- Hai Liu added an answer:11Any remote sensing technique to map sub-surface objects(i.e, buried tiles in crop field)?
I am trying to delineate agriculture tile drainage in Midwest. I wonder if anyone has come across with GIS and sub-surface remote sensing techniques to detect tiles/objects buried in shallow depth of soil. Does anyone have any suggestions as to what type of remote sensing can be used to detect subsurface features? I can think of GPR (ground penetrating radar). Any other suggestions would be appreciated.
Thanks in advance !
Hi, Here I suggest a successful GPR application in locating a buried drainage structure at a depth of 70cm for your reference.Following
- Ali Reza Nasiri Khaneghah added an answer:5How do you change the pixel size of an image using Erdase or GIS?for a landsat image.
Dear Safinaz Ali
The software Erdas using yellow marked areas that can be changed pixel size (Attached image)Following
- Diego Garcia added an answer:12Is it possible to do dark object subtraction for Landsat 8 images in ArcGIS 10.2v?
I am using Landsat 8 images in my MSc research. Since I am new in the field of remote sensing, I don't know how to do it. The software that I am now getting familiar with is ArcGIS. I have tirelessly searched for solutions but with no success.
Any help on this will be invaluably considered.
I am trying to perform an automatic way of process Landsat 8 from DN to surface reflectance. One of the 'pains' have been to get the kl value automatically, because I refused to use the minimun value of the whole scene.
So what I finally did was to get a DTM (I have to cut a bigger one with the extension of the current scene, because is not always the same) and run Fmask (https://code.google.com/p/fmask/) whit throws a very good water mask (and cloud, cloud-shadow, snow-ice, and clean terrain pixel).
Once I get these two rasters (Hillshade and Fmask) I masked every band getting only the values within the terrain shadows and water bodies, then I choose the minimun of these masked values as the kl value.
For me, this would be correct, but I'd appreciate it if someone could let me know its opinion.
Ps. The python code for this is here: https://github.com/LAST-EBD/Protocolo/tree/master/Metodos/Get_kl_cswFollowing
- Gary R Olhoeft added an answer:6What would be the best portable device to look for concretions and rocks underneath a salt marsh?
The diameter of the concretions and rocks are ~ 10 to 20 cm at depth of 1 to 3 meter under a salt marsh environment. The salt marsh sediment generally has very high moisture content with 30% of clays. Attached is the photo of the salt marsh environment.
You need an acoustic echo sounder at least 10 kHz in frequency, preferably higher.
These are commercially available and your choice will depend upon how you intend to power and deploy it. They are sometimes available for rent.Following
- Emilio Ramirez-Juidias added an answer:1Can anyone please assist me in choosing the appropriate window size when estimating depth to source magnetic rocks using SPI method?
for example a data of an area of 55 by 55 km with sample interval of 100 meters
I attach you two important documents for you work.
- Kishan Singh Rawat added an answer:9Does anyone know a good source of potential evapo-transpiration (PET) data?
I'm looking for a time series of daily potential evaporation (PET) values that covers the UK area during 2012 - 2014. This needs to be at medium-high spatial resolution e.g. something like 1km grid or smaller. Preferably it would be calculated using Penman-Monteith for grassland or arable land cover types.
u can chack this linke:- cgiar-csi.org thay have global PET databaseFollowing
- Kishan Singh Rawat added an answer:8Does anyone know of a global Digital Terrain Model of the seabed?
I have found some DTMs for land but not for the oceans...
u can use cmap S/W, and extract DTM of seabed of your areaFollowing
- Cynthia Evangeline Sellinger added an answer:26What is the best programming language for solar radiation data processing?
I just programmed macros in Excel, but I realize that sometimes (when the databases are very large and I would like to calculate many specific variables ) consumes many resources and computing time. I hear of people using Python, Fortran, C++, etc., but what is the best?
Interactive Data Language (IDL) works great for programming large data sets. Not only can you use the built-in statistical packages, but this language handles a large, matrix of information with ease.Following
- Abdur Rahman added an answer:11How to estimate yield of wheat using remote sensing ?
how i can design a research project using remote sensing to predict yield of wheat
Dear, Mr. Laston
To be able to estimate the harvest of wheat seems to me almost the same as the estimated harvest in my country. You can use remote sensing technology combined with field research. Some things that you need to master is:
1. generative and vegetative phase of wheat; the generative phase is usually marked by the growth of leaves and ovaries. In remote sensing techniques can usually be seen the reflection of the pixel values of the object / value (the natural color is usually marked with green color), on Landsat imagery can use a combination of the band 321, or 432 band.
