Just curious, have anyone tried to extract elevation data from LANDSAT or MODIS imagery? So far, I came across one journal by Toutin who did so using adjacent LANDSAT 7 imageries. Results seem pretty decent.
Anyone have any ideas???
[GIS] Extract elevation data from Landsat / MODIS imagery
demelevationlandsatmodisremote sensing
Related Solutions
The full details can be found on the USGS FAQ. Here is a short answer.
Band numbers in Landsat 5 TM and Landsat 7 ETM+ correspond with the same wavelength (approximately). Unfortunately, Landsat 5 Thematic Mapper (TM) operational imaging ended in November 2011. Landsat 5 MSS was powered back on in 2012 and collected data until January 2013. However, there are less bands on Landsat 5 MSS: you will not find the equivalent to Landsat ETM+ bands number 1, 5, 6 and 7 on the Landsat MSS 5 sensor.
Landsat 7 | Landsat 8 | Landsat 5 MSS
1 | 2
2 | 3 | 1
3 | 4 | 2
4 | 5 (both are NIR bands, but narrower band with OLI (landsat 8) than with ETM+) | (3)4
5 | 6
6 | split in 10 and 11 (note that TIRS failed after december 18, 2014 on Landsat 8. EDIT: As mentioned by @Kersten, nominal TIRS acquisition resumed March 7, 2015 and data should be available again around mid-May 2015)
7 | 7
I got the VERY messy code that I use to download all Landsat data by setting Path and Row parameters. Also there are some arcpy and custom functions that is not nescessary for you. You can clear this code to adapt it for your purposes (comments are in russian):
# -*- coding: utf-8 -*-
import os
import sys
import shutil
import subprocess
import traceback
import time
import requests
from pprint import pprint
# выключить предупреждение
requests.packages.urllib3.disable_warnings()
# -----------------------------------------------------------
def find_scenes_in_DB(FC_in_GDB, field_names_list = ['ID', 'ARCHIVE']):
with arcpy.da.SearchCursor(FC_in_GDB, field_names_list) as DB_cursor:
uniq_sat_name = sorted({row[0] for row in DB_cursor})
DB_cursor.reset()
uniq_sat_archive = sorted({row[1] for row in DB_cursor})
uniq_sat_name += uniq_sat_archive
return uniq_sat_name
# -----------------------------------------------------------
# замеры времени
def Time_now():
return time.time()
# -----------------------------------------------------------
def Time_elapsed(time_start, time_end):
return time_end - time_start
# -----------------------------------------------------------
# сгенерировать текст запроса (URL) и вернуть его в виде текста
def generate_json_request(
request_code,
json_request_content,
http_service_endpoint=r'https://earthexplorer.usgs.gov/inventory/json/v/1.4.0/'
):
return str(http_service_endpoint + request_code + r'?jsonRequest=' + json_request_content)
# -----------------------------------------------------------
# авторизироваться на сайте и получить токен доступа
def login(username, password, catalogId, authType = 'EROS'):
URL = generate_json_request(
request_code='login',
json_request_content='{' +
'"username":"' + username +
'","password":"' + password +
'","authType":"' + authType +
'","catalogId":"' + catalogId +
'"}'
)
# послать POST запрос
answer = requests.post(URL)
# проверка прошёл ли запрос
check_answer = (answer.status_code, answer.reason)
if check_answer != (200, 'OK'):
print u'Ошибка! Сайт не доступен.', check_answer, u'Ссылка:'
print URL[:150], '...'
return None
else:
# если ошибка (авторизация провалена)
if answer.json()['errorCode'] is not None:
print u'Ошибка!', answer.json()['errorCode'] + ':', answer.json()['error']
# else:
# print u'Авторизация успешна! Токен:', answer.json()['data']
return answer.json()['data']
# удалить токен авторизации
def logout(apiKey):
if apiKey is not None:
URL = generate_json_request(
request_code='logout',
json_request_content='{"apiKey":"' + apiKey + '"}'
)
# послать POST запрос
answer = requests.post(URL)
# проверка прошёл ли запрос
check_answer = (answer.status_code, answer.reason)
if check_answer != (200, 'OK'):
print u'Ошибка! Сайт не доступен.', check_answer, u'Ссылка:'
print URL[:150], '...'
