Questions tagged [remote-sensing]

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

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2
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1answer
90 views

Can I regard the grayscale of a RGB color image as a panchromatic image?

Here I have a remote sensing dataset with many bands (e.g., blue, green, red, ...), and I use the blue, green and red bands to get a true color image. I want to know if I can get a panchromatic band ...
1
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1answer
58 views

Is there any intuitive and easily understandable way to help students understand the triangular facet of outcropted stratigraphy?

I find it difficult to teach college students about using the triangular facet on remote sensing images to judge the dip direction of sedimentary formations. Is there any intuitive way that can help?
2
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1answer
59 views

How can we distinguish fold and cycle of sedimentation on a remote sensing image or in the field?

A fold is composed of stratigraphy that is symmetric and repeated. Cyclic sediments (also called rhythmic sediments) are sequences of sedimentary rocks that are characterised by repetitive patterns of ...
3
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1answer
77 views

Free periodical satellite/aerial imagery

There is a company called Planet Labs which sells daily satellite imagery covering the whole globe that can be used for various research like agriculture, forestry etc. I wonder if there is a free ...
2
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1answer
52 views

Is there a name for a type of algorithm or processing which uses only one source of data as input?

Many algorithms in remote sensing take one or more different datasets as inputs and return some output. An example might be computing the amount of sulfur dioxide (SO2) injected into the stratosphere ...
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0answers
22 views

Where can I find canopy reflectance data for crops (soybean in particular) for different dates across the growing season

I have been trying to find literature values for reflectance of soybean for different dates along the growing season (I am specifically interested in 30, 60 and ~120 days after planting - so the V3/V4 ...
3
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0answers
58 views

Lead remote sensing?

I am trying to formulate a research topic centered around the environmental effects of general aviation's continued use of leaded gasoline (containing tetraethyllead) to power piston aircraft. In ...
6
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1answer
345 views

How to convert mol/m^2 to total mass ( e.g gram, kg etc )?

I want to calculate the total $\rm{NO_2}$ amount in a year using satellite Sentinel-5p NO2 dataset. But the problem is sentinel satellite data stored in $\rm\frac{mol}{m^2}$ unit. But I have to ...
2
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1answer
99 views

Landsat 8 acquisition time and date

The the meta data text file that comes with Landsat scenes, contains an acquisition date and a scene center time in successive lines. I wanted to know if the image is recorded at the scene center time ...
4
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1answer
151 views

What is the use of HV or VH polarization in Radar?

Radar is a common tool in remote sensing, it is a so-called active instrument, hence it emits and receives energy. Modern Syntethic Aperture Radar (SAR) systems are capable of both transmitting and ...
0
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0answers
34 views

NDWI from Landsat 8

I have layer stacked Landsat 8 image, how can I calculate Normalized difference water index (NDWI) from it? I would have been able to calculate it easily using the raster calculator, if I had the ...
2
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0answers
27 views

Planetary Reflectance vs Relative Spectral Response

I am confused between a Planetary Reflectance and the Relative Spectral Response (RSR). What I know/guess is that RSR is a response/function of an Instrument band's reflectance against a spectral ...
8
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3answers
194 views

How do the pros measure humidity?

I have used a wet/dry bulb setup to estimate humidity, and it appears that the Argentinian meteorological service uses one in Antarctica as well. Wikipedia sez: Humidity measurement is among the ...
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0answers
53 views

District/province wise air quality data for South Asia (2010 onward)

I would like to create a district/province-level air quality data for all the countries in South Asia from 2010 onward using satellite data. As someone with absolutely zero background in remote-...
4
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2answers
200 views

What are the differences between down-looking and side looking radar?

In Radar concept the SAR-Synthetic Aperture radar performs as side-looking to collect information, why it is not downlooking? There are down-looking radar also. So what are the differences between ...
2
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0answers
33 views

Pansharpening of Spot 6 image

Would the pansharpening of Spot 6 work on the NIR band? Since the wavelengths captured by the panchromatic band does not overlap with the NIR band. The band designations are in the attached image.
0
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0answers
44 views

Google earth historical imagery date

I am working on a small creek in Colorado using historical imagery via Google earth. I want to know if the imagery date at the bottom of each image on google earth is the date the google acquired the ...
2
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0answers
20 views

What is the meaning of nomalized difference Built-up index?

I know how to calculate it by remote sensing image, but why do we define this? What can we know about a remote sensing scene by this indicator? What's the connection between normalized difference ...
1
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1answer
34 views

Regional and Relative Sea level

I am a little confused by the terms "regional" and "relative" in the sea level change context. Do the two words have the same meaning? Does the "regional MSL trend" in https://www.aviso.altimetry.fr/...
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0answers
44 views

How to transform level 2 satellite retrievals to level 3 gridded data

Usually, I use level-3 gridded satellite data to analyze the spatial and temporal patterns of atmospheric compositions. However, there were some data sources which only afford level 2 product. For ...
2
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0answers
20 views

What (if any) “in-situ instrumentation” is on the Brunt Ice Shelf that will detect its splitting and breaking away?

The BBC News article Antarctic: No role for climate in Halley iceberg splitting says: With no-one on the ice surface, notice of any breakaway will have to come from automated in-situ ...
7
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1answer
193 views

Public sources of topographical data of Earth?

I would like to find sources of topographical data for Earth's surface. I've looked in GIS SE and Open Data SE but haven't found a good answer to this so I though I'd ask here in Earth Science. Are ...
1
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1answer
47 views

What is the most real-time method of determining SPI?

For drought monitoring related to vegetation, I need to calculate Standardized Percipitation INdex for a given area. Where can I find the most real-time percipitation data to do this? The best I've ...
2
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1answer
59 views

Where can I find archived night microphysics images from EUMETSAT? I

I want night microphysics RGB composite from EUMETSAT. I'm looking for archived images. I tried finding them on EUMETSAT's data center page. Data from different channels of SEVIRI is available but ...
1
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1answer
403 views

How to extract lat-lon from MOD10C2 hdf data in matlab?

We can import and read all given bands/parameters of MOD10C2, lat and lon is not given as separate band rather embedded with other bands. How we can extract from MOD10C2 hdf data in matlab. Similar ...
1
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1answer
98 views

How to figure the MODIS snow cover against different elevation zones?

I am working on MOD10C2 (8days snow cover), when I clip the MODIS snow cover against different zones of elevation the results was against general trend .i.e. the higher elevation was showing lower ...
0
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1answer
55 views

Artefacts in PERSIANN-CCS data

I downloaded PERSIANN-CCS for the region of Pawlowdar, Kazakhstan and this has stripes all over my downloaded data. For another AOI in Kazakhstan I do not have this problem. Does anyone of you have ...
6
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1answer
501 views

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 ...
1
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1answer
75 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?
7
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2answers
609 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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0answers
28 views

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?
10
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2answers
201 views

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 $NH_3$-...
4
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1answer
41 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 ...
6
votes
1answer
129 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 ...
7
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2answers
569 views

How do optical satellites detect different leaf types?

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 ...
2
votes
1answer
76 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....
4
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0answers
146 views

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, ...
5
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1answer
126 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 ...
2
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1answer
403 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.
1
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1answer
104 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 ...
8
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1answer
378 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 ...
3
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2answers
109 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 ...
1
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0answers
80 views

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 ...
5
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2answers
184 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 ...
3
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2answers
138 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 ...
6
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3answers
1k 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? COD: Chemical Oxygen Demand BOD:...
19
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3answers
7k views

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 ...
7
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1answer
191 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 ...
4
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0answers
126 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 ...
4
votes
1answer
80 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 ...