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Questions tagged [remote-sensing]

Questions about measurements which are taken from remote locations / are not taken in situ.

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CO2 fertilization factor for estimate increases in biomass

Is there some factor or equation (derived from some paper) that we can multiply in the tropical forest biomass in current condition to estimate co2 fertilization effect in future (e.g rcp8.5 scenario)?...
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Why is satellite imagery data delivered as signed 16 bit integers?

Landsat 5 tm reflectance product images are delivered as signed 16 bit images, why is this preferred to unsigned 8 bit that the DN's are stored as level 1 products for the same satellite? Look at ...
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1answer
41 views

Satellite image displaying as panchromatic

I have a 4 band image (Blue, Green, Red and Near Infrared). If I display my image with only the green band in the RGB channel, the image displayed is panchromatic. Why is that?
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101 views

How does ice-penetrating radar “see” through kilometers of ice without being absorbed?

The BBC News article Isolated lakes found beneath Canadian ice sheet links to the open access Science Advances article Discovery of a hypersaline subglacial lake complex beneath Devon Ice Cap, ...
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Detecting the hydrothermal alteration zones?

Is it possible to use remote sensing to determine Hydrothermal alteration zones without resorting to collecting samples from the Area of study?
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2answers
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A rough picture about the ground-level ammonia (NH3)

Ammonia is the only alkaline gas in the atmosphere. It is one of the key features to control the acidity of aerosols and the formation of ammonium salts. In the environment of $NH_3$-rich and $NH_3$-...
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1answer
31 views

What is an 'obstacle vista diagram'?

Currently I do some research about SODAR and at this paper, the author wrote (p. 1502f): A site should be relatively clear of obstacles that could act as potential fixed-echo reflectors. If that ...
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1answer
74 views

Are there standards for tropospheric NO2 levels considered low or high?

I'm working with Ozone Monitoring Instrument (OMI) $\ce{NO_2}$ vertical column density (molecules/cm2) data. To help interpret the values, I'm wondering if there are standards that show which values ...
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132 views

Can we determine leaf type (broad leaf or needle leaf) from NDVI?

In various land cover classification systems, trees are also categorised on the basis of broadleaf or needleleaf. Can someone please tell me the mechanism through which satellites detect this leaf ...
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42 views

Using NASA's radiance calculator to make a graph to find the where the peak radiation emission are?

I am trying to graphically show the radiance emissions of both the Sun and Earth. I am using NASA's radiance calculator then going to graph it on paper. Here is what I typed in: Low wavelength: 0....
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How to read EUMETCAST GOME-2 data?

We receive EUMETCAST data with different formats in our local station, I am having the most difficulty when trying to read or sometimes even know the format of a specific data product, in this case, ...
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62 views

Satellite ocean near-surface air temperature data

For my study, I need to use satellite Sea Surface Temperature (SST) and at the same time I also need satellite air temperature data (Ta) for the first few meters above the ocean. For SST I'll be ...
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1answer
91 views

Understanding pushbroom sensors

Does a push broom scanner scan a path perpendicular to the direction of satellite travel? I am confused because its detectors are arranged across track even though it scans along track.
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1answer
64 views

How to get single value of NDVI value from four different directions?

I have a data set which contains NDVI (Normalized Difference Vegetation Index) values of four directions (NE, NW, SE, SW). Now, I would like to have single value which considers all 4 directions. Is ...
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1answer
252 views

The giant 6,000 km$^2$ iceberg A-68; will ground-truth telemetry supplement satellite tracking data?

update 2: FIRST images of A-68 iceberg not taken from a satellite in space but from the air are out. On this NASA Earth Observatory web page are areal images from NASA's Operation IceBridge taken from ...
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2answers
82 views

Odd Inuksuk-like objects

I found some huge objects that are way too big to be inuksuks, in my opinion. The object on the right is very odd because the arms are not straight like they are in most images of inuksuks. and ...
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Calculating band depth image for M3 data

I am working with chandrayaan M3 hyper spectral data. I need to create a band depth image for identifying mineral abundances. How do i calculate the continuum reflectance value for producing a band ...
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2answers
101 views

MODIS Surface Reflectance Data State QA Aerosol Quantity field meaning is unclear

I am trying to compare NDVI values computed from MODIS Surface Reflectance(MOD09) with the NDVI product (MOD13). MODIS Surface reflectance Collection 5 products include a Data State QA field that I ...
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2answers
92 views

What is a breadboard (retrieval) algorithm in the context of geophysical satellite retrievals/remote sensing?