else:
# если ошибка
if answer.json()['errorCode'] is not None:
# print u'Ошибка!', answer.json()['errorCode'] + ':', answer.json()['error']
return None
else:
# if answer.json()['data'] == False:
# print u'Токен НЕ удалён.'
# pprint(answer.json())
# else:
# print u'Токен удалён.'
return answer.json()['data']
def datasetfields(datasetName, apiKey, node='EE'):
URL = generate_json_request(
request_code='datasetfields',
json_request_content='{"apiKey":"' + apiKey + '", "node": "' + node + '", "datasetName": "' + datasetName + '"}'
)
# послать POST запрос
answer = requests.post(URL)
# проверка прошёл ли запрос
check_answer = (answer.status_code, answer.reason)
if check_answer != (200, 'OK'):
print u'Ошибка! Сайт не доступен.', check_answer, u'Ссылка:'
print URL[:150], '...'
else:
# если ошибка
if answer.json()['errorCode'] is not None:
print u'Ошибка!', answer.json()['errorCode'] + ':', answer.json()['error']
return None
else:
return answer.json()
# сформировать критерий поиска снимков на основе списка Path Row
def additionalCriteria(list_Path_Row, datasetName):
additionalCriteria = '{"filterType":"or", "childFilters":['
# первая итерация?
first_time = True
for x in datasetfields(datasetName, apiKey).get('data'):
if x.get('name') == 'WRS Path': Path_fieldId = x.get('fieldId')
if x.get('name') == 'WRS Row': Row_fieldId = x.get('fieldId')
for PR in list_Path_Row:
Path = str(PR[0])
Row = str(PR[1])
filter_Path = '{"filterType":"value", "fieldId":' + str(Path_fieldId) + ', "value":"' + Path + '", "operand":"="}' # "fieldId":10036 - PATH
filter_Row = '{"filterType":"value", "fieldId":' + str(Row_fieldId) + ', "value":"' + Row + '", "operand":"="}' # "fieldId":10038 - ROW
filter_And = '{"filterType":"and", "childFilters":[' + filter_Path + ',' + filter_Row + ']}'
# если первая - не добавляем запятую в начало
if first_time == True:
additionalCriteria += filter_And
first_time = False
else:
additionalCriteria += ' ,' + filter_And
additionalCriteria += ']}'
return additionalCriteria
# поиск снимков
def search_scenes(datasetName, list_Path_Row, apiKey,
startDate='2016-05-01T00:00:00Z',
endDate='2100-01-01T00:00:00Z',
months=[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12],
maxResults=10,
):
URL = generate_json_request(
request_code='search',
json_request_content='{"datasetName":"' + datasetName + '"' + \
',"temporalFilter":{"dateField": "search_date","startDate":"' + startDate + '","endDate":"' + endDate + '"}' + \
',"months":' + str(months) + \
',"maxResults":' + str(maxResults) + \
',"additionalCriteria":' + additionalCriteria(list_Path_Row, datasetName) + \
',"node":"EE","apiKey":"' + apiKey + '"}'
)
# послать POST запрос
answer = requests.post(URL)
# проверка прошёл ли запрос
check_answer = (answer.status_code, answer.reason)
if check_answer != (200, 'OK'):
print u'Ошибка! Сайт не доступен.', check_answer, u'Ссылка:'
print URL[:150], '...'
print
print URL
else:
# если ошибка
if answer.json()['errorCode'] is not None:
print u'Ошибка!', answer.json()['errorCode'] + ':', answer.json()['error']
return None
else:
if answer.json()['data'] in (None, ''):
print u'Снимков не найдено.'