2. Phase vegetative phase of maturity or wheat grain filling. on remote sensing technology is usually represented by the color yellow.
3. You can also using NDVI algorithms to estimate the harvest of wheat where NDVI formulated using Landsat imagery: (Band3 - Band4 / Band3 + Band4), provided that:
a. NDVI value is low (even negative) in the early crops (replanting of wheat).
b. High NDVI value during the generative because of high chlorophyll contains
c. NDVI values lower at harvest Wheat (wheat growth to the NDVI values shaped parabolic curve)
4. By using crop cutting experiments 2,5x2,5 or equal to 3 x 3 pixels (1 ha) carried out measurements in the field, then the production of wheat can be formulated using linear regression (Ordinary Least Square) as follows:
Production (Wheat) / Ton / ha = a (NDVI) + b
a = constant
b = Constants
- Emad J Akawi added an answer:8How I can extract (Identify) underground tunnel and historical artifacts buried in the underground by remote sensing methods?
i wanna identify underground tunnel and historical artifacts buried in the underground by satellite images (Thermal or RADAR images), but i don't know how to used this images and which method(s) could be used for this purpose.
just you can use the surface features to identify or expect a subsurface features as the differences in the top soil or rocks the difference of the wetness of the soil and the subsistence in the surface layers of the soil or the rock. but if you want to be sure you have to use the geophysical methods as GPRFollowing
- Federico Di Traglia added an answer:4Has anyone carried out an integrated study of a subplinian explosive eruption linking aeroacoustics to the various signals?
Plinian and subplinian style explosive eruptions are aeroacoustic emittors. They radiate infrasounds. The aeroacoustic emission and spectral content is related to the physical parameters of the impulsively starting jet as well.
Aeroacoustic experimental studies suggest that turbulent jets can change their dominant aeroacoustic noise emission in response to a forcing vibration such as ground vibration or excitation by wind or as a result of changing vent geometry. This is also the basis for aeroacoustic noise reduction from the jet engines of jumbo jets.
In turn, these studies suggest that a lock-on effect, a sort of resonance may set in.
When it does entrainment is increased by up to 30% according to experimental studies on aeroacoustic forcing and turbulent jets and this, in the case of particle-laden turbulent jet flows, can influence mass distribution and particle ejection and reduce the mass loading in the turbulent and increasingly dilute jet flow.
Conversely, if aeroacoustic excitation is not at the resonance dominant frequency mode, entrainment may be reduced by up to 30% and in the case of an explosive eruption jet one may anticipate that this may result in a sudden change of style into fountain collapse. Particularly in the case where the mass flow rate is such that the eruption column is in the transitional regime, that between the stable plume and the collapsing fountain regimes.
Because an external excitation (noise intensity) of 1 in a million of the characteristic jet noise intensity may result in lock-on or the opposite, this may lead to the possibility of artificially modulating the entrainment and eruption style of some explosive éruptions.
That is to a partial external control, potentially, on the evolution of some explosive eruptions, given the means to do so (eg. 3 "jumbo jet" or "anchored missiles" arranged in a triangle around the erupting volcano, as aeroacoustic external sources of forcing).
To my knowledge this has not been studied either by doing any field tests, which is understandable or by studying this possibility using analogue particle laden jet systems in the lab with the view of applications to volcanic eruptions.
I am wondering if anyone has carried out integrated time-dependent studies of subplinian style explosive eruption jets (eg. at Sakurajima or Etna ?) with the view of assessing potential correlations between aeroacoustic emissions by the jet itself, time-dependent jet video images, radar/sodar imagery, continous volcanic gas flux monitoring (eg. DOAS), ground tremor characteristics, time-dependent wind intensity and/or obvious changes in vent shape over time ?
Looking forward to any info that may relate to this.
With best wishes and kindest regards,
did you see these papers?
Hope that helps
- Gamal Seedahmed added an answer:4What are problem statement regarding object classification and recognition in image processing with openMP?
this is my general definition for dissertation work - 'image processing through openMP '.
I need give problem definition for my master degree research work. I have very less knowledge about image processing. In my research work, apply openMP (parallel library) on image processing algorithm for reduce time consumption.
Mainly I want to know about object classification algorithm or methods for remote sensing data or images.
