I agree... The worst thing that ever happened to NASA was all this "Mission to Planet Earth" nonsense (which we can mostly "thank" Sally Ride for... she proposed it as a way for NASA to continue to do "science" missions "on the cheap"-- it's cheaper and easier to launch stuff into LEO or even GEO rather than send probes out across the solar system to other planets, and FAR cheaper than manned missions of whatever type or kind).
Oh, there's a host of sensors (including the aforementioned near infra-red sensors that detect plant florescence and therefore measure photosynthesis and therefore indirectly measure "plant stress" but basically your right-- without a BASELINE of data to establish a "norm", there is NO WAY to extrapolate "trends" in the data, not without DECADES of observations to fall back on. Of course that won't stop the climate fear-mongers from deducing "trends" using very-short span subsets of data, and then pushing for LEGISLATION OR REGULATION to "combat these observed trends" as they see them. Remote sensing is getting to be big business in agriculture-- drones using NIR cameras can be programmed to overfly crop fields weekly and photograph them, so that the data can be use for mapping purposes for applications of materials to the crop (like fertilizer, water, or pesticides) BUT it takes someone ON THE GROUND to go out there and see what's CAUSING the "stress" detected in the photographs... this "GROUND TRUTHING" is the part that is TOTALLY MISSING from NASA's mission as described. Without the "ground truthing" of someone actually going out to determine WHY the crop is "stressed", there's really nothing that can be gained from the photography other than the fact that the "photos indicate the crop is stressed", which is the most you can REALLY say with any "certainty". Unless you know the REASON for the stress (is it insufficient fertilizer, or lack of water or too much water from insufficient drainage, or some soil issue tying up essential nutrients, or soil structure issues like compaction, or disease pressure, or insect pressure, or weed pressure, or some combination of all these factors, or exacerbating or compounding the stress or causing issues??) Until you know, it's really rather pointless, because you cannot make any RELIABLE steps to remedy the situation without knowing the CAUSE of the stress!
What irritates me about this stuff is, it's always for some "great good" that it's launched and the money spent, but it INEVITABLY ends up being used against us as farmers/landowners. The famous "LandSat" program started in the 70's is a perfect example. Following on the heels of "extensive and very promising" experiments in "Earth observation" done aboard Skylab and ASTP in the early 70's, LandSat was promised to "revolutionize" the way we assess and evaluate the utilization of the various lands of the Earth, from industrial sites to farmland to urban sprawl to finding new resources in remote parts of the world difficult to locate by ground. While that "noble reason" justified the mission, and much ado was made about the many benefits obtained from the LandSat imagery, over time it has degenerated into being used as a "farmer spysat" by various corporate interests, some of whom have used LandSat imagery in lawsuits against farmers, from the USDA using Landsat imagery to prosecute farmers for planting fields that were supposed to remain unplanted under government programs, to companies using satellite imagery and nefarious trespassing methods of "ground truthing" to determine that some farmers they sued were using GMO seed technology outside the limits of the grower agreements (they were planting home-grown seed mostly).
This is just the latest example... I can EASILY see the greedy traders and speculators on the floors and trading pits of the CBOT and NY Merc and KCBOT salivating over the chance to get their hands on "up to the minute" data on crop conditions across the Midwest (and other crop growing areas of the US, which is EASILY identifiable due to USDA reporting/crop planting certification data, requiring only basic "mapping" software on the computer to collate the areas "certified planted" crop locations with the satellite imagery showing the current "stress levels" of the crop. Even us lowly farmers can obtain current "growing degree days" and drought mapping and other "stress factors" to aid in our management of our crops and livestock using readily available smart phone apps, and there are even more 'in-depth' paid services available by computer... Anybody who doesn't think that this will INEVITABLY be used to manipulate the markets to the farmer's detriment is living in a dream world...
The other side of the coin is, WHO is interpreting the data, and what is their "ax they have to grind". Of course the tree huggers are going to be seeing "methane plumes" from belching livestock, "soil carbon release" from farm tillage, "CO2 increases" from harvested forages, etc.etc.etc... and of course they'll "demand action", even if the conclusions are "fuzzy" at best. It's going to provide a field day for every nutter with a cause, which is precisely what the libtards want... It won't be realists interpreting the data-- it'll be libtard university types that have NO connection to the real world other than screaming for research dollars for their pet project or stirring up their constituency in the radical professional protestor groups "to action" and causing more trouble, more expense, and more difficulty for the average joe, including the ones expected to "feed 9 billion people by the end of the century" (which will never happen anyway).
NASA-- Not About Space Anymore... very sad. I agree COMPLETELY that *IF* this sort of thing HAS to be done, it should be done by NOAA... NOT NASA. NASA should be about SPACE exploration, the other planets and moons in our solar system, NOT EARTH. We've already got a $100 billion dollar boondoggle up there circling the Earth endlessly, which we cannot even access without "thumbing a ride" at $70 million bucks + per person per flight on the Russian Soyuz-- the ISS... more 'peeing in jars, looking at stars'...
Later! OL J R
My MUNIFICENCE is BOUNDLESS, Mr. Bond...