else:
number_of_scenes = answer.json()['data']['totalHits']
dwnld_URL_list = []
for scene in answer.json()['data']['results']:
dwnld_URL_list.append(scene['entityId'])
return dwnld_URL_list
# вернуть список URL для прямой закачки снимков
def get_download_list(datasetName, entityIds, apiKey, node='EE', products='["STANDARD"]'):
entityIds = str(['"' + x.encode('UTF8') + '"' for x in entityIds]).replace("'", '')
URL = generate_json_request(
request_code='download',
json_request_content='{' + \
'"datasetName": "' + datasetName + '",' + \
'"apiKey": "' + apiKey + '",' + \
'"node": "' + node + '",' + \
'"entityIds": ' + str(entityIds) + ',' + \
'"products": ' + products + \
'}'
)
# послать POST запрос
answer = requests.post(URL)
# проверка прошёл ли запрос
check_answer = (answer.status_code, answer.reason)
if check_answer != (200, 'OK'):
print u'Ошибка! Сайт не доступен.', check_answer, u'Ссылка:'
print URL[:150], '...'
return None
else:
# если ошибка (авторизация провалена)
if answer.json()['errorCode'] is not None:
print u'Ошибка!', answer.json()['errorCode'] + ':', answer.json()['error']
return answer.json()['data']
# делаем список уже закаченных файлов
def list_of_scenes_in_archive(archive_path):
# archive_path = archive_path.decode('utf-8')
loaded = []
dirList = os.listdir(archive_path)
for fname in dirList:
fname = fname[:fname.rfind('.')] # удаляются 4 последних знака (в моём случае это ".rar")
loaded.append(fname)
return loaded
# скачать и сохранить файл
def download_file(url, file_path):
r = requests.get(url, timeout=120, stream=True)
with open(file_path, 'wb') as f:
for chunk in r.iter_content(chunk_size=1024):
f.write(chunk)
return file_path
# тестировать файл формата tar.gz
def test_gz_archive(archive_path, GZIP_path):
coding = 'cp1251'
GZIP_path = GZIP_path.encode(coding)
archive_path = archive_path.encode(coding)
cmd_list = [GZIP_path, '-t', archive_path]
# запуск консоли и выполнение команды в скрытном режиме с выводом
subprocess.check_output(cmd_list, stderr=subprocess.STDOUT, shell=True)
def main(username, password, catalogId, datasets, WRS_2_Path_Row_list, WRS_1_Path_Row_list, archive_path, temp_dwnld_folder, FC_in_GDB):
while True:
try:
print time.strftime("%d.%m.%Y %H:%M:%S"),
global apiKey # глобальная переменная!!!
apiKey = login(username, password, catalogId) # авторизация
# список уже закаченных снимков
loaded = list_of_scenes_in_archive(archive_path)
print u"Всего файлов в локальном хранилище:", len(loaded)
loaded_2 = find_scenes_in_DB(FC_in_GDB)
loaded += loaded_2
for dataset in datasets:
# print '---------------------------'
print u'Набор данных:', dataset
if dataset in 'LANDSAT_MSS':
list_Path_Row = WRS_1_Path_Row_list
else:
list_Path_Row = WRS_2_Path_Row_list
# делаем запросы на каждый отдельный Path-Row, чтобы не превысить ограничение по длине URL
for path_row in list_Path_Row:
entityIds = search_scenes(datasetName=dataset,
list_Path_Row=[path_row],
apiKey=apiKey,
maxResults=50000)
# список сцен которых нет в архиве
dwnld_list = list(set(entityIds) - set(loaded))
if len(dwnld_list) > 0:
print time.strftime("%d.%m.%Y %H:%M:%S"),
print u'Path Row:', str(path_row[0]), str(path_row[1]) + '.',
print u'Всего снимков:', str(len(entityIds)) + '.',
print u'Новых:', str(len(dwnld_list)) + '.',
print u'Закачка файлов:'
# получаем сслыку на закачку для каждой отдельной сцены
for (scene_num, dwnld_scene) in enumerate(dwnld_list):
DICTs_list = get_download_list(dataset, [dwnld_scene], apiKey, node='EE',