Please suggest me some algorithm, so i can apply openMP library for make them parallel.
The problem statement is:
Given a set of images and prior knowledge about the content of the images find the correct Symantec label for the pixels in the image/s. Indeed, you need to go through the cycle of feature extraction/segmentation/training/.....
- Jagath Rajapaksha added an answer:5How can I monitor the flood over a river during monsoon season with thick cloud patch in satellite image?
I know SAR imagery is good one...but its resolution is very poor.
ALOS2 PALSA2 has better resolution (10m) and you may contact Sentinel Asia for ALOS PALSAR. It has HH, HV, VH, VV. I recommend HV polarization for flood detection using change detection method.Following
- Falah Fakhri added an answer:16Has anyone worked with Sentinel-1 C-Band Synthetic Aperture Radar (SAR) satellite data in the context of Natural Hazards & Disaster Risk Management?
Although there are some RADAR based sensors out there which are quite helpful in Emergency and Disaster Response situation, they are not freely available. Now it seems Sentinel-1 is the first one which I know is free! The answer to a cloud free day and night Satellite Imagery is finally here. I would like to know how Sentinel-1 C-band Synthetic Aperture Radar (SAR) which builds on European Space Agency’s and Canada’s heritage SAR systems on ERS-1, ERS-2, Envisat and Radarsat can be used for Natural Hazards and Disaster Risk Management, especially in Flood situations.
'Sentinel-1 carries an advanced radar instrument to provide an all-weather, day-and-night supply of imagery of Earth’s surface. As a constellation of two satellites orbiting 180° apart, the mission images the entire Earth every six days. The mission will benefit numerous services. For example, services that relate to the monitoring of Arctic sea-ice extent, routine sea-ice mapping, surveillance of the marine environment, including oil-spill monitoring and ship detection for maritime security, monitoring land-surface for motion risks, mapping for forest, water and soil management and mapping to support humanitarian aid and crisis situations.'
Kindly support your answers with relevant research papers.
- Diana Patricia Lozano Zafra added an answer:4How can I find the relationship between glacial geomorphology and groundwater, using remote sensing and terrain analysis?
Right now I am working on a project with the Bogota Water Company. This company is in charge of water supply for the entire city of Bogotá. The water is taken from Chuza River basin, that is located in Chingaza's paramo. Paramo ecosystems are intertropical montane ecosistems located between 3200 meters above sea level and 4000 meters above sea level, with temperatures ranging between 2C and 17C, the mean annual temperature is 10C. In Colombia, all paramos are located on old glacial landscapes .
The project is about understanding what could happen with the water supply under global warming conditions.
From some fieldwork observations as well as aerial photographs interpretation, I could infer that glacial deposits offer the mot suitable geoforms for water catchment, and water infiltration. Glacial deposits have a high rugosity which is evidenced by the presence of a lot of depressions that concentrates water in small and swallow lakes similar to wetlands. I would like to produce a model, that gives me the water catchment susceptibility and water infiltration susceptibility in terms of geomorphology.
In order to solve this issue, I would like to know if anyone can help me with articles, techniques, methodologies regarding the evolution of glacial and periglacial geoforms under global warming, and regarding the relationship between glacial geoforms and water catchment, as well as glacial geoforms and water infiltration.
I would appreciate any information,
Thank you Dmitry even though my study area doesn't have any permafrost that can generate thermokarst morphology.
- Shashi Gaurav added an answer:7Can someone explain about delineation of lineament in volcanic geomorphology?
i have research about groundwater potential zone in Mt. Merapi , Indonesia.
Lineament is easy to found at structural geomorphology but its so hard to find at volcanic (break of slope)
Remote sensing data for this research: ASTER GDEM and LANDSAT 8 (both 30 meter)
Remote sensing technique: Filter directional+High Pass+Low Pass, Principle Component Analysist
Result: Directional phenomenons could be found such as roads,etc. but lineament is not yet
Detection of lineament in volcanic area is relatively tough rather than in the normal area. Instead of using Aster GDEM try using SRTM 30M DEM. Since you are using the Landsat 8 Images, you can try Filter directional+High Pass+Low Pass, Principle Component Analysis with different bands as there different band available. Bands 6 and 7 cover different slices of the shortwave infrared, or SWIR. They are particularly useful for telling wet earth from dry earth, and for geology: rocks and soils that look similar in other bands often have strong contrasts in SWIR. Try using false-color image by using SWIR as red, NIR as green, and deep blue as blue, It may help you. Aslo SRTM 30M DEM can help in identifying the lineaments as it has been prepared from the radar images and due to the scattering properties lineaments and fractures are better recorded in radar images.