In a recent met-jobs job posting (different version here) for a researcher with a background in climatology/meteorology/hydrology or environmental sciences, I saw the phrase breadboard retrieval ...
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357 views

Can you measure BOD/COD real time using any sensor?

There is a requirement to measure BOD/COD in a wastewater treatment plant in real time. Is it possible? And if so are there any sensors available in the market for it?
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Why clouds are not moving in NASA's video of the Moon passing in front of the Earth?

I recently saw a short video from NASA. It shows the moon passing by the Earth as it rotates. NASA link: From a Million Miles Away, NASA Camera Shows Moon Crossing Face of Earth. The video itself ...
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1answer
115 views

Need help understanding this satellite image of Larson C ice shelf

The false color image below shows synthetic aperture radar imaging from ESA's Sentinel-1 satellite. The map from the 20-Jan-2017 BBC article Larsen ice crack continues to open up illustrates the same ...
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109 views

Software and methods used in LIDAR data visualization?

I was assigned a task to prepare a report which states the current state of the art in Doppler wind LIDAR (DWL) visualization and visualization tools used in meteorology. In the last 3 days I've tried ...
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1answer
59 views

The higher value range for the same satellite product (NO2_OMI_TEMIS)

I'm dealing with NO2 column density of troposphere, and my data source is TEMIS. The NO2 level3 data can be derived from the original information of OMI instrument. I have downloaded two types of ...
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1answer
404 views

Convert OMI NO2 Vertical Column Density (molecules/cm^2) into Mixing Ratio (ppm)

I want to convert OMI AURA data on NO2 column amounts in molecules/cm2 into ppm for comparison purposes with other literature. Can it be done? Is there a standard way of doing it? I looked into the ...
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1answer
255 views

What is principle of inverse modeling?

I read a few paper related to emission inventory talking about the inverse modeling. It was another method to estimate the emission from ground(called top-down ...
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1answer
391 views

Methane remote sensing?

I'm trying to compile a list of remote sensing (Earth observing satellite) instruments capable of detecting methane in the atmosphere or near surface of Earth. After some search I have found: ...
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195 views

How to remove 'silk braid' noise in satellite data?

Satellite remote sensing data is a powerful tool for researching the spatial distribution and temporal variation of atmospheric species. Aura is one satellite owing to NASA which meaning ...
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Conversion factor between different Landsats?

I have collected data (spectral bands) from Landsat 4-5 and Landsat 8. I was calculating NDVI when I noticed that the two Landsats have different band numbers designated as Red and Near Infra Red (...
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3answers
2k views

Difference between Meteosat and Insat satellite Images

I have seen many times that their are two kinds of Satellite Images shown on the websites like Skymet for India i.e. Meteosat satellite images Insat satellite images I want to understand the basic ...
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1answer
64 views

GIMMS NDVI3g grid cells not entirely square-shaped?

The official data description of the recently updated GIMMS NDVI3g record describes the grid parameters of the dataset as follows. ...
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1answer
384 views

How do weather services measure wind

I'm curious to know where commercial weather services like the Weather Channel and Weather Underground get their wind speed and direction measurements, to produce maps like this one (http://www....
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1answer
81 views

High resolution DEM for digital soil mapping and modelling

I am carrying out an exercise on digital mapping of soil properties. I have tried several high resolution DEMs like 90 m and 30 m but their resolution is not good enough. Kindly assist.
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2answers
116 views

Need help understanding variables that relate to meterology terminology

I am working on a project in predicting the weather and I had a few brief questions. I understand that radar works by bouncing waves off of precipitation and measuring reflectivity. I have a variable ...
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1answer
48 views

What is the technical term for spatially aggregated measures?

