example of analysis proving that new satellite borne full polSAR data is favorable for automatic ship detection purposes. In particular, this paper is based on a multiscale method for automatic ship enhancement based on the wavelet transform on single channel data and it proposes its extension to full polSAR images. Then, the enhancement of contrast of the ships with respect to the background sea reached with the method proposed is compared to that obtained by the classical polarization entropy.

Backscatter Behaviour Of Low-salinity Sea Ice At C- And X-band

A helicopter-borne dual-frequency scatterometer was used to investigate the backscattering behavior of low-salinity sea ice at 5.4 GHz and 9.8 GHz. The measurements were conducted in the BEPERS-88 Sea Ice Campaign in the Gulf of Bothnia, March 6-12, 1988. The backscattering properties of several sea ice types were examined at the two frequencies, using HH, VV, HV, and VH polarization modes.

Microwave Radiometer And Radar Measurements In The SAAMEX Campaign

The Surface and Atmospheric Airborne Microwave Experiment (SAAMEX) was held in Finland on 14-21 March 1990. The institutes providing airborne microwave sensors for the campaign were the British Meteorological Office (BMO) and the Helsinki University of Technology (HUT). The three main targets were sea ice, snow, and forest canopies. Ground truth measurements were made by several Finnish research institutes.

Development Of Airborne Dual-frequency Scatterometer

A he1 icopter-borne dual -frequency FM-CW scatterometer for remote sensing is described. The scatterometer can measure the radar b ackscatter from a target w ith a range resolution of one meter. The measurement is made simultaneously at eight channels (VV, HH, HV, and VH modes of polarization at 5.4 GHz and 9.8 GHz). 1. SUMMARY

A New Radar System for Remote Sensing

A helicopter-borne dual-frequency FM-CW scatterometer for remote sensing is described. The scatterometer can measure the radar backscatter from a target with a range resolution of one meter. This is accomplished by preforming the Fast Fourier Transform to the received time-domain signal. The measurement is made simultaneously at eight channels (VV, HH, HV, and VH modes of polarization at 5.4 GHz and 9.8 GHz).

Comparison of ERS-2 SAR, HUTSCAT and CARABAS results for boreal forest

A combined airborne and spaceborne radar remote sensing campaign on boreal forest was conducted in Tuusula, near Helsinki, in June and September 1997 in the framework of the EU EUFORA project. Airborne radar data was collected by the HUTSCAT ranging scatterometer on 6 and 12 June, and by the CARABAS SAR on 30 September. Spaceborne radar data include ERS-2 SAR images acquired on 1, 12, and 17 June. Ground truth data includes detailed information on weather, canopy, and soil parameters. The feasibility of various radar frequencies and polarizations for retrieval of forest parameters was investigated.

Maestro-1 Studies Using Data From JPLPolarimeter Sar And Hutscat Scatterometer

Helsinki University of Technology participates in the data analysis of MAESTRO-1 Campaign together with the Technical Research Centre of Finland. The goals of the HUT participation are the following: - Comparison of SAR polarimeter data from MAESTRO-1 Campaign (Freiburg test site) with data from HUT scatterometer measurements in Finland - Modeling and use of backscattering coefficient and relative phase angle in remote sensing of forest canopies. HUT ranging scatterometer measurements have been conducted in a test site near Helsinki at 5.4 GHz and 9.8 GHz, using 4 linear polarizations (HH, W, VH and HV) at each frequency. The forest canopies measured are similar to 6 small test areas selected within the Freiburg test site. The tree ages in our test site vary from 20 to 90 years.