Good luck for your WorkFollowing
- Hayder Dibs added an answer:3Sentinel 1 IW mode: how to correct radiometric variation between sub swath ?
In the goal to make mosaic of IW Sentinel 1 mode over Guiana Shield, I used Snap (or Sentinel 1 tool box) to process GRD product using the following step:
- Multillooking 2x2 to reduce image size and reduce ram use
- Terrain Flattening (default value)
- Terrain Correction.
At last I convert the 2 polarisation in dB and I build a new channel equal the vhdB-vvdB in order to to the folowwing color composition: R vvdB, G vhdB, B vhdB - vvdB
So, when I put all this data in Qgis and when I adjust the display stretch in order to have exactly the same min and max I obtain results shown in screenshot.
As you can see there is radiometric variation between sub swath in each data (in particular between the first 2 sub swath and the third).
I know that incidence angle have variation but I am convince that it's possible to correct this effect.
However I don't know how to do it easily.
So my question is did you know how to correct this effect ?
Thanks in advance.
Dear you need to do relative radiometric correction and you can use many different approaches, such as mean filter Histogram adjustment and another.
- Adolph Nyamugama added an answer:11Is there any way to acquire free WorldView imagery for scientific research?
I am intending to start a new research and I need very good spatial resolution imagery, therefore I am searching for websites or other sources that offer WorldView imagery for free, does anyone have a hint?
Yes there are various you can also try sentinel products,and.copernicus.vgt.vito.be/PDF/portal/Application.html#HomeFollowing
- Rasit Abay added an answer:4How do I simulate ground track for NASA's SMAP spacecraft ?
The SMAP orbit is a 685-km altitude, near-polar, sun-synchronous 6am/6pm, 8-day exact repeat, frozen orbit.SMAP’s most prominent feature is its large spinning instrument antenna. When the antenna spins, the spot(40km diameter) moves in a circle 1000 km (620 miles) in diameter around the observatory – this forms the very wide measurement swath of the instrument that is key to enabling SMAP to measure the entire Earth every 2-3 days (depending on latitude). More on http://smap.jpl.nasa.gov/observatory/specifications/
Since I prefer open source programs, I recommend that you use NASA's General Mission Analysis Tool (GMAT) or Java Astrodynamics Toolkit (JAT). Moreover, if you studied astrodynamics before, you can also use OREKIT, a low level spaceflight dynamics library, (which is tested for real missions) and CESIUM, stand-alone virtual globe program, for determining the trajectory and visualization respectively.Following
- Imran AHMED Khan added an answer:6How can I find out micro-scale soil moisture remote sensing data along with rainfall, soil temperature and evapotranspiration data?
I want to assess soil moisture role on vegetation dynamics and ecology.
Moreover, Some additional modelling with flooding and drought conditions in Pakistan.
Many thanks Giacomo.Following
- G. Caniaux added an answer:7What is the best method of statistically comparing two non-parametric data distributions?
I have 2 different laser scanning systems observing the same target, and each system observes and records a full waveform 'intensity' profile. Profiles recorded by each system may be similar or different, based on a number of variables.
Given neither profile is likely to conform to any predefined distribution (i.e. Gaussian, Poisson, etc.), and that each profile has the same number of observations, what is the best way to quantify if they are statistically similar?
First, test your distribution by using as recommended by Alessandro and Rudolf the Kolmogorov-Smirnov.
Second step: try to test the homocedasticity of your samples (i.e. the homogeinty of the variance) by using the Bartlett's test, or Levene's test (an alternative form being the Brow-Forsythe test where the mean of the Levene test is replace by the median).
If these tests are positive, you can use parametric tests for comparing you samples (among them, the Student's mean for comparing 2 samples, ANOVA test for several samples of inequal size).
If not, then use a non-parametric test: for instance a Mann-Withney Wilcoxon, Wilcoxon range (for comparing two sample), Friedman's test (for several samples fo the same size) or the Kruskal-Wallis test (several samples of inequal size) .
Hope this can help!
- Rafael Angel Rebolledo Wueffer added an answer:10How can I calculate ecosystem vigor by using RS and GIS?