Is there an adjective to describe data that has areal weight, like area, biomass, population, etc. — data that has to be aggregated by sum for example — vs. data that doesn't, such as landcover ...
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74 views

Observations of sea ice typology in the Arctic

What are the main datasets characterizing sea ice typology, thickness, density, "passability", presence of pressure ridges in the Arctic? Is it something that can be detected from the air or a space ...
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1answer
75 views

Remote Sensing System (RSS) historical atmospheric data continually updated

Does anyone know why every month there are updates to the RSS historical atmospheric data? How can data that is 10 years old need adjusting every month? For instance, here's the difference in data ...
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71 views

Spatial variability in ocean surface winds

For the near-surface winds over the ocean, many model products and satellite footprints have spatial resolutions on the order of tens of kilometers. I'm interested in knowing how much the winds (both ...
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1answer
479 views

Should Modis & LandSAT NDVI composites agree and why not?

Modis takes daily images at coarse resolution (500m?) that are then lumped into 16-day composites. LandSAT, let's say 8, takes roughly bi-weekly images at 30m (100m resampled to 30), and those are ...
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1answer
1k views

How to count lightning in a thunderstorm?

Is there an accurate way to count the amount of lightning happening in a thunderstorm? How is lightning measured? Is there a special unit for this?
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1answer
226 views

What is the purpose of this large structure on a Japanese hillside? [closed]

A Google satellite view shows an unusual structure on a hillside in Miyazaki Prefecture, Japan (Latitude 31.782600°N, Longitude 131.233881°E): It measures about 170m by 120m and is structured in ...
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2answers
1k views

What color is the Sahara desert, as seen from orbit?

In images of the Earth taken from spacecraft (or composite images thereof), the color rendering seems to be really inconsistent. Examples (Source: NASA, http://visibleearth.nasa.gov/view.php?id=...
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245 views

Predicting earthquakes using disturbances in DTH TV transmission

It is said that before an earthquake happens, a viewer experiences disturbances in DTH TV transmission in the form of distorted images on the screen which automatically correct after a few seconds. ...
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1answer
520 views

Locating Missing Airplanes using Remote-Sensing Satellites

The Maylaysian jetliner that went missing has yet to be found. There are many remote sensing satellites, equipped with radars, currently in service. Together, they provide good coverage of the entire ...
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437 views

What is a Geophysical Model Function (GMF)?

I have heard the term mentioned many times in seminars, and in papers on remote sensing. What does it mean? References would be helpful if available.
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177 views

TRMM rainfall measurement for synoptic systems

I have gone through the website of TRMM that explains how the TRMM satellite gather precipitation data- http://pmm.nasa.gov/node/158. During the Indian Summer Monsoon (ISM), we have synoptic systems ...
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179 views

NASA GLAS Lidar Data Format [closed]

NASA GLAS Lidar Data can be downloaded here. I cannot find (or perhaps understand) the answer to my question on the icesat/glas page. Lidar data can be provided as points (las) or raster (dem), ...
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1answer
268 views

What sort of instruments do planetary geologists use to predict that there are oceans on the moons Titan and Europa?

NASA Planetary Scientists released a video that says they have confirmed that there is an underground ocean in Europa and that Titan has liquid oceans made of hydrocarbons. I myself am an aspiring ...
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297 views

What are the advantages in looking at an OLR map versus looking at IR satellite imagery?

Conceptually they seem to be showing the same information. But in the context of a Madden Julien Oscillation (MJO) or equatorial waves especially over the equatorial oceanic layers which one is more ...
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Iowa State GOES Visible Data - misaligned EPSG:4326

The WMS server of Iowa State is serving data for the GOES-13 satellite in the visible channel. As best as I can tell, the data is misaligned with other data sources. For example, in a WMS client, ...