Questions tagged [remote-sensing]

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

Filter by
Sorted by
Tagged with
6
votes
1answer
123 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 ...
1
vote
1answer
30 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
votes
1answer
81 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
votes
0answers
26 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
votes
0answers
19 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 ...
7
votes
3answers
166 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 ...
1
vote
0answers
42 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
votes
2answers
100 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
votes
0answers
27 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
votes
0answers
35 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
votes
0answers
19 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
vote
1answer
31 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/...
1
vote
0answers
35 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
votes
0answers
19 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
votes
1answer
158 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
vote
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
votes
1answer
47 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
vote
1answer
307 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
vote
1answer
88 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
votes
1answer
52 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
votes
1answer
274 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
vote
1answer
63 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
votes
2answers
464 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, ...
1
vote
0answers
27 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
votes
2answers
185 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
votes
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
118 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
votes
2answers
469 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
72 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
votes
0answers
131 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
votes
1answer
119 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
votes
1answer
368 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
vote
1answer
100 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
votes
1answer
360 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
votes
2answers
108 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
vote
0answers
77 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
votes
2answers
161 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
votes
2answers
127 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
votes
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
votes
3answers
6k 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
votes
1answer
189 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
votes
0answers
125 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
72 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 ...
3
votes
1answer
1k 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 ...
5
votes
1answer
321 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 ...
4
votes
1answer
456 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: ...
12
votes
2answers
306 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 ...
3
votes
0answers
43 views

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 (...
2
votes
3answers
3k 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 ...
3
votes
1answer
79 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. ...