Is there any method to obtained the vigor of ecosystem in simple way?
What is the most applicable method for Vigor calculating by Remote sensing and Geographic Information System without Field measurement?
What factors influencing the vigor of ecosystem?
Ecosystem means diverse elements, each of them have particular "vigor" indicators, for example: from RS: NDVI for plants, Chorofile A for ponds, etc. You can also prepare Indicators based on GIS for primary productivity, resilence and health odf some features. I mean that a Ecosiystem vigor could be a summary of all these indicators.Following
- Georgi Stoimenov added an answer:26How to monitor/estimate soil moisture over large areas?In situ measurements only provide soil moisture estimates for small soil volumes (~1 m²) and satellite data are nowadays operational only at coarse spatial resolution (>600 km²). However, for many applications we need soil moisture observations at an intermediate scale. How to fill the gap?.
For large areas soil moisture will be very different, average evaluation can be done measuring the plant water stress by infrared thermometer.Following
- Dweependra nath Kalita added an answer:3What could be the hydrodynamic and morphological modeling strategy for the braided rivers with limited bathymetry information ?
I have been trying to understand morphological dynamics of the Braided rivers (Brahmaputra) using 2D/3D models. The main hurdle is the unavailability of detailed bathymetry information for braided reaches of the river. When I use 2D models such as CCHE-2D, it frequently crash when simulated with coarse bathymetry data. Is there any way I can improve my modeling strategy to get better results over the Braided reaches using remote sensing or any other information.
River cross-sections across the Brahmaputra from Pasighat to Dhubri taken at 10 years' interval may be available with the Water Resources Department of Govt. of Assam. That may help in developing the mesh of desired resolution required by your software. If 3/4 sets of data spanning 3/4 decades for your concerned stretch of the river can be collected, it can be helpful to understand the complex morphological dynamics of the Brahmaputra. I am not sure if by limited bathymetry information you mean that you are already in possession of the said data. From the data-availability perspective, bathymetry data is more critical than the other two elements affecting the morphological dynamics of a braided river viz. flow and sediment.
The remote sensing alternative would be to go for Bathymetric LiDAR data which, I am afraid, may not be readily available.Following
- Jibran Khan added an answer:2Difference between ASAR Wide Swath and Alternating Polarization for vegetation monitoring?
Can someone please elaborate the difference between ENVISAT ASAR Wide Swath (WS) data and ASAR Alternating Polarization (AP) data such as HV or VH when they are used for vegetation monitoring for the region of interest?
Thank you Dibyajyoti for your feedback.Following
- Closed account added an answer:4Anyone aware of any research, published / unpublished, in any language; over the usage of spectral signature to trace/track/locate living organisms?
I am interested in any scientific research, whether published or unpublished, in any language at all, that has tackled the issue of usage of spectral signature (of any kind) in order to trace / track / locate / position any living organism, whether humans or else. Any credible information will be highly appreciated.
Your answer is crystal clear, but it's relevant to GPS/GNSS not spectral signature. Remote sensing is a general term and as you know there's GNSS-based remote sensing now, and many even consider Lidar and Photogrammetry as types of RS... but I am highly specific on the RS I am after: based in spectral signature of any kind.Following
- Mark Brown added an answer:16Has anyone used small UAVs to monitor bird colonies?I am now thinking of using a small remote controlled helicopter like an ardrone outfitted with a hd camera and GPS to document the start of nesting and to get a count. The islands are small, wide open, have low vegetation, the chopper has a very low noise. Not sure how the birds will react.
We used two types of drones on Kelp Gull colonies in South Africa. A silent fixed wing "glider" worked well, but the quad copter was too noisy and caused too much disturbance. Glider worked well, had a few non-incubating birds follow it, but most incubating birds ignored it...Following
- Rabia Tabassum added an answer:4How to use SEBAL model for evapotranspiration?Any software needed to run it, or just equation can be solved to find values for evapotranspiration?
By using remote sensed data (satellite images) evapotranspiration can be calculated with the help of Arc GIS software. see this link
- Jared Keyes asked a question:OpenCan anyone help me find bathymetric river data for the Philippines and/or Indonesia?
Dear ResearchGate community,
I have searched online and contacted the proper ministries/organizations, and looked into the possibility of finding river depth through remote sensing techniques (Ex. LiDAR) but have found nothing, and was just wondering if anyone could help me out.
Thank you in advance for your time and attention,Following
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