Comparison of L1 and L5 Bands GNSS Signals Acquisition.

Nowadays, civil Global Navigation Satellite System (GNSS) signals are available in both L1 and L5 bands. A receiver does not need to acquire independently the signals in both bands coming from a same satellite, since their carrier Doppler and code delay are closely related. Therefore, the question of which one to acquire first rises naturally.

Standalone GPS L1 C/A Receiver for Lunar Missions.

Global Navigation Satellite Systems (GNSSs) were originally introduced to provide positioning and timing services for terrestrial Earth users. However, space users increasingly rely on GNSS for spacecraft navigation and other science applications at several different altitudes from the Earth surface, in Low Earth Orbit (LEO), Medium Earth Orbit (MEO), Geostationary Earth Orbit (GEO), and feasibility studies have proved that GNSS signals can even be tracked at Moon altitude. Despite this, space remains a challenging operational environment, particularly on the way from the Earth to the Moon, characterized by weaker signals with wider gain variability, larger dynamic ranges resulting in higher Doppler and Doppler rates and critically low satellite signal availability.

Normalized GNSS interference pattern technique for altimetry.

It is well known that reflected signals from Global Navigation Satellite Systems (GNSS) can be used for altimetry applications, such as monitoring of water levels and determining snow height. Due to the interference of these reflected signals and the motion of satellites in space, the signal-to-noise ratio (SNR) measured at the receiver slowly oscillates. The oscillation rate is proportional to the change in the propagation path difference between the direct and reflected signals, which depends on the satellite elevation angle.

[Measurement of tumour response to cancer treatment: morphologic imaging role].

New forms of cancer chemotherapy are tested in therapeutic trials (phase I, phase II or phase III) while chemotherapeutic agents whose efficacy has already been demonstrated are used, in routine clinical practice, in the context of protocols. The overall survival rate is the best objective parameter of efficacy of the treatments tested, but this parameter is obtained too late, as the effect on the tumour must be determined as soon as possible in order to institute another treatment if necessary. Tumour response, or objective response, is based on changes in the number and size of measurable primary or secondary tumour "targets".

Mixed nonseminomatous germ cell tumor presenting as a subcutaneous tissue mass.

Extragonadal germ cell tumors most commonly arise in the midline of the retroperitoneum or the mediastinum. Primary tumors involving the skin are very rare. Only one case of malignant primary germ cell tumor located in the skin has been reported.

Gastrointestinal stromal tumors treated with imatinib: monitoring response with contrast-enhanced sonography.

Objective: The purpose of this study was to evaluate contrast-enhanced Doppler sonography with perfusion software as a predictor of early tumor response to imatinib (Glivec) in c-kit-positive gastrointestinal stromal tumors (GISTs).

Subjects And Methods: Thirty patients (59 tumors) with metastases or a recurrence from a GIST were prospectively included in a single-center imaging trial. Contrast-enhanced Doppler sonography was performed with an Aplio scanner the day before (day-1) starting oral treatment (400 mg) and at days 1, 7, 14, 60, 90, and 6 months, 9 months, and 1 year.

To predict progression-free survival and overall survival in metastatic renal cancer treated with sorafenib: pilot study using dynamic contrast-enhanced Doppler ultrasound.

Introduction: The objective of this study was to evaluate dynamic contrast-enhanced Doppler ultrasound (DCE-US) with perfusion software (Vascular Recognition Imaging) and contrast agent injection as a predictor of tumour response, progression-free survival (PFS) and overall survival (OS).

Patients And Methods: Thirty patients with a metastatic renal cell carcinoma (RCC) already enrolled in a double-blind randomised study were evaluated. Examinations were performed at baseline, and after 3 and 6 weeks on sorafenib or a placebo in patients with tumour targets that were accessible to DCE-US.

Prognostic value of angiogenesis evaluated with high-frequency and colour Doppler sonography for preoperative assessment of primary cutaneous melanomas: correlation with recurrence after a 5 year follow-up period.

Objective: To study the value of high-frequency sonography (HFS) and colour Doppler sonography (CDS) in evaluating the 5 year metastatic potential of primary cutaneous melanomas (CM).

Materials And Methods: 111 CM were studied before surgical resection and 107 were depicted on HFS. The maximal HFS thickness was measured and compared with the Breslow thickness.

Doppler US with perfusion software and contrast medium injection in the early evaluation of radiofrequency in breast cancer recurrences: a prospective phase II study.

Introduction: The aim of this study was to determine the efficacy of Doppler ultrasonography (US) with perfusion software and contrast agent injection (DUPC) during radiofrequency (RF) treatment of local recurrent breast cancer.

Materials And Methods: Ten patients were included in this monocentric prospective phase II study. DUPC was performed for each patient the day before treatment and immediately after RF in the operating suite.

[Interest of color Doppler ultrasonography to evaluate a new anti-angiogenic treatment with thalidomide in metastatic renal cell carcinoma].

Purpose: To assess the effectiveness of Doppler Ultrasonography (DUS) in evaluating the anti-angiogenic effect of thalidomide.

Materials And Methods: [corrected] Forty patients with metastases of cancer of the kidney were included in a phase II therapeutic trial. Twenty eight had tumor targets which could be evaluated by DUS.

High-frequency sonography and color Doppler in the management of pigmented skin lesions.

We aimed to evaluate high-frequency sonography (HFS) coupled with color Doppler in the management of pigmented skin lesions (PSL). HFS examination was performed in 111 patients with 130 PSL. A color Doppler study was conducted in 107 lesions, to assess intralesional vascularization.

Hepatic focal nodular hyperplasia in children previously treated for a solid tumor. Incidence, risk factors, and outcome.

Background: The detection of hepatic nodules, particularly in patients treated for a previous malignancy, raises a diagnostic dilemma. Focal nodular hyperplasia (FNH) of the liver is an uncommon, benign tumor in children and must be differentiated from malignant hepatic lesions. The etiology of FNH is obscure, and its pathogenesis is poorly understood.

Prognostic value of doppler-ultrasonography in hepatic veno-occlusive disease.

Background: Currently, the severity of veno-occlusive disease (VOD) is graded retrospectively on the basis of the evolution of clinical and biological criteria. The objective of this study was to describe a noninvasive method capable of predicting the severity of this disease at the time of the diagnosis.

Methods: Seventy-one children who developed VOD after intensive myeloablative therapy with busulfan before hematopoietic stem cell transplantation were included in this study.

Prognostic value of angiogenesis evaluated with high-frequency and color Doppler sonography for preoperative assessment of melanomas.

Objective: The aim of our study was to confirm the value of high-frequency and color Doppler sonography in evaluating the metastatic potential of melanomas.

Subjects And Methods: Sixty-nine histologically proven melanomas in 67 patients were prospectively studied before surgical resection. A morphologic study was performed with a 20-MHz probe.