Its clear skies across the country , in early spring, perfect for that groundtruthing exercise you’ve been hopping to carry out. Since, unusually it seems we can rely on good weather for a few days we can plan ahead but how do you know when to do your groundtruthing in order to exactly coincide with your satellite of choice? You use a a “satellite overpass predictor” tool. Plenty on the web – the one I use at the moment is from NASA and predicts overpasss times for its EO satellites.
Here a map showing Terra satellite (for the MODIS instrument) overpasses tomorrow from the site
Note the times are in GMT, if you want wave at the satellite it’ll be overheard around 12.30 pm
The issue of soils and land use in agriculture is very hot at the moment. Lots of projects looking at these issues using remote sensing. Coming either from an environmental, often water quality approach, or from an agronmetric/extension approach, trying to improve outputs and profitability of irish farming ( for example the Harvest 2020 report). Sometimes an image pops up that really emphasises that ultimately we are heavily influenced by geography. Below is an image I’m using in a project looking at grassland and it really emphasies the effect of soil on short and long-term land use choices in farming.
Its a September 2009 Landsat TM5 image (Bands 3,4,5-rgb) in kilkenny-carlow region, with soil associations from the general Soil map overladen. The colours are not “true” colours – The general light green areas are grassland, the light pink is bare soil, the darker, lusher greens are forestry and deep russet red on the left are the exploited bogs, the built up areas of Kilkenny and Carlow show up are purple blotches.
Its a fascinating image we can see that the pink crescent stretching from Kilkenny to Carlow that the harvest is in – the fields are bare, but we can also see how that land use choice of tillage is determined by the soil type – the blue polygons are areas of grey-brown podzolics (light textured well-drained sandy loams) soils in this , where as the white polygon in the centre the association is dominated by gleys (poorly drained soils). So the poorly drained soils constrain the choices made – their physical structure is unsuited for tillage – but we can also see in play longer term landuse choices as the percentage of forestry in the gley area is much higher than the GBP areas. Though the forests would grow even better in the GBP areas, the economic return for the farmer favors tillage.
This article looks at remote sensing and horticulture, specifically potato growing. Is it impossible for this technology to be applied here? There are issues of scale and location (the high value seed potato crop is located in cloudy donegal for example). But in light of projections for climate change and there impact on potato cultivation in Ireland as a result of water stress – then its something we should consider.
I don’t often post such things but this time-lapse video taken from the ISS as it orbits the globe at night is astonishing. What a stunning view – the cities illuminated the auroras as a glowing shell flaring at the poles- the bright flashes of electrical storms. Best 3 mins you’ll spend to day