GANDER – for Global Altimeter Network Designed to Evaluate Risk – was an idea that was probably ahead of its time. Conceived at a time when ocean observing satellites were sometimes 10 years in the planning stage, the concept of affordable faster sampling through the use of altimeter-carrying microsats was primarily advanced as a way of detecting and tracking storms at sea on a daily basis. But...

The need for accurate geometric and radiometric information over large areas has become increasingly important. Laser altimetry is one of the key technologies for obtaining this geometric information. However, there are important application areas where the observing platform has its orbit constrained by the other instruments it is carrying, and so the spatial resolution that can be recorded by...

Single-photon-counting laser altimetry is a new measurement technique offering significant advantages in vertical resolution, reducing instrument size, mass, and power, and reducing laser complexity as compared to analog or threshold detection laser altimetry techniques. However, these improvements come at the cost of a dramatically increased requirement for onboard real-time data processing. R...

Global mean sea level rise estimated from satellite altimetry provides a strong constraint on climate variability and change and is expected to accelerate as the rates of both ocean warming and cryospheric mass loss increase over time. In stark contrast to this expectation however, current altimeter products show the rate of sea level rise to have decreased from the first to second decades of t...

As the goals for altimetric measurements become ever more precise, there is concern about the reliable detection and discarding of rain contaminated data. A dual-frequency rain detection technique developed for the Kuand C-band TOPEX altimeter, is adapted for the Kuand S-band RA-2 altimeter on Envisat. Of particular concern is the selection of a suitable threshold to minimise the quantity of go...

The long-term sea level change during 1993 to 2008 was investigated in the Malaysian seas from satellite altimetry data of the TOPEX, JASON-1, ERS-1, ERS-2 and ENVISAT missions. Sea level data retrieval and reduction were carried out using the radar altimeter database system (RADS). In RADS data processing, the 2008 updated environmental and geophysical corrections were applied. Six 1° × 1° are...

This work describes an accurate pulse radar altimeter which is simple and light enough to be carried aloft by a regular sounding balloon. The altimeter uses a single superregenerative stage serving as both the receiver and the transmitter. This stage is used in a feedback system in such a way that the period between transmitted pulses is a measure of altitude. The relatively slow rate of change...

The Radar Altimeter Database System RADS was launched by DEOS in 2001 as a precursor to an operational observing system as envisaged by the upcoming International Altimetry Service IAS. It is a facility to easily manage and access calibrated and validated altimeter data with consistency as common denominator. Whenever new data, models or knowledge arrive, the system is updated. We have now over...

Satellite altimeter data from 1993 to 2005 has been used to analyze the seasonal variation and the interannual variability of upper layer thickness (ULT) in the South China Sea (SCS). Base on in-situ measurements, the ULT is defined as the thickness from the sea surface to the depth of 16°C isotherm which is used to validate the result derived from satellite altimeter data. In comparison with a...

[I] The slopes of the wavenumber spectra of sea surface height (SSH) and kinetic energy (KE) have been used to infer "interior" or surface quasi-geostrophic (QG or SQG) dynamics of the ocean. However, inspection of spectral slopes for altimeter SSH in the mesoscale band of 70 to 250 km shows much flatter slopes than the QG or SQG predictions over most of the ocean. Comparison of altimeter waven...