Satellite Altimetry - Science topic

The general characteristics of Satellite Laser Ranging (SLR): The photons returning are usually fewer because the transmitting laser and retroreflectors both have a divergence. This means that the laser beam spreads out as it travels, which can affect the accuracy of the measurement. How can this divergence be minimized?

the above question is regarding the source to download Saral/Altika satellite altimetry GDR (Geophysical data record) data. Actually in "earthdata.nasa.gov" website Saral/Altika raw data OGDR (Operation GDR) is available. But I want to know only GDR data.

We have analyzed changes in sea level in time in the Odessa Bay of the Black Sea according to satellite altimetry data and in Odessa according to coastal observations. It turned out that there is no complete match. In addition, sometimes there is no coincidence even of trends. In the period 2004-2005, according to the level measurement at the coastal point, a downward trend in the level was recorded, and according to the satellite altimeter, a trend in the level increase was recorded. The charts are attached. We believe that during this period there was an uplift of the level gauge (uplift of the land and the seabed). What do you think?

I downloaded the data and I need to get the elevation values. The data contain different variables and now I am unable to select the right variable which will give me elevation.

I‘m trying to measure land altitude from Sentinel-3 altimeter (such as min/max altitude above ellipsoid over one footprint of a beam). But when I‘m listing through available operations in BRAT software, they are all dedicated for SEA, ICE, etc.

Can someone give me some hint/link for a manual for LAND use of Sentinel-3 altimeter?

Thank you!

Satellite altimetry is usually used for assessing relative changes in water levels, in lakes, seas etc ... why the same technology can not be used in terrestrial surfaces?

I'm interested in looking at small to mesoscale eddies in conjunction with discrete biological, chemical and physical data collected over the eastern Bering Sea shelf. I'm aware that tidal influences become problematic in coastal shallow areas but would like to know if there's a way around this.

For my study region, I would like to know the tidal height value for each day of sampling during study period for the water sampling locations? As some measurments dated back 3-5 years ago, i do not have tidal charts for the study location. So i would like to use utilise satellite remote sensing for this purpose? how to proceed? 

In common view mode, the ground to ground time transfer by Two- Way satellite Time and Frequency Transfer (TWSTFT), What are the different models which reduces the noise of the space clocks?

Hello Researchers, I have a question related to sea level rise in the coastal region of Gujarat. How can I assess the local sea-level rise for the coastal region of gujarat as there are many few stations which has tide gauge level data?

Also satellite altimetry provides regional MSL which needs to be downscaled to coastal level of western India especially Gujarat.

Regularly, geodesists at international colloquium wonder what is the next big step in geodesy (see Geodesy and its future, A. Dermanis & F. Sanso /the role of geodesy – C. Rizos – FIG 2012). If we exclude engineering applications associated with the rise of GNSS and all the new constellations (GLONASS, Beidou, Gallileo,…) which will indubitably promote new technological niches in the Location Based Services market beyond navigation and tracking applications.

We are then left with the applications of geodesy to geosciences a.k.a environmental geodesy- e.g. . the study of reference frame in geophysics with plate tectonics movement & earth rotation; oceanography with multiple applications including the measurements of tides, height datum and bathymetry; in climate change – geodesists estimate the sea-level rise around the world. Nowadays, geodesists need to analyse different satellite missions (GNSS, GRACE, satellite altimetry …) and correlate various observations in order to produce robust models and describe/discover new natural phenomena. Thus, does the future of environmental geodesy rely on AI and big data algorithms to process & analyse large amount of data and build empirical models used in the analysis/prediction of natural phenomena? With the need to monitor closely climate change, geodesists will be involved in studies involving the data analysis of future satellite missions (see my previous question on “big data and climate change”).

Last but not least, with the willingness of exploring Mars and other planets, a future field of interest may be the application of geodesy in the analysis of geophysical phenomena occurring on those planets…. What do you think?

Recently, many scientific applications such as:

In geology, the inversion of the geoid is used for Petroleum Exploration.

I am looking for studies and research in this field

I am new for Generic Mapping Tool (GMT), but I would like to work through a few simple examples of generating legends (ie. multiple points or lines plotted on a single figure using psxy). In the following example, I want a set the location of Legend in the southwest (Inside bottom-left of axes).

gmt psbasemap -R-108/-105/31/35 -JM6i -Ba0.5 -K -P> New_Mexico.ps

gmt pscoast -R -J -Df -Gwhite -O -K -P>> New_Mexico.ps

gmt psxy Data1.txt -R -J -Sc0.5c -Gblue -O -K -P >>New_Mexico.ps

gmt psxy Data2.txt -R -J -St0.5c -Gred -O -K -P>>New_Mexico.ps

gmt psxy Data3.txt -R -J -Ss0.5c -Ggreen -O -K -P>>New_Mexico.ps

I am looking for a research about:

Comparison between the three dedicated gravity fields mapping mission, [CHAMP (1996), GRACE (2002) and GOCE (2009)], in geoid modeling (when using the satellite-only model related to these three mission)

Conversion between different permanent tide systems involves either modifying one spherical harmonic coefficient or adding a zonally uniform correction to the geoid undulations.

 More information sees

I want to calculate moho depth and I have only satellite gravity data. Does satellite gravity data give good result?

I reccently use the newly issued surface geostrophic velocity data from AVISO, and I have a question about the accuracy of the altimetry data. Because the velocity is calculated from ADT, which is the sea surface height (SSH) above the geoid. Firstly, I found a validation report in AVISO website between tide gauge and SSH data, and the difference can be 0.04 m at my area, which could introduce large discrepency from the calculation of velocity (V=(g*diff(adt))/(f*diff(distance))).

I am wondering if this validation is suitable for the velocity, or there are other validations concerning to the geostrophic velocity calculated from altimetry data.

As possible, any researcher helps me to getting this research

G. WEBER, 1984: Hochauflösende mittlere Freiluftanomalien und gravimetrische Lotabweichungen für Europa. Wissenschaftliche Arbeiten der Fachrichtung Vermessungswesen der Universität Hannover, Nr. 135, Hannover, 1984

H.-G. WENZEL, 1985: Hochauflösende Kugelfunktionsmodelle für das Gravitationspotential der Erde. Wissenschaftliche Arbeiten der Fachrichtung Vermessungswesen der Universität Hannover, Nr. 137, Hannover, 1985

Please send me a link to download this references

The ground tracks of a single satellite cross each other after a certain time. At the intersection of two ground tracks (called crossover) the altimeter system allows to observe the sea surface twice. If the sea surface would not change, the sea surface heights derived from measurements of both ground tracks should be identical. In reality, the difference of sea surface heights (the so called crossover differences) do not vanish due to errors of the orbital height

I am interested in doing research on sea level rise. How can we get altimeter data for doing research on  sea level rise

GRACE and other satellite missions have many applications one of them is investigation of the change in water content 

how can I do that with GRACE or other missions data?

what the type of data used for this purpose?

Such as in:

Triple collocation

Jur Vogelzang and Ad Stoffelen

Document NWPSAF-KN-TR-021

I have some questions about Global Gravity Field Models (ICGFM).

Where How to Calculate Coefficients of this model? I.e. I need the program to compute spherical harmonic analysis of EGM model.

These days I am  studying about Radar Altimetry, to fully understand the Cryosat mission. By the way, I can't find what kind of retracker is applied in L2 SARin mode data. As far as I checked, the low-resolution mode(LRM) was retracked by both of OCOG and CFI retracker. Is this same to SARin mode data?

Dear

Could anyone please let me know the procedure of making fine resolution DEM from CARTOSAT image. I would be happy even if you can help me to send relevant literature to prepare DEM. 

My objective is to check the impact of LU/LC change on runoff.

The positioning coordinate of a laser footprint is decided by many factors, not only including the location and attitude of satellite platform, but also laser ranging. Before the lauching of a satellite laser altimeter, how do you build up the model to describe the impact of these factors?

With some specific references/formulae.

Like Jason can give about oceans.