products='["STANDARD"]')
# скачать снимки
for DICT in DICTs_list:
print time.strftime("%d.%m.%Y %H:%M:%S"), u'Cнимок:',
URL = DICT[u'url']
# формирование пути
scene_product_ID = URL[URL.rfind('/') + 1:URL.rfind('.tar.gz?')] # название снимка по-новому
scene_ID = DICT[u'entityId'] # название снимка по-старому
scene_path = os.path.join(temp_dwnld_folder, scene_product_ID + u'.tar.gz')
print str(scene_num + 1), scene_product_ID
time_start = Time_now() # текущее время (начало закачки)
try:
## print
## print '-'*10
## print URL
## print scene_path
real_file_len = requests.head(URL).headers[
'content-length'] # размер файла на сервере
download_file(URL, scene_path) # закачка
dwnld_file_len = str(long(os.path.getsize(scene_path))) # размер закаченного файла
if os.path.isfile(scene_path):
if real_file_len != dwnld_file_len:
os.remove(scene_path)
print u'<= DEL, файл не докачался'
# print real_file_len
# print dwnld_file_len
# print real_file_len == dwnld_file_len
# print '-'*10
# проверка архива
# test_gz_archive(scene_path, GZIP_path = ur'G:\Install\GZIP\gzip.exe')
if scene_num + 1 != len(dwnld_list): # вывести запятую
print ',',
# если ошибка при закачке - удалить недокаченный файл
except:
print u'<= DEL,',
if os.path.isfile(scene_path):
os.remove(scene_path)
traceback.print_exc() # напечатать ошибку
time_end = Time_now() # текущее время (конец закачки)
# если закачка была менее или равно 60 минут назад
if Time_elapsed(time_start, time_end) <= 60 * 60:
logout(apiKey)
apiKey = login(username, password, catalogId) # авторизация
elif Time_elapsed(time_start, time_end) > 60 * 60:
apiKey = login(username, password, catalogId) # авторизация
# если авторизация была успешной - удалить токен авторизации
if apiKey is not None: logout(apiKey)
# если в процессе выполнения была ошибка
except:
try:
logout(apiKey) # удалить токен авторизации
except:
pass
print
traceback.print_exc() # напечатать ошибку
print time.strftime("%d.%m.%Y %H:%M:%S") + u' =========== Повтор через час ===========\n'
time.sleep(3600)
if __name__ == "__main__":
WRS_2_Path_Row_list=[
[165, 14], [166, 14],
]
WRS_1_Path_Row_list=[
[182, 13], [176, 14],
]
main(
username='username',
password='password',
catalogId = "EE", # возможные параметры catalogId: "EE" "GLOVIS" "HDDS" "LPCS"
datasets=[
'LANDSAT_8_C1',
## 'LANDSAT_8_PREWRS',
## 'LANDSAT_ETM_C1',
## 'LANDSAT_TM_C1',
## 'LANDSAT_MSS',
],
WRS_2_Path_Row_list=WRS_2_Path_Row_list,
WRS_1_Path_Row_list=WRS_1_Path_Row_list,
archive_path=ur"S:\Landsat",
temp_dwnld_folder=ur'G:\temp'
)
# LANDSAT_8_C1 Landsat 8 Operational Land Imager and Thermal Infrared Sensor Collection 1 Level-1
# LANDSAT_8_PREWRS Landsat 8 Operational Land Imager and Thermal Infrared Sensor Pre-WRS-2: 2013
# LANDSAT_ETM_C1 Landsat 7 Enhanced Thematic Mapper Plus Collection 1 Level-1
# LANDSAT_TM_C1 Landsat 4-5 Thematic Mapper Collection 1 Level-1
# LANDSAT_MSS Landsat 1-5 Multispectral Scanner: 1972-2013
Best Answer
Landsat and Modis are optical sensors, which means that they provide digital numbers of reflected materials that are within the electromagnetic spectrum. These values correspond to the wave length of the corresponding satellite band. To get elevation from just the raw values would be impossible. The only potential means to collect elevation information would be to have stereo pairs and collect elevation from stereo compilation. Please share the link to the journal so we can all review the article and comment accordingly.