Hi @srathod4 ,
You need to mask pixels having a value of NaN when using Statistical API. Below is an example script:
//VERSION=3
function setup() {
return {
input: [{
bands: ["VV", "VH", "dataMask"]
}],
output: [
{
id: "vv",
sampleType: "FLOAT32",
bands: 1
},
{
id: "vh",
sampleType: "FLOAT32",
bands: 1
},
{
id: "dataMask",
bands: ["vv", "vh"]
}],
mosaicking: "ORBIT"
};
}
function evaluatePixel(samples, scenes) {
let vv_valid = 0;
let vh_valid = 0;
if (samples[0].dataMask === 1 && Number.isFinite(samples[0].VV)) {
vv_valid = 1;
}
if (samples[0].dataMask === 1 && Number.isFinite(samples[0].VH)) {
vh_valid = 1;
}
return {
vv: [samples[0].VV],
vh: [samples[0].VH],
dataMask: [
samples[0].dataMask * vv_valid,
samples[0].dataMask * vh_valid
]
};
}
Thank you!
Could you please help me with the same on this code?
bbox_param = 0.1
# Credentials
# Set up Sentinel Hub configuration
config = SHConfig()
config.sh_client_id = client_id
config.sh_client_secret = client_secret
evalscript = """
//VERSION=3
function setup() {
return {
input: [{
bands: [
"CH4",
"dataMask",
]
}],
output: [
{
id: "data",
noDataValue: -999,
bands:1
},
{
id: "dataMask",
bands: 1
}
]
};
}
function evaluatePixel(sample) {
return {
data: [sample.CH4],
dataMask: [sample.dataMask],
};
}
"""
calculations = {
"default": {
"statistics": {
"default": {
"percentiles": {
"k": [
5,
25,
50,
75,
95
],
"interpolation": "higher"
}
}
}
}
}
# Define the bounding box
# The bounding box is defined by specifying the longitude and latitude coordinates of two opposite corners
# lon1, lat1, lon2, lat2
bbox = BBox(bbox=[loni - bbox_param, lati - bbox_param, loni + bbox_param, lati + bbox_param], crs=CRS.WGS84)
# Create Sentinel Hub statistical request
request = SentinelHubStatistical(
aggregation=SentinelHubStatistical.aggregation(
evalscript=evalscript,
time_interval=(formatted_date0, formatted_date1),
aggregation_interval='P1D'
),
input_data=[
SentinelHubStatistical.input_data(
DataCollection.SENTINEL5P,
other_args={"dataFilter": {"mosaickingOrder": "leastRecent","timeliness": "OFFL"},"processing": {"upsampling": "BICUBIC","downsampling": "BICUBIC","minQa": 30}},
),
],
bbox=bbox,
calculations=calculations,
config=config
)
# Send the request and retrieve the response data
response = request.get_data()
response
Hi @srathod4 ,
You could try to adapt your Evalscript based on the example I provided above. You just need to add a conditional statement in the evaluatePixel function to re-assign 0 to dataMask if sample.CH4 is NaN (Number.isFinite will be false if the value is NaN).
I tried this and it didnt make a lot of difference compared to my original script
function evaluatePixel(sample) {
if (isNaN(sample.CH4) || isNaN(sample.dataMask)) {
return {
data: [null],
dataMask: [null],
};
} else {
return {
data: [sample.CH4],
dataMask: [sample.dataMask],
};
}
}
Hi @srathod4 ,
Please try the following:
//VERSION=3
function setup() {
return {
input: [{
bands: [
"CH4",
"dataMask",
]
}],
output: [
{
id: "data",
bands:1
},
{
id: "dataMask",
bands: 1
}
]
};
}
function evaluatePixel(sample) {
let is_valid = 0;
if (Number.isFinite(sample.CH4) && sample.dataMask === 1) {
is_valid = 1;
}
return {
data: [sample.CH4],
dataMask: [is_valid],
};
}
If you still get a lot of NaNs from the response, please check if there is data available at that time range.
Thank you! It certainly allowed more (2-5%) values to pass over a 10x10km2 box with SIMPLE mosaicking than in my original code. But it also lead to some values now being NaN compared to the original code. I will use your suggested code. Thank